data_type large_stringclasses 3
values | source large_stringclasses 29
values | code large_stringlengths 98 49.4M | filepath large_stringlengths 5 161 ⌀ | message large_stringclasses 234
values | commit large_stringclasses 234
values | subject large_stringclasses 418
values | critique large_stringlengths 101 1.26M ⌀ | metadata dict |
|---|---|---|---|---|---|---|---|---|
lkml_critique | lkml | The latest MC firmware version added a new command to retrieve all DPMAC
counters in a single firmware call. Use this new command, when possible,
in dpaa2-mac as well.
In order to use the dpmac_get_statistics() API, two DMA memory areas are
used: one to transmit what counters the driver is requesting and one to
receiv... | null | null | null | [PATCH net-next 2/5] net: dpaa2-mac: retrieve MAC statistics in one firmware command | Jakub Kicinski <kuba@kernel.org> writes:
I think the expectation is that by default, tests written in Bash are
run on one machine without remotes.
I think this fundamentally stems from the fact that running processes in
Python is a bit unwieldy, so it makes sense to have helpers, so
everybody uses them, so you can h... | {
"author": "Petr Machata <petrm@nvidia.com>",
"date": "Fri, 27 Feb 2026 14:53:06 +0100",
"is_openbsd": false,
"thread_id": "87ms0ufc0p.fsf@nvidia.com.mbox.gz"
} |
lkml_critique | lkml | Hey,
This reworks the simple_xattr infrastructure and adds support for
user.* extended attributes on sockets.
The simple_xattr subsystem currently uses an rbtree protected by a
reader-writer spinlock. This series replaces the rbtree with an
rhashtable giving O(1) average-case lookup with RCU-based lockless
reads. Thi... | null | null | null | [PATCH 00/14] xattr: rework simple xattrs and support user.*
xattrs on sockets | In preparation for converting simple_xattrs from rbtree to rhashtable,
add rhash_head and rcu_head members to struct simple_xattr. The
rhashtable implementation will use rhash_head for hash table linkage
and RCU-based lockless reads, requiring that replaced or removed xattr
entries be freed via call_rcu() rather than i... | {
"author": "Christian Brauner <brauner@kernel.org>",
"date": "Mon, 16 Feb 2026 14:31:57 +0100",
"is_openbsd": false,
"thread_id": "yqxanlt3h4h2dwtpzgywsrzozdry3oe3c4yg22x6wqm2grntbu@pazi2ufzrwfv.mbox.gz"
} |
lkml_critique | lkml | Hey,
This reworks the simple_xattr infrastructure and adds support for
user.* extended attributes on sockets.
The simple_xattr subsystem currently uses an rbtree protected by a
reader-writer spinlock. This series replaces the rbtree with an
rhashtable giving O(1) average-case lookup with RCU-based lockless
reads. Thi... | null | null | null | [PATCH 00/14] xattr: rework simple xattrs and support user.*
xattrs on sockets | Add rhashtable support to the simple_xattr subsystem while keeping the
existing rbtree code fully functional. This allows consumers to be
migrated one at a time without breaking any intermediate build.
struct simple_xattrs gains a dispatch flag and a union holding either
the rbtree (rb_root + rwlock) or rhashtable sta... | {
"author": "Christian Brauner <brauner@kernel.org>",
"date": "Mon, 16 Feb 2026 14:31:58 +0100",
"is_openbsd": false,
"thread_id": "yqxanlt3h4h2dwtpzgywsrzozdry3oe3c4yg22x6wqm2grntbu@pazi2ufzrwfv.mbox.gz"
} |
lkml_critique | lkml | Hey,
This reworks the simple_xattr infrastructure and adds support for
user.* extended attributes on sockets.
The simple_xattr subsystem currently uses an rbtree protected by a
reader-writer spinlock. This series replaces the rbtree with an
rhashtable giving O(1) average-case lookup with RCU-based lockless
reads. Thi... | null | null | null | [PATCH 00/14] xattr: rework simple xattrs and support user.*
xattrs on sockets | Adapt tmpfs/shmem to use the rhashtable-based xattr path and switch
from an embedded struct to pointer-based lazy allocation.
Change shmem_inode_info.xattrs from embedded 'struct simple_xattrs' to
a pointer 'struct simple_xattrs *', initialized to NULL. This avoids
the rhashtable overhead for every tmpfs inode, which ... | {
"author": "Christian Brauner <brauner@kernel.org>",
"date": "Mon, 16 Feb 2026 14:31:59 +0100",
"is_openbsd": false,
"thread_id": "yqxanlt3h4h2dwtpzgywsrzozdry3oe3c4yg22x6wqm2grntbu@pazi2ufzrwfv.mbox.gz"
} |
lkml_critique | lkml | Hey,
This reworks the simple_xattr infrastructure and adds support for
user.* extended attributes on sockets.
The simple_xattr subsystem currently uses an rbtree protected by a
reader-writer spinlock. This series replaces the rbtree with an
rhashtable giving O(1) average-case lookup with RCU-based lockless
reads. Thi... | null | null | null | [PATCH 00/14] xattr: rework simple xattrs and support user.*
xattrs on sockets | Adapt kernfs to use the rhashtable-based xattr path and switch from an
embedded struct to pointer-based lazy allocation.
Change kernfs_iattrs.xattrs from embedded 'struct simple_xattrs' to a
pointer 'struct simple_xattrs *', initialized to NULL (zeroed by
kmem_cache_zalloc). Since kernfs_iattrs is already lazily alloc... | {
"author": "Christian Brauner <brauner@kernel.org>",
"date": "Mon, 16 Feb 2026 14:32:00 +0100",
"is_openbsd": false,
"thread_id": "yqxanlt3h4h2dwtpzgywsrzozdry3oe3c4yg22x6wqm2grntbu@pazi2ufzrwfv.mbox.gz"
} |
lkml_critique | lkml | Hey,
This reworks the simple_xattr infrastructure and adds support for
user.* extended attributes on sockets.
The simple_xattr subsystem currently uses an rbtree protected by a
reader-writer spinlock. This series replaces the rbtree with an
rhashtable giving O(1) average-case lookup with RCU-based lockless
reads. Thi... | null | null | null | [PATCH 00/14] xattr: rework simple xattrs and support user.*
xattrs on sockets | Adapt pidfs to use the rhashtable-based xattr path by switching from a
dedicated slab cache to simple_xattrs_alloc().
Previously pidfs used a custom kmem_cache (pidfs_xattr_cachep) that
allocated a struct containing an embedded simple_xattrs plus
simple_xattrs_init(). Replace this with simple_xattrs_alloc() which
comb... | {
"author": "Christian Brauner <brauner@kernel.org>",
"date": "Mon, 16 Feb 2026 14:32:01 +0100",
"is_openbsd": false,
"thread_id": "yqxanlt3h4h2dwtpzgywsrzozdry3oe3c4yg22x6wqm2grntbu@pazi2ufzrwfv.mbox.gz"
} |
lkml_critique | lkml | Hey,
This reworks the simple_xattr infrastructure and adds support for
user.* extended attributes on sockets.
The simple_xattr subsystem currently uses an rbtree protected by a
reader-writer spinlock. This series replaces the rbtree with an
rhashtable giving O(1) average-case lookup with RCU-based lockless
reads. Thi... | null | null | null | [PATCH 00/14] xattr: rework simple xattrs and support user.*
xattrs on sockets | Now that all consumers (shmem, kernfs, pidfs) have been converted to
use the rhashtable-based simple_xattrs with pointer-based lazy
allocation, remove the legacy rbtree code path. The rhashtable
implementation provides O(1) average-case lookup with RCU-based lockless
reads, replacing the O(log n) rbtree with reader-wri... | {
"author": "Christian Brauner <brauner@kernel.org>",
"date": "Mon, 16 Feb 2026 14:32:02 +0100",
"is_openbsd": false,
"thread_id": "yqxanlt3h4h2dwtpzgywsrzozdry3oe3c4yg22x6wqm2grntbu@pazi2ufzrwfv.mbox.gz"
} |
lkml_critique | lkml | Hey,
This reworks the simple_xattr infrastructure and adds support for
user.* extended attributes on sockets.
The simple_xattr subsystem currently uses an rbtree protected by a
reader-writer spinlock. This series replaces the rbtree with an
rhashtable giving O(1) average-case lookup with RCU-based lockless
reads. Thi... | null | null | null | [PATCH 00/14] xattr: rework simple xattrs and support user.*
xattrs on sockets | Stop repeating the ?: in multiple places and use a simple helper for
this.
Signed-off-by: Christian Brauner <brauner@kernel.org>
---
fs/xattr.c | 11 +++++++++--
1 file changed, 9 insertions(+), 2 deletions(-)
diff --git a/fs/xattr.c b/fs/xattr.c
index 64803097e1dc..c4db8663c32e 100644
--- a/fs/xattr.c
+++ b/fs/xatt... | {
"author": "Christian Brauner <brauner@kernel.org>",
"date": "Mon, 16 Feb 2026 14:32:03 +0100",
"is_openbsd": false,
"thread_id": "yqxanlt3h4h2dwtpzgywsrzozdry3oe3c4yg22x6wqm2grntbu@pazi2ufzrwfv.mbox.gz"
} |
lkml_critique | lkml | Hey,
This reworks the simple_xattr infrastructure and adds support for
user.* extended attributes on sockets.
The simple_xattr subsystem currently uses an rbtree protected by a
reader-writer spinlock. This series replaces the rbtree with an
rhashtable giving O(1) average-case lookup with RCU-based lockless
reads. Thi... | null | null | null | [PATCH 00/14] xattr: rework simple xattrs and support user.*
xattrs on sockets | Simplify the codeflow by using a switch statement that switches on
S_IFMT.
Signed-off-by: Christian Brauner <brauner@kernel.org>
---
fs/xattr.c | 18 +++++++++++++-----
1 file changed, 13 insertions(+), 5 deletions(-)
diff --git a/fs/xattr.c b/fs/xattr.c
index c4db8663c32e..328ed7558dfc 100644
--- a/fs/xattr.c
+++ b... | {
"author": "Christian Brauner <brauner@kernel.org>",
"date": "Mon, 16 Feb 2026 14:32:04 +0100",
"is_openbsd": false,
"thread_id": "yqxanlt3h4h2dwtpzgywsrzozdry3oe3c4yg22x6wqm2grntbu@pazi2ufzrwfv.mbox.gz"
} |
lkml_critique | lkml | Hey,
This reworks the simple_xattr infrastructure and adds support for
user.* extended attributes on sockets.
The simple_xattr subsystem currently uses an rbtree protected by a
reader-writer spinlock. This series replaces the rbtree with an
rhashtable giving O(1) average-case lookup with RCU-based lockless
reads. Thi... | null | null | null | [PATCH 00/14] xattr: rework simple xattrs and support user.*
xattrs on sockets | Signed-off-by: Christian Brauner <brauner@kernel.org>
---
fs/kernfs/inode.c | 75 ++-------------------------------------------
fs/kernfs/kernfs-internal.h | 3 +-
fs/xattr.c | 65 +++++++++++++++++++++++++++++++++++++++
include/linux/kernfs.h | 2 --
include/linux/xattr.h | 18 ... | {
"author": "Christian Brauner <brauner@kernel.org>",
"date": "Mon, 16 Feb 2026 14:32:05 +0100",
"is_openbsd": false,
"thread_id": "yqxanlt3h4h2dwtpzgywsrzozdry3oe3c4yg22x6wqm2grntbu@pazi2ufzrwfv.mbox.gz"
} |
lkml_critique | lkml | Hey,
This reworks the simple_xattr infrastructure and adds support for
user.* extended attributes on sockets.
The simple_xattr subsystem currently uses an rbtree protected by a
reader-writer spinlock. This series replaces the rbtree with an
rhashtable giving O(1) average-case lookup with RCU-based lockless
reads. Thi... | null | null | null | [PATCH 00/14] xattr: rework simple xattrs and support user.*
xattrs on sockets | Now that we've generalized the infrastructure for user.* xattrs make it
possible to set up to 128 user.* extended attributes on a sockfs inode
or up to 128kib. kernfs (cgroupfs) has the same limits and it has proven
to be quite sufficient for nearly all use-cases.
This will allow containers to label sockets and will e... | {
"author": "Christian Brauner <brauner@kernel.org>",
"date": "Mon, 16 Feb 2026 14:32:06 +0100",
"is_openbsd": false,
"thread_id": "yqxanlt3h4h2dwtpzgywsrzozdry3oe3c4yg22x6wqm2grntbu@pazi2ufzrwfv.mbox.gz"
} |
lkml_critique | lkml | Hey,
This reworks the simple_xattr infrastructure and adds support for
user.* extended attributes on sockets.
The simple_xattr subsystem currently uses an rbtree protected by a
reader-writer spinlock. This series replaces the rbtree with an
rhashtable giving O(1) average-case lookup with RCU-based lockless
reads. Thi... | null | null | null | [PATCH 00/14] xattr: rework simple xattrs and support user.*
xattrs on sockets | Allow user.* extended attributes on sockets by adding S_IFSOCK to the
xattr_permission() switch statement. Previously user.* xattrs were only
permitted on regular files and directories. Symlinks and special files
including sockets were rejected with -EPERM.
Path-based AF_UNIX sockets have their inodes on the underlyin... | {
"author": "Christian Brauner <brauner@kernel.org>",
"date": "Mon, 16 Feb 2026 14:32:07 +0100",
"is_openbsd": false,
"thread_id": "yqxanlt3h4h2dwtpzgywsrzozdry3oe3c4yg22x6wqm2grntbu@pazi2ufzrwfv.mbox.gz"
} |
lkml_critique | lkml | Hey,
This reworks the simple_xattr infrastructure and adds support for
user.* extended attributes on sockets.
The simple_xattr subsystem currently uses an rbtree protected by a
reader-writer spinlock. This series replaces the rbtree with an
rhashtable giving O(1) average-case lookup with RCU-based lockless
reads. Thi... | null | null | null | [PATCH 00/14] xattr: rework simple xattrs and support user.*
xattrs on sockets | Test user.* extended attribute operations on path-based Unix domain
sockets (SOCK_STREAM, SOCK_DGRAM, SOCK_SEQPACKET). Path-based sockets
are bound to a filesystem path and their inodes live on the underlying
filesystem (e.g. tmpfs).
Covers set/get/list/remove, persistence, XATTR_CREATE/XATTR_REPLACE
flags, empty valu... | {
"author": "Christian Brauner <brauner@kernel.org>",
"date": "Mon, 16 Feb 2026 14:32:08 +0100",
"is_openbsd": false,
"thread_id": "yqxanlt3h4h2dwtpzgywsrzozdry3oe3c4yg22x6wqm2grntbu@pazi2ufzrwfv.mbox.gz"
} |
lkml_critique | lkml | Hey,
This reworks the simple_xattr infrastructure and adds support for
user.* extended attributes on sockets.
The simple_xattr subsystem currently uses an rbtree protected by a
reader-writer spinlock. This series replaces the rbtree with an
rhashtable giving O(1) average-case lookup with RCU-based lockless
reads. Thi... | null | null | null | [PATCH 00/14] xattr: rework simple xattrs and support user.*
xattrs on sockets | Test user.* extended attribute operations on sockfs sockets. Sockets
created via socket() have their inodes in sockfs, which now supports
user.* xattrs with per-inode limits.
Tests fsetxattr/fgetxattr/flistxattr/fremovexattr operations including
set/get, listing (verifies system.sockprotoname presence), remove,
update... | {
"author": "Christian Brauner <brauner@kernel.org>",
"date": "Mon, 16 Feb 2026 14:32:09 +0100",
"is_openbsd": false,
"thread_id": "yqxanlt3h4h2dwtpzgywsrzozdry3oe3c4yg22x6wqm2grntbu@pazi2ufzrwfv.mbox.gz"
} |
lkml_critique | lkml | Hey,
This reworks the simple_xattr infrastructure and adds support for
user.* extended attributes on sockets.
The simple_xattr subsystem currently uses an rbtree protected by a
reader-writer spinlock. This series replaces the rbtree with an
rhashtable giving O(1) average-case lookup with RCU-based lockless
reads. Thi... | null | null | null | [PATCH 00/14] xattr: rework simple xattrs and support user.*
xattrs on sockets | Test user.* xattr operations on sockets from different address families:
AF_INET, AF_INET6, AF_NETLINK, and AF_PACKET. All socket types use
sockfs for their inodes, so user.* xattrs should work regardless of
address family.
Each fixture creates a socket (no bind needed) and verifies the full
fsetxattr/fgetxattr/flistx... | {
"author": "Christian Brauner <brauner@kernel.org>",
"date": "Mon, 16 Feb 2026 14:32:10 +0100",
"is_openbsd": false,
"thread_id": "yqxanlt3h4h2dwtpzgywsrzozdry3oe3c4yg22x6wqm2grntbu@pazi2ufzrwfv.mbox.gz"
} |
lkml_critique | lkml | Hey,
This reworks the simple_xattr infrastructure and adds support for
user.* extended attributes on sockets.
The simple_xattr subsystem currently uses an rbtree protected by a
reader-writer spinlock. This series replaces the rbtree with an
rhashtable giving O(1) average-case lookup with RCU-based lockless
reads. Thi... | null | null | null | [PATCH 00/14] xattr: rework simple xattrs and support user.*
xattrs on sockets | On Mon, Feb 16, 2026 at 02:31:56PM +0100, Christian Brauner wrote:
Patches 1-6 look ok to me, at least in the sense that nothing stood out
to me as obviously wrong, so
Acked-by: "Darrick J. Wong" <djwong@kernel.org>
Hum. I suppose there's never going to be a central varlink broker, is
there? That doesn't sound gre... | {
"author": "\"Darrick J. Wong\" <djwong@kernel.org>",
"date": "Thu, 19 Feb 2026 16:44:54 -0800",
"is_openbsd": false,
"thread_id": "yqxanlt3h4h2dwtpzgywsrzozdry3oe3c4yg22x6wqm2grntbu@pazi2ufzrwfv.mbox.gz"
} |
lkml_critique | lkml | Hey,
This reworks the simple_xattr infrastructure and adds support for
user.* extended attributes on sockets.
The simple_xattr subsystem currently uses an rbtree protected by a
reader-writer spinlock. This series replaces the rbtree with an
rhashtable giving O(1) average-case lookup with RCU-based lockless
reads. Thi... | null | null | null | [PATCH 00/14] xattr: rework simple xattrs and support user.*
xattrs on sockets | On Thu, Feb 19, 2026 at 04:44:54PM -0800, Darrick J. Wong wrote:
Varlink was explicitly designed to avoid having to have a broker.
Practically it would have been one option to have a a central registry
maintained as a bpf socket map. My naive take had always been something
like: systemd can have a global socket map. s... | {
"author": "Christian Brauner <brauner@kernel.org>",
"date": "Fri, 20 Feb 2026 10:23:55 +0100",
"is_openbsd": false,
"thread_id": "yqxanlt3h4h2dwtpzgywsrzozdry3oe3c4yg22x6wqm2grntbu@pazi2ufzrwfv.mbox.gz"
} |
lkml_critique | lkml | Hey,
This reworks the simple_xattr infrastructure and adds support for
user.* extended attributes on sockets.
The simple_xattr subsystem currently uses an rbtree protected by a
reader-writer spinlock. This series replaces the rbtree with an
rhashtable giving O(1) average-case lookup with RCU-based lockless
reads. Thi... | null | null | null | [PATCH 00/14] xattr: rework simple xattrs and support user.*
xattrs on sockets | On Mon, Feb 16, 2026 at 02:32:05PM +0100, Christian Brauner wrote:
I know you're just moving code around and that looks ok, but:
I guess this means you can't have more than 128 xattrs total, and
sum(values) must be less than 128k? The fixed limit is a little odd,
but it's all pinned kernel memory, right?
(IOWs, yo... | {
"author": "\"Darrick J. Wong\" <djwong@kernel.org>",
"date": "Fri, 20 Feb 2026 16:03:26 -0800",
"is_openbsd": false,
"thread_id": "yqxanlt3h4h2dwtpzgywsrzozdry3oe3c4yg22x6wqm2grntbu@pazi2ufzrwfv.mbox.gz"
} |
lkml_critique | lkml | Hey,
This reworks the simple_xattr infrastructure and adds support for
user.* extended attributes on sockets.
The simple_xattr subsystem currently uses an rbtree protected by a
reader-writer spinlock. This series replaces the rbtree with an
rhashtable giving O(1) average-case lookup with RCU-based lockless
reads. Thi... | null | null | null | [PATCH 00/14] xattr: rework simple xattrs and support user.*
xattrs on sockets | On Fri, Feb 20, 2026 at 10:23:55AM +0100, Christian Brauner wrote:
The rest look fine too, modulo my comments about the fixed limits.
Acked-by: "Darrick J. Wong" <djwong@kernel.org>
--D | {
"author": "\"Darrick J. Wong\" <djwong@kernel.org>",
"date": "Fri, 20 Feb 2026 16:14:57 -0800",
"is_openbsd": false,
"thread_id": "yqxanlt3h4h2dwtpzgywsrzozdry3oe3c4yg22x6wqm2grntbu@pazi2ufzrwfv.mbox.gz"
} |
lkml_critique | lkml | Hey,
This reworks the simple_xattr infrastructure and adds support for
user.* extended attributes on sockets.
The simple_xattr subsystem currently uses an rbtree protected by a
reader-writer spinlock. This series replaces the rbtree with an
rhashtable giving O(1) average-case lookup with RCU-based lockless
reads. Thi... | null | null | null | [PATCH 00/14] xattr: rework simple xattrs and support user.*
xattrs on sockets | On Fri, Feb 20, 2026 at 04:03:26PM -0800, Darrick J. Wong wrote:
Yeah, it's all pinned kernel memory.
First time I've seen that. Very creative. But no, I've not done that.
cgroupfs has been fine with a fixed limit for a long time no so for now
it's fine to assume sockfs will be as well. | {
"author": "Christian Brauner <brauner@kernel.org>",
"date": "Mon, 23 Feb 2026 13:13:13 +0100",
"is_openbsd": false,
"thread_id": "yqxanlt3h4h2dwtpzgywsrzozdry3oe3c4yg22x6wqm2grntbu@pazi2ufzrwfv.mbox.gz"
} |
lkml_critique | lkml | Hey,
This reworks the simple_xattr infrastructure and adds support for
user.* extended attributes on sockets.
The simple_xattr subsystem currently uses an rbtree protected by a
reader-writer spinlock. This series replaces the rbtree with an
rhashtable giving O(1) average-case lookup with RCU-based lockless
reads. Thi... | null | null | null | [PATCH 00/14] xattr: rework simple xattrs and support user.*
xattrs on sockets | On Mon 16-02-26 14:31:57, Christian Brauner wrote:
Looks good. Feel free to add:
Reviewed-by: Jan Kara <jack@suse.cz>
Honza
--
Jan Kara <jack@suse.com>
SUSE Labs, CR | {
"author": "Jan Kara <jack@suse.cz>",
"date": "Fri, 27 Feb 2026 15:43:28 +0100",
"is_openbsd": false,
"thread_id": "yqxanlt3h4h2dwtpzgywsrzozdry3oe3c4yg22x6wqm2grntbu@pazi2ufzrwfv.mbox.gz"
} |
lkml_critique | lkml | Hey,
This reworks the simple_xattr infrastructure and adds support for
user.* extended attributes on sockets.
The simple_xattr subsystem currently uses an rbtree protected by a
reader-writer spinlock. This series replaces the rbtree with an
rhashtable giving O(1) average-case lookup with RCU-based lockless
reads. Thi... | null | null | null | [PATCH 00/14] xattr: rework simple xattrs and support user.*
xattrs on sockets | On Mon 16-02-26 14:31:58, Christian Brauner wrote:
Looks good. Feel free to add:
Reviewed-by: Jan Kara <jack@suse.cz>
Honza
--
Jan Kara <jack@suse.com>
SUSE Labs, CR | {
"author": "Jan Kara <jack@suse.cz>",
"date": "Fri, 27 Feb 2026 15:43:41 +0100",
"is_openbsd": false,
"thread_id": "yqxanlt3h4h2dwtpzgywsrzozdry3oe3c4yg22x6wqm2grntbu@pazi2ufzrwfv.mbox.gz"
} |
lkml_critique | lkml | Hey,
This reworks the simple_xattr infrastructure and adds support for
user.* extended attributes on sockets.
The simple_xattr subsystem currently uses an rbtree protected by a
reader-writer spinlock. This series replaces the rbtree with an
rhashtable giving O(1) average-case lookup with RCU-based lockless
reads. Thi... | null | null | null | [PATCH 00/14] xattr: rework simple xattrs and support user.*
xattrs on sockets | On Mon 16-02-26 14:31:59, Christian Brauner wrote:
Looks good. Feel free to add:
Reviewed-by: Jan Kara <jack@suse.cz>
Honza
--
Jan Kara <jack@suse.com>
SUSE Labs, CR | {
"author": "Jan Kara <jack@suse.cz>",
"date": "Fri, 27 Feb 2026 15:48:40 +0100",
"is_openbsd": false,
"thread_id": "yqxanlt3h4h2dwtpzgywsrzozdry3oe3c4yg22x6wqm2grntbu@pazi2ufzrwfv.mbox.gz"
} |
lkml_critique | lkml | Hey,
This reworks the simple_xattr infrastructure and adds support for
user.* extended attributes on sockets.
The simple_xattr subsystem currently uses an rbtree protected by a
reader-writer spinlock. This series replaces the rbtree with an
rhashtable giving O(1) average-case lookup with RCU-based lockless
reads. Thi... | null | null | null | [PATCH 00/14] xattr: rework simple xattrs and support user.*
xattrs on sockets | On Mon 16-02-26 14:32:00, Christian Brauner wrote:
...
This is a slight change in the lifetime rules because previously kernfs
xattrs could be safely accessed only under RCU but after this change you
have to hold inode reference *and* RCU to safely access them. I don't think
anybody would be accessing xattrs without... | {
"author": "Jan Kara <jack@suse.cz>",
"date": "Fri, 27 Feb 2026 16:00:37 +0100",
"is_openbsd": false,
"thread_id": "yqxanlt3h4h2dwtpzgywsrzozdry3oe3c4yg22x6wqm2grntbu@pazi2ufzrwfv.mbox.gz"
} |
lkml_critique | lkml | Hey,
This reworks the simple_xattr infrastructure and adds support for
user.* extended attributes on sockets.
The simple_xattr subsystem currently uses an rbtree protected by a
reader-writer spinlock. This series replaces the rbtree with an
rhashtable giving O(1) average-case lookup with RCU-based lockless
reads. Thi... | null | null | null | [PATCH 00/14] xattr: rework simple xattrs and support user.*
xattrs on sockets | On Mon 16-02-26 14:32:01, Christian Brauner wrote:
One question below:
So you bother with postponing the freeing to a scheduled work because
put_pid() can be called from a context where acquiring rcu to iterate
rhashtable would not be possible? Frankly I have hard time imagining such
context (where previous rbtree c... | {
"author": "Jan Kara <jack@suse.cz>",
"date": "Fri, 27 Feb 2026 16:09:15 +0100",
"is_openbsd": false,
"thread_id": "yqxanlt3h4h2dwtpzgywsrzozdry3oe3c4yg22x6wqm2grntbu@pazi2ufzrwfv.mbox.gz"
} |
lkml_critique | lkml | Hey,
This reworks the simple_xattr infrastructure and adds support for
user.* extended attributes on sockets.
The simple_xattr subsystem currently uses an rbtree protected by a
reader-writer spinlock. This series replaces the rbtree with an
rhashtable giving O(1) average-case lookup with RCU-based lockless
reads. Thi... | null | null | null | [PATCH 00/14] xattr: rework simple xattrs and support user.*
xattrs on sockets | On Mon 16-02-26 14:32:02, Christian Brauner wrote:
Looks good. Feel free to add:
Reviewed-by: Jan Kara <jack@suse.cz>
Honza
--
Jan Kara <jack@suse.com>
SUSE Labs, CR | {
"author": "Jan Kara <jack@suse.cz>",
"date": "Fri, 27 Feb 2026 16:14:34 +0100",
"is_openbsd": false,
"thread_id": "yqxanlt3h4h2dwtpzgywsrzozdry3oe3c4yg22x6wqm2grntbu@pazi2ufzrwfv.mbox.gz"
} |
lkml_critique | lkml | Hey,
This reworks the simple_xattr infrastructure and adds support for
user.* extended attributes on sockets.
The simple_xattr subsystem currently uses an rbtree protected by a
reader-writer spinlock. This series replaces the rbtree with an
rhashtable giving O(1) average-case lookup with RCU-based lockless
reads. Thi... | null | null | null | [PATCH 00/14] xattr: rework simple xattrs and support user.*
xattrs on sockets | On Mon 16-02-26 14:32:03, Christian Brauner wrote:
Looks good. Feel free to add:
Reviewed-by: Jan Kara <jack@suse.cz>
Honza
--
Jan Kara <jack@suse.com>
SUSE Labs, CR | {
"author": "Jan Kara <jack@suse.cz>",
"date": "Fri, 27 Feb 2026 16:15:17 +0100",
"is_openbsd": false,
"thread_id": "yqxanlt3h4h2dwtpzgywsrzozdry3oe3c4yg22x6wqm2grntbu@pazi2ufzrwfv.mbox.gz"
} |
lkml_critique | lkml | Hey,
This reworks the simple_xattr infrastructure and adds support for
user.* extended attributes on sockets.
The simple_xattr subsystem currently uses an rbtree protected by a
reader-writer spinlock. This series replaces the rbtree with an
rhashtable giving O(1) average-case lookup with RCU-based lockless
reads. Thi... | null | null | null | [PATCH 00/14] xattr: rework simple xattrs and support user.*
xattrs on sockets | On Fri 27-02-26 16:09:15, Jan Kara wrote:
Ah, I've now found out rhashtable_free_and_destroy() can sleep and that's
likely the reason. OK. Feel free to add:
Reviewed-by: Jan Kara <jack@suse.cz>
Honza
--
Jan Kara <jack@suse.com>
SUSE Labs, CR | {
"author": "Jan Kara <jack@suse.cz>",
"date": "Fri, 27 Feb 2026 16:16:04 +0100",
"is_openbsd": false,
"thread_id": "yqxanlt3h4h2dwtpzgywsrzozdry3oe3c4yg22x6wqm2grntbu@pazi2ufzrwfv.mbox.gz"
} |
lkml_critique | lkml | Hey,
This reworks the simple_xattr infrastructure and adds support for
user.* extended attributes on sockets.
The simple_xattr subsystem currently uses an rbtree protected by a
reader-writer spinlock. This series replaces the rbtree with an
rhashtable giving O(1) average-case lookup with RCU-based lockless
reads. Thi... | null | null | null | [PATCH 00/14] xattr: rework simple xattrs and support user.*
xattrs on sockets | On Mon 16-02-26 14:32:04, Christian Brauner wrote:
Looks good. Feel free to add:
Reviewed-by: Jan Kara <jack@suse.cz>
Honza
--
Jan Kara <jack@suse.com>
SUSE Labs, CR | {
"author": "Jan Kara <jack@suse.cz>",
"date": "Fri, 27 Feb 2026 16:17:42 +0100",
"is_openbsd": false,
"thread_id": "yqxanlt3h4h2dwtpzgywsrzozdry3oe3c4yg22x6wqm2grntbu@pazi2ufzrwfv.mbox.gz"
} |
lkml_critique | lkml | Hey,
This reworks the simple_xattr infrastructure and adds support for
user.* extended attributes on sockets.
The simple_xattr subsystem currently uses an rbtree protected by a
reader-writer spinlock. This series replaces the rbtree with an
rhashtable giving O(1) average-case lookup with RCU-based lockless
reads. Thi... | null | null | null | [PATCH 00/14] xattr: rework simple xattrs and support user.*
xattrs on sockets | On Mon 16-02-26 14:32:05, Christian Brauner wrote:
Looks good. Feel free to add:
Reviewed-by: Jan Kara <jack@suse.cz>
Honza
--
Jan Kara <jack@suse.com>
SUSE Labs, CR | {
"author": "Jan Kara <jack@suse.cz>",
"date": "Fri, 27 Feb 2026 16:20:36 +0100",
"is_openbsd": false,
"thread_id": "yqxanlt3h4h2dwtpzgywsrzozdry3oe3c4yg22x6wqm2grntbu@pazi2ufzrwfv.mbox.gz"
} |
lkml_critique | lkml | Hey,
This reworks the simple_xattr infrastructure and adds support for
user.* extended attributes on sockets.
The simple_xattr subsystem currently uses an rbtree protected by a
reader-writer spinlock. This series replaces the rbtree with an
rhashtable giving O(1) average-case lookup with RCU-based lockless
reads. Thi... | null | null | null | [PATCH 00/14] xattr: rework simple xattrs and support user.*
xattrs on sockets | On Mon 16-02-26 14:32:06, Christian Brauner wrote:
Looks good. Feel free to add:
Reviewed-by: Jan Kara <jack@suse.cz>
Honza
--
Jan Kara <jack@suse.com>
SUSE Labs, CR | {
"author": "Jan Kara <jack@suse.cz>",
"date": "Fri, 27 Feb 2026 16:25:14 +0100",
"is_openbsd": false,
"thread_id": "yqxanlt3h4h2dwtpzgywsrzozdry3oe3c4yg22x6wqm2grntbu@pazi2ufzrwfv.mbox.gz"
} |
lkml_critique | lkml | Hey,
This reworks the simple_xattr infrastructure and adds support for
user.* extended attributes on sockets.
The simple_xattr subsystem currently uses an rbtree protected by a
reader-writer spinlock. This series replaces the rbtree with an
rhashtable giving O(1) average-case lookup with RCU-based lockless
reads. Thi... | null | null | null | [PATCH 00/14] xattr: rework simple xattrs and support user.*
xattrs on sockets | On Mon 16-02-26 14:32:07, Christian Brauner wrote:
OK. Feel free to add:
Reviewed-by: Jan Kara <jack@suse.cz>
Honza
--
Jan Kara <jack@suse.com>
SUSE Labs, CR | {
"author": "Jan Kara <jack@suse.cz>",
"date": "Fri, 27 Feb 2026 16:26:07 +0100",
"is_openbsd": false,
"thread_id": "yqxanlt3h4h2dwtpzgywsrzozdry3oe3c4yg22x6wqm2grntbu@pazi2ufzrwfv.mbox.gz"
} |
lkml_critique | lkml | Hey,
This reworks the simple_xattr infrastructure and adds support for
user.* extended attributes on sockets.
The simple_xattr subsystem currently uses an rbtree protected by a
reader-writer spinlock. This series replaces the rbtree with an
rhashtable giving O(1) average-case lookup with RCU-based lockless
reads. Thi... | null | null | null | [PATCH 00/14] xattr: rework simple xattrs and support user.*
xattrs on sockets | On Mon 16-02-26 14:32:08, Christian Brauner wrote:
Looks good. Feel free to add:
Reviewed-by: Jan Kara <jack@suse.cz>
Honza
--
Jan Kara <jack@suse.com>
SUSE Labs, CR | {
"author": "Jan Kara <jack@suse.cz>",
"date": "Fri, 27 Feb 2026 16:29:08 +0100",
"is_openbsd": false,
"thread_id": "yqxanlt3h4h2dwtpzgywsrzozdry3oe3c4yg22x6wqm2grntbu@pazi2ufzrwfv.mbox.gz"
} |
lkml_critique | lkml | Hey,
This reworks the simple_xattr infrastructure and adds support for
user.* extended attributes on sockets.
The simple_xattr subsystem currently uses an rbtree protected by a
reader-writer spinlock. This series replaces the rbtree with an
rhashtable giving O(1) average-case lookup with RCU-based lockless
reads. Thi... | null | null | null | [PATCH 00/14] xattr: rework simple xattrs and support user.*
xattrs on sockets | On Mon 16-02-26 14:32:09, Christian Brauner wrote:
Looks good. Feel free to add:
Reviewed-by: Jan Kara <jack@suse.cz>
Honza
--
Jan Kara <jack@suse.com>
SUSE Labs, CR | {
"author": "Jan Kara <jack@suse.cz>",
"date": "Fri, 27 Feb 2026 16:30:53 +0100",
"is_openbsd": false,
"thread_id": "yqxanlt3h4h2dwtpzgywsrzozdry3oe3c4yg22x6wqm2grntbu@pazi2ufzrwfv.mbox.gz"
} |
lkml_critique | lkml | Hey,
This reworks the simple_xattr infrastructure and adds support for
user.* extended attributes on sockets.
The simple_xattr subsystem currently uses an rbtree protected by a
reader-writer spinlock. This series replaces the rbtree with an
rhashtable giving O(1) average-case lookup with RCU-based lockless
reads. Thi... | null | null | null | [PATCH 00/14] xattr: rework simple xattrs and support user.*
xattrs on sockets | On Mon 16-02-26 14:32:10, Christian Brauner wrote:
Looks good. Feel free to add:
Reviewed-by: Jan Kara <jack@suse.cz>
Honza
--
Jan Kara <jack@suse.com>
SUSE Labs, CR | {
"author": "Jan Kara <jack@suse.cz>",
"date": "Fri, 27 Feb 2026 16:32:22 +0100",
"is_openbsd": false,
"thread_id": "yqxanlt3h4h2dwtpzgywsrzozdry3oe3c4yg22x6wqm2grntbu@pazi2ufzrwfv.mbox.gz"
} |
lkml_critique | lkml | The GEM MAC provides four read-only, clear-on-read LPI statistics
registers at offsets 0x270-0x27c:
GEM_RXLPI (0x270): RX LPI transition count (16-bit)
GEM_RXLPITIME (0x274): cumulative RX LPI time (24-bit)
GEM_TXLPI (0x278): TX LPI transition count (16-bit)
GEM_TXLPITIME (0x27c): cumulative TX LPI tim... | null | null | null | [PATCH net-next v5 1/5] net: cadence: macb: add EEE LPI statistics counters | Set MACB_CAPS_EEE for the Raspberry Pi 5 RP1 southbridge
(Cadence GEM_GXL rev 0x00070109 paired with BCM54213PE PHY).
EEE has been verified on RP1 hardware: the LPI counter registers
at 0x270-0x27c return valid data, the TXLPIEN bit in NCR (bit 19)
controls LPI transmission correctly, and ethtool --show-eee reports
th... | {
"author": "Nicolai Buchwitz <nb@tipi-net.de>",
"date": "Fri, 27 Feb 2026 16:06:09 +0100",
"is_openbsd": false,
"thread_id": "20260227150610.242215-2-nb@tipi-net.de.mbox.gz"
} |
lkml_critique | lkml | The GEM MAC provides four read-only, clear-on-read LPI statistics
registers at offsets 0x270-0x27c:
GEM_RXLPI (0x270): RX LPI transition count (16-bit)
GEM_RXLPITIME (0x274): cumulative RX LPI time (24-bit)
GEM_TXLPI (0x278): TX LPI transition count (16-bit)
GEM_TXLPITIME (0x27c): cumulative TX LPI tim... | null | null | null | [PATCH net-next v5 1/5] net: cadence: macb: add EEE LPI statistics counters | Add Energy Efficient Ethernet (IEEE 802.3az) support to the Cadence GEM
(macb) driver using phylink's managed EEE framework. The GEM MAC has
hardware LPI registers but no built-in idle timer, so the driver
implements software-managed TX LPI using a delayed_work timer while
delegating EEE negotiation and ethtool state t... | {
"author": "Nicolai Buchwitz <nb@tipi-net.de>",
"date": "Fri, 27 Feb 2026 16:06:05 +0100",
"is_openbsd": false,
"thread_id": "20260227150610.242215-2-nb@tipi-net.de.mbox.gz"
} |
lkml_critique | lkml | The GEM MAC provides four read-only, clear-on-read LPI statistics
registers at offsets 0x270-0x27c:
GEM_RXLPI (0x270): RX LPI transition count (16-bit)
GEM_RXLPITIME (0x274): cumulative RX LPI time (24-bit)
GEM_TXLPI (0x278): TX LPI transition count (16-bit)
GEM_TXLPITIME (0x27c): cumulative TX LPI tim... | null | null | null | [PATCH net-next v5 1/5] net: cadence: macb: add EEE LPI statistics counters | Implement get_eee and set_eee ethtool ops for GEM as simple passthroughs
to phylink_ethtool_get_eee() and phylink_ethtool_set_eee().
No MACB_CAPS_EEE guard is needed: phylink returns -EOPNOTSUPP from both
ops when mac_supports_eee is false, which is the case when
lpi_capabilities and lpi_interfaces are not populated. ... | {
"author": "Nicolai Buchwitz <nb@tipi-net.de>",
"date": "Fri, 27 Feb 2026 16:06:08 +0100",
"is_openbsd": false,
"thread_id": "20260227150610.242215-2-nb@tipi-net.de.mbox.gz"
} |
lkml_critique | lkml | The GEM MAC provides four read-only, clear-on-read LPI statistics
registers at offsets 0x270-0x27c:
GEM_RXLPI (0x270): RX LPI transition count (16-bit)
GEM_RXLPITIME (0x274): cumulative RX LPI time (24-bit)
GEM_TXLPI (0x278): TX LPI transition count (16-bit)
GEM_TXLPITIME (0x27c): cumulative TX LPI tim... | null | null | null | [PATCH net-next v5 1/5] net: cadence: macb: add EEE LPI statistics counters | The GEM MAC has hardware LPI registers (NCR bit 19: TXLPIEN) but no
built-in idle timer, so asserting TXLPIEN blocks all TX immediately
with no automatic wake. A software idle timer is required, as noted
in Microchip documentation (section 40.6.19): "It is best to use
firmware to control LPI."
Implement phylink manage... | {
"author": "Nicolai Buchwitz <nb@tipi-net.de>",
"date": "Fri, 27 Feb 2026 16:06:07 +0100",
"is_openbsd": false,
"thread_id": "20260227150610.242215-2-nb@tipi-net.de.mbox.gz"
} |
lkml_critique | lkml | The GEM MAC provides four read-only, clear-on-read LPI statistics
registers at offsets 0x270-0x27c:
GEM_RXLPI (0x270): RX LPI transition count (16-bit)
GEM_RXLPITIME (0x274): cumulative RX LPI time (24-bit)
GEM_TXLPI (0x278): TX LPI transition count (16-bit)
GEM_TXLPITIME (0x27c): cumulative TX LPI tim... | null | null | null | [PATCH net-next v5 1/5] net: cadence: macb: add EEE LPI statistics counters | Set MACB_CAPS_EEE for the Mobileye EyeQ5 GEM instance. EEE has been
verified on EyeQ5 hardware using a loopback setup with ethtool
--show-eee confirming EEE active on both ends at 100baseT/Full and
1000baseT/Full.
Tested-by: Théo Lebrun <theo.lebrun@bootlin.com>
Signed-off-by: Nicolai Buchwitz <nb@tipi-net.de>
---
dr... | {
"author": "Nicolai Buchwitz <nb@tipi-net.de>",
"date": "Fri, 27 Feb 2026 16:06:10 +0100",
"is_openbsd": false,
"thread_id": "20260227150610.242215-2-nb@tipi-net.de.mbox.gz"
} |
lkml_critique | lkml | When large folio is enabled and the initial folio offset exceeds
PAGE_SIZE, e.g. the position resides in the second page of a large
folio, after the folio copying the offset (in the page) won't be updated
to 0 even though the expected range is successfully copied until the end
of the folio. In this case fuse_fill_writ... | null | null | null | [PATCH v3] fuse: fix premature writetrhough request for large folio | On Thu, 15 Jan 2026 at 03:36, Jingbo Xu <jefflexu@linux.alibaba.com> wrote:
Applied, thanks.
Miklos | {
"author": "Miklos Szeredi <miklos@szeredi.hu>",
"date": "Fri, 27 Feb 2026 16:23:35 +0100",
"is_openbsd": false,
"thread_id": "CAJfpegts6NiEokGSC7t+bXKHWHadYhxjYZDZ0+PabNSTnWVDLg@mail.gmail.com.mbox.gz"
} |
lkml_critique | lkml | The series trys to add USB2 PHY support for SpacemiT K3 SoC,
while patch [2/3] implement a disconnect function which is
needed during next connection.
No DTS part has been inclueded in this series, instead I plan
to submit while adding USB host support.
Signed-off-by: Yixun Lan <dlan@kernel.org>
---
Changes in v2:
- ... | null | null | null | [PATCH v2 0/3] phy: spacemit: Add USB2 PHY support for K3 SoC | Introduce a compatible string for the USB2 PHY in SpacemiT K3 SoC. The IP
of USB2 PHY mostly shares the same functionalities with K1 SoC, while has
some register layout changes.
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Signed-off-by: Yixun Lan <dlan@kernel.org>
---
Documentation/devicetree... | {
"author": "Yixun Lan <dlan@kernel.org>",
"date": "Sat, 14 Feb 2026 20:29:14 +0800",
"is_openbsd": false,
"thread_id": "aaGxX_3FXjM1LT6y@vaman.mbox.gz"
} |
lkml_critique | lkml | The series trys to add USB2 PHY support for SpacemiT K3 SoC,
while patch [2/3] implement a disconnect function which is
needed during next connection.
No DTS part has been inclueded in this series, instead I plan
to submit while adding USB host support.
Signed-off-by: Yixun Lan <dlan@kernel.org>
---
Changes in v2:
- ... | null | null | null | [PATCH v2 0/3] phy: spacemit: Add USB2 PHY support for K3 SoC | A disconnect status BIT of USB2 PHY need to be cleared, otherwise
it will fail to work properly during next connection when devices
connect to roothub directly.
Fixes: fe4bc1a08638 ("phy: spacemit: support K1 USB2.0 PHY controller")
Signed-off-by: Yixun Lan <dlan@kernel.org>
---
drivers/phy/spacemit/phy-k1-usb2.c | 1... | {
"author": "Yixun Lan <dlan@kernel.org>",
"date": "Sat, 14 Feb 2026 20:29:15 +0800",
"is_openbsd": false,
"thread_id": "aaGxX_3FXjM1LT6y@vaman.mbox.gz"
} |
lkml_critique | lkml | The series trys to add USB2 PHY support for SpacemiT K3 SoC,
while patch [2/3] implement a disconnect function which is
needed during next connection.
No DTS part has been inclueded in this series, instead I plan
to submit while adding USB host support.
Signed-off-by: Yixun Lan <dlan@kernel.org>
---
Changes in v2:
- ... | null | null | null | [PATCH v2 0/3] phy: spacemit: Add USB2 PHY support for K3 SoC | Add USB2 PHY support for SpacemiT K3 SoC.
Register layout of handling USB disconnect operation has been changed,
So introducing a platform data to distinguish the different SoCs.
Signed-off-by: Yixun Lan <dlan@kernel.org>
---
drivers/phy/spacemit/phy-k1-usb2.c | 34 +++++++++++++++++++++++++++++-----
1 file changed,... | {
"author": "Yixun Lan <dlan@kernel.org>",
"date": "Sat, 14 Feb 2026 20:29:16 +0800",
"is_openbsd": false,
"thread_id": "aaGxX_3FXjM1LT6y@vaman.mbox.gz"
} |
lkml_critique | lkml | The series trys to add USB2 PHY support for SpacemiT K3 SoC,
while patch [2/3] implement a disconnect function which is
needed during next connection.
No DTS part has been inclueded in this series, instead I plan
to submit while adding USB host support.
Signed-off-by: Yixun Lan <dlan@kernel.org>
---
Changes in v2:
- ... | null | null | null | [PATCH v2 0/3] phy: spacemit: Add USB2 PHY support for K3 SoC | Hello Yixun,
On Sat, Feb 14, 2026 at 08:29:15PM +0800, Yixun Lan wrote:
Please align function arguments to the open parenthesis.
Since we are in the merge window, it is likely that new features will
not be picked up at this stage.
But this seems to be a fix for existing SpacemiT K1 support, currently
in the linux-p... | {
"author": "Vladimir Oltean <olteanv@gmail.com>",
"date": "Mon, 16 Feb 2026 11:01:12 +0200",
"is_openbsd": false,
"thread_id": "aaGxX_3FXjM1LT6y@vaman.mbox.gz"
} |
lkml_critique | lkml | The series trys to add USB2 PHY support for SpacemiT K3 SoC,
while patch [2/3] implement a disconnect function which is
needed during next connection.
No DTS part has been inclueded in this series, instead I plan
to submit while adding USB host support.
Signed-off-by: Yixun Lan <dlan@kernel.org>
---
Changes in v2:
- ... | null | null | null | [PATCH v2 0/3] phy: spacemit: Add USB2 PHY support for K3 SoC | On 11:01 Mon 16 Feb , Vladimir Oltean wrote:
Ok
Sure, no problem and I expect this is normal..
Ok, done
http://lore.kernel.org/r/20260216152653.25244-1-dlan@kernel.org
will do once new -rc1 is tagged
--
Yixun Lan (dlan) | {
"author": "Yixun Lan <dlan@gentoo.org>",
"date": "Mon, 16 Feb 2026 23:29:54 +0800",
"is_openbsd": false,
"thread_id": "aaGxX_3FXjM1LT6y@vaman.mbox.gz"
} |
lkml_critique | lkml | After initializing a field in an initializer macro, create a variable
holding a reference that points at that field. The type is either
`Pin<&mut T>` or `&mut T` depending on the field's structural pinning
kind.
Link: https://github.com/Rust-for-Linux/pin-init/pull/83/commits/0f658594c39398f58cd5cb99a8141e370e225e74
S... | null | null | null | [PATCH] rust: pin-init: add references to previously initialized fields | On Fri Sep 5, 2025 at 4:00 PM CEST, Benno Lossin wrote:
I forgot to test with the right configuration and found some errors with
existing code. Here are their fixes. If I don't need to re-send, I will
add them on apply (if you want a v2, let me know).
---
Cheers,
Benno
diff --git a/rust/kernel/devres.rs b/rust/kerne... | {
"author": "\"Benno Lossin\" <lossin@kernel.org>",
"date": "Fri, 05 Sep 2025 19:18:25 +0200",
"is_openbsd": false,
"thread_id": "DGPU3530XZA3.3SY27R9VIC9Y9@kernel.org.mbox.gz"
} |
lkml_critique | lkml | After initializing a field in an initializer macro, create a variable
holding a reference that points at that field. The type is either
`Pin<&mut T>` or `&mut T` depending on the field's structural pinning
kind.
Link: https://github.com/Rust-for-Linux/pin-init/pull/83/commits/0f658594c39398f58cd5cb99a8141e370e225e74
S... | null | null | null | [PATCH] rust: pin-init: add references to previously initialized fields | On Fri, Sep 05, 2025 at 04:00:46PM +0200, Benno Lossin wrote:
It's hard to review because of lack of examples. Could you or Danilo
share some sample usages? Thanks!
Regards,
Boqun
[...] | {
"author": "Boqun Feng <boqun.feng@gmail.com>",
"date": "Fri, 5 Sep 2025 10:21:50 -0700",
"is_openbsd": false,
"thread_id": "DGPU3530XZA3.3SY27R9VIC9Y9@kernel.org.mbox.gz"
} |
lkml_critique | lkml | After initializing a field in an initializer macro, create a variable
holding a reference that points at that field. The type is either
`Pin<&mut T>` or `&mut T` depending on the field's structural pinning
kind.
Link: https://github.com/Rust-for-Linux/pin-init/pull/83/commits/0f658594c39398f58cd5cb99a8141e370e225e74
S... | null | null | null | [PATCH] rust: pin-init: add references to previously initialized fields | On Fri, Sep 05, 2025 at 07:18:25PM +0200, Benno Lossin wrote:
[...]
Ok, this example is good enough for me to express the concern here: the
variable shadowing behavior seems not straightforward (maybe because in
normal Rust initalization expression, no binding is created for
previous variables, neither do we have a `l... | {
"author": "Boqun Feng <boqun.feng@gmail.com>",
"date": "Fri, 5 Sep 2025 10:44:23 -0700",
"is_openbsd": false,
"thread_id": "DGPU3530XZA3.3SY27R9VIC9Y9@kernel.org.mbox.gz"
} |
lkml_critique | lkml | After initializing a field in an initializer macro, create a variable
holding a reference that points at that field. The type is either
`Pin<&mut T>` or `&mut T` depending on the field's structural pinning
kind.
Link: https://github.com/Rust-for-Linux/pin-init/pull/83/commits/0f658594c39398f58cd5cb99a8141e370e225e74
S... | null | null | null | [PATCH] rust: pin-init: add references to previously initialized fields | (Cc: Alex)
On Fri Sep 5, 2025 at 7:21 PM CEST, Boqun Feng wrote:
Sure, here's an example. Eventually, it's going to be a bit more complicated,
but basically that's it.
#[pin_data(PinnedDrop)]
pub(crate) struct Gpu {
spec: Spec,
bar: Arc<Devres<Bar0>>,
sysmem_flush: SysmemFlush,
gsp_falcon: Falc... | {
"author": "\"Danilo Krummrich\" <dakr@kernel.org>",
"date": "Fri, 05 Sep 2025 20:38:11 +0200",
"is_openbsd": false,
"thread_id": "DGPU3530XZA3.3SY27R9VIC9Y9@kernel.org.mbox.gz"
} |
lkml_critique | lkml | After initializing a field in an initializer macro, create a variable
holding a reference that points at that field. The type is either
`Pin<&mut T>` or `&mut T` depending on the field's structural pinning
kind.
Link: https://github.com/Rust-for-Linux/pin-init/pull/83/commits/0f658594c39398f58cd5cb99a8141e370e225e74
S... | null | null | null | [PATCH] rust: pin-init: add references to previously initialized fields | On Fri Sep 5, 2025 at 7:44 PM CEST, Boqun Feng wrote:
Can you please clarify the example? I'm a bit confused that this is not a field
of Self, so currently this can just be written as:
try_pin_init!(Self {
b: a,
c: a.into,
})
Of course assuming that a is Clone, as the code above does as well.
So, if we ar... | {
"author": "\"Danilo Krummrich\" <dakr@kernel.org>",
"date": "Sat, 06 Sep 2025 12:52:22 +0200",
"is_openbsd": false,
"thread_id": "DGPU3530XZA3.3SY27R9VIC9Y9@kernel.org.mbox.gz"
} |
lkml_critique | lkml | After initializing a field in an initializer macro, create a variable
holding a reference that points at that field. The type is either
`Pin<&mut T>` or `&mut T` depending on the field's structural pinning
kind.
Link: https://github.com/Rust-for-Linux/pin-init/pull/83/commits/0f658594c39398f58cd5cb99a8141e370e225e74
S... | null | null | null | [PATCH] rust: pin-init: add references to previously initialized fields | Hi Benno,
kernel test robot noticed the following build errors:
[auto build test ERROR on 8f5ae30d69d7543eee0d70083daf4de8fe15d585]
url: https://github.com/intel-lab-lkp/linux/commits/Benno-Lossin/rust-pin-init-add-references-to-previously-initialized-fields/20250905-220242
base: 8f5ae30d69d7543eee0d70083daf4de... | {
"author": "kernel test robot <lkp@intel.com>",
"date": "Sat, 6 Sep 2025 22:23:15 +0800",
"is_openbsd": false,
"thread_id": "DGPU3530XZA3.3SY27R9VIC9Y9@kernel.org.mbox.gz"
} |
lkml_critique | lkml | After initializing a field in an initializer macro, create a variable
holding a reference that points at that field. The type is either
`Pin<&mut T>` or `&mut T` depending on the field's structural pinning
kind.
Link: https://github.com/Rust-for-Linux/pin-init/pull/83/commits/0f658594c39398f58cd5cb99a8141e370e225e74
S... | null | null | null | [PATCH] rust: pin-init: add references to previously initialized fields | On Sat, Sep 06, 2025 at 12:52:22PM +0200, Danilo Krummrich wrote:
Oh, I could have been more clear: `a` is a field of `Self`, and the
`let` part initalizes it.
I'm not that concerned to block this, but it does look to me like we are
inventing a new way (and even a different syntax because normal Rust
initialization ... | {
"author": "Boqun Feng <boqun.feng@gmail.com>",
"date": "Sat, 6 Sep 2025 18:57:04 -0700",
"is_openbsd": false,
"thread_id": "DGPU3530XZA3.3SY27R9VIC9Y9@kernel.org.mbox.gz"
} |
lkml_critique | lkml | After initializing a field in an initializer macro, create a variable
holding a reference that points at that field. The type is either
`Pin<&mut T>` or `&mut T` depending on the field's structural pinning
kind.
Link: https://github.com/Rust-for-Linux/pin-init/pull/83/commits/0f658594c39398f58cd5cb99a8141e370e225e74
S... | null | null | null | [PATCH] rust: pin-init: add references to previously initialized fields | On Sat, Sep 06, 2025 at 06:57:04PM -0700, Boqun Feng wrote:
Another idea is using `&this`:
try_pin_init!(&this in Self {
a, // Initialize the field only.
b <- b, // Initialize the field only.
c: a.into(), // That's the "original" `a`.
d <- D::new(this->b), ... | {
"author": "Boqun Feng <boqun.feng@gmail.com>",
"date": "Sat, 6 Sep 2025 19:07:05 -0700",
"is_openbsd": false,
"thread_id": "DGPU3530XZA3.3SY27R9VIC9Y9@kernel.org.mbox.gz"
} |
lkml_critique | lkml | After initializing a field in an initializer macro, create a variable
holding a reference that points at that field. The type is either
`Pin<&mut T>` or `&mut T` depending on the field's structural pinning
kind.
Link: https://github.com/Rust-for-Linux/pin-init/pull/83/commits/0f658594c39398f58cd5cb99a8141e370e225e74
S... | null | null | null | [PATCH] rust: pin-init: add references to previously initialized fields | On Sun Sep 7, 2025 at 4:07 AM CEST, Boqun Feng wrote:
The main issue with new syntax is the difficulty of implementing it. The
let one is fine, but it's pretty jarring & doesn't get formatted by
rustfmt (which I want to eventually have). Using `this` does look better
IMO, but it's near impossible to implement using de... | {
"author": "\"Benno Lossin\" <lossin@kernel.org>",
"date": "Sun, 07 Sep 2025 10:41:48 +0200",
"is_openbsd": false,
"thread_id": "DGPU3530XZA3.3SY27R9VIC9Y9@kernel.org.mbox.gz"
} |
lkml_critique | lkml | After initializing a field in an initializer macro, create a variable
holding a reference that points at that field. The type is either
`Pin<&mut T>` or `&mut T` depending on the field's structural pinning
kind.
Link: https://github.com/Rust-for-Linux/pin-init/pull/83/commits/0f658594c39398f58cd5cb99a8141e370e225e74
S... | null | null | null | [PATCH] rust: pin-init: add references to previously initialized fields | On Sun Sep 7, 2025 at 10:41 AM CEST, Benno Lossin wrote:
I also thought about reusing `this`, but I think we should not reuse it. We
still need it to get pointers to uninitialized fields.
Surely, we could say that we provide this.as_ptr() to get the NonNull `this`
is currently defined to be and otherwise make it expo... | {
"author": "\"Danilo Krummrich\" <dakr@kernel.org>",
"date": "Sun, 07 Sep 2025 19:29:45 +0200",
"is_openbsd": false,
"thread_id": "DGPU3530XZA3.3SY27R9VIC9Y9@kernel.org.mbox.gz"
} |
lkml_critique | lkml | After initializing a field in an initializer macro, create a variable
holding a reference that points at that field. The type is either
`Pin<&mut T>` or `&mut T` depending on the field's structural pinning
kind.
Link: https://github.com/Rust-for-Linux/pin-init/pull/83/commits/0f658594c39398f58cd5cb99a8141e370e225e74
S... | null | null | null | [PATCH] rust: pin-init: add references to previously initialized fields | On Sun Sep 7, 2025 at 7:29 PM CEST, Danilo Krummrich wrote:
I have some ideas of changing the syntax to be more closure-esque:
init!(|this| -> Result<MyStruct, Error> {
let x = 42;
MyStruct {
x,
}
})
There we could add another parameter, that would then serve this
purpose.... | {
"author": "\"Benno Lossin\" <lossin@kernel.org>",
"date": "Sun, 07 Sep 2025 23:06:21 +0200",
"is_openbsd": false,
"thread_id": "DGPU3530XZA3.3SY27R9VIC9Y9@kernel.org.mbox.gz"
} |
lkml_critique | lkml | After initializing a field in an initializer macro, create a variable
holding a reference that points at that field. The type is either
`Pin<&mut T>` or `&mut T` depending on the field's structural pinning
kind.
Link: https://github.com/Rust-for-Linux/pin-init/pull/83/commits/0f658594c39398f58cd5cb99a8141e370e225e74
S... | null | null | null | [PATCH] rust: pin-init: add references to previously initialized fields | On Sun Sep 7, 2025 at 11:06 PM CEST, Benno Lossin wrote:
I think that's a pretty good idea, but the part that I think is a little bit
confusing remains: `this` will need to have different fields depending on where
it's accessed.
Yeah, it's not great, but given that it's a custom syntax it also does not
create wrong ... | {
"author": "\"Danilo Krummrich\" <dakr@kernel.org>",
"date": "Sun, 07 Sep 2025 23:39:13 +0200",
"is_openbsd": false,
"thread_id": "DGPU3530XZA3.3SY27R9VIC9Y9@kernel.org.mbox.gz"
} |
lkml_critique | lkml | After initializing a field in an initializer macro, create a variable
holding a reference that points at that field. The type is either
`Pin<&mut T>` or `&mut T` depending on the field's structural pinning
kind.
Link: https://github.com/Rust-for-Linux/pin-init/pull/83/commits/0f658594c39398f58cd5cb99a8141e370e225e74
S... | null | null | null | [PATCH] rust: pin-init: add references to previously initialized fields | On Sun Sep 7, 2025 at 11:39 PM CEST, Danilo Krummrich wrote:
Yeah (that's also the main issue with the macro implementation).
I'd say it looks like combining the `<-` operation already used by the
`init!` macro & a `let` binding. Thus introducing a local variable
that's (pin) initialized in-place. Not a field of the... | {
"author": "\"Benno Lossin\" <lossin@kernel.org>",
"date": "Mon, 08 Sep 2025 00:51:02 +0200",
"is_openbsd": false,
"thread_id": "DGPU3530XZA3.3SY27R9VIC9Y9@kernel.org.mbox.gz"
} |
lkml_critique | lkml | After initializing a field in an initializer macro, create a variable
holding a reference that points at that field. The type is either
`Pin<&mut T>` or `&mut T` depending on the field's structural pinning
kind.
Link: https://github.com/Rust-for-Linux/pin-init/pull/83/commits/0f658594c39398f58cd5cb99a8141e370e225e74
S... | null | null | null | [PATCH] rust: pin-init: add references to previously initialized fields | On Mon Sep 8, 2025 at 12:51 AM CEST, Benno Lossin wrote:
It may be a bit verbose is some cases, but it makes things pretty obvious, so
LGTM.
How about just #[bind] or #[access]? | {
"author": "\"Danilo Krummrich\" <dakr@kernel.org>",
"date": "Mon, 08 Sep 2025 01:33:26 +0200",
"is_openbsd": false,
"thread_id": "DGPU3530XZA3.3SY27R9VIC9Y9@kernel.org.mbox.gz"
} |
lkml_critique | lkml | After initializing a field in an initializer macro, create a variable
holding a reference that points at that field. The type is either
`Pin<&mut T>` or `&mut T` depending on the field's structural pinning
kind.
Link: https://github.com/Rust-for-Linux/pin-init/pull/83/commits/0f658594c39398f58cd5cb99a8141e370e225e74
S... | null | null | null | [PATCH] rust: pin-init: add references to previously initialized fields | On Mon, Sep 08, 2025 at 01:33:26AM +0200, Danilo Krummrich wrote:
#[shadow] or #[maybe_rebind] ? Or #[pin_ref], the last one is clear
about the purpose.
Regards,
Boqun | {
"author": "Boqun Feng <boqun.feng@gmail.com>",
"date": "Sun, 7 Sep 2025 19:08:29 -0700",
"is_openbsd": false,
"thread_id": "DGPU3530XZA3.3SY27R9VIC9Y9@kernel.org.mbox.gz"
} |
lkml_critique | lkml | After initializing a field in an initializer macro, create a variable
holding a reference that points at that field. The type is either
`Pin<&mut T>` or `&mut T` depending on the field's structural pinning
kind.
Link: https://github.com/Rust-for-Linux/pin-init/pull/83/commits/0f658594c39398f58cd5cb99a8141e370e225e74
S... | null | null | null | [PATCH] rust: pin-init: add references to previously initialized fields | On Mon Sep 8, 2025 at 4:08 AM CEST, Boqun Feng wrote:
I like `#[bind]`.
Hmm in `init!` it's never pinned.
---
Cheers,
Benno | {
"author": "\"Benno Lossin\" <lossin@kernel.org>",
"date": "Mon, 08 Sep 2025 10:27:40 +0200",
"is_openbsd": false,
"thread_id": "DGPU3530XZA3.3SY27R9VIC9Y9@kernel.org.mbox.gz"
} |
lkml_critique | lkml | After initializing a field in an initializer macro, create a variable
holding a reference that points at that field. The type is either
`Pin<&mut T>` or `&mut T` depending on the field's structural pinning
kind.
Link: https://github.com/Rust-for-Linux/pin-init/pull/83/commits/0f658594c39398f58cd5cb99a8141e370e225e74
S... | null | null | null | [PATCH] rust: pin-init: add references to previously initialized fields | On Mon Sep 8, 2025 at 10:27 AM CEST, Benno Lossin wrote:
I thought about #[shadow] as well, but it is not really accurate I think, as we
might not shadow anything. #[maybe_rebind] sounds a bit like it conditionally
rebinds, as in "it may not do anything", but it always binds.
So, I think it should one clear instructi... | {
"author": "\"Danilo Krummrich\" <dakr@kernel.org>",
"date": "Mon, 08 Sep 2025 10:57:36 +0200",
"is_openbsd": false,
"thread_id": "DGPU3530XZA3.3SY27R9VIC9Y9@kernel.org.mbox.gz"
} |
lkml_critique | lkml | After initializing a field in an initializer macro, create a variable
holding a reference that points at that field. The type is either
`Pin<&mut T>` or `&mut T` depending on the field's structural pinning
kind.
Link: https://github.com/Rust-for-Linux/pin-init/pull/83/commits/0f658594c39398f58cd5cb99a8141e370e225e74
S... | null | null | null | [PATCH] rust: pin-init: add references to previously initialized fields | On Mon, Sep 08, 2025 at 10:57:36AM +0200, Danilo Krummrich wrote:
In that sense I think `#[let]` is best? Because it indicates this field
initialization works as a `let`-statement (in term of creating a new
binding), of course I don't have strong ojections against other options.
Regards,
Boqun | {
"author": "Boqun Feng <boqun.feng@gmail.com>",
"date": "Mon, 8 Sep 2025 12:38:04 -0700",
"is_openbsd": false,
"thread_id": "DGPU3530XZA3.3SY27R9VIC9Y9@kernel.org.mbox.gz"
} |
lkml_critique | lkml | After initializing a field in an initializer macro, create a variable
holding a reference that points at that field. The type is either
`Pin<&mut T>` or `&mut T` depending on the field's structural pinning
kind.
Link: https://github.com/Rust-for-Linux/pin-init/pull/83/commits/0f658594c39398f58cd5cb99a8141e370e225e74
S... | null | null | null | [PATCH] rust: pin-init: add references to previously initialized fields | On Mon Sep 8, 2025 at 9:38 PM CEST, Boqun Feng wrote:
Ultimately I decided to go with `#[bind]`, since I felt like `#[let]`
might be confused with just having a let statement (ie replacing the
assignment with a let binding).
`#[bind]` also might be confused with some device binding I guess, but
we can rename it's too... | {
"author": "\"Benno Lossin\" <lossin@kernel.org>",
"date": "Wed, 10 Sep 2025 12:12:23 +0200",
"is_openbsd": false,
"thread_id": "DGPU3530XZA3.3SY27R9VIC9Y9@kernel.org.mbox.gz"
} |
lkml_critique | lkml | After initializing a field in an initializer macro, create a variable
holding a reference that points at that field. The type is either
`Pin<&mut T>` or `&mut T` depending on the field's structural pinning
kind.
Link: https://github.com/Rust-for-Linux/pin-init/pull/83/commits/0f658594c39398f58cd5cb99a8141e370e225e74
S... | null | null | null | [PATCH] rust: pin-init: add references to previously initialized fields | On Fri Sep 5, 2025 at 4:00 PM CEST, Benno Lossin wrote:
Applied to pin-init-next, thanks everyone!
Included the fixes to devres & rust_driver_pci.
---
Cheers,
Benno | {
"author": "\"Benno Lossin\" <lossin@kernel.org>",
"date": "Thu, 11 Sep 2025 23:35:53 +0200",
"is_openbsd": false,
"thread_id": "DGPU3530XZA3.3SY27R9VIC9Y9@kernel.org.mbox.gz"
} |
lkml_critique | lkml | After initializing a field in an initializer macro, create a variable
holding a reference that points at that field. The type is either
`Pin<&mut T>` or `&mut T` depending on the field's structural pinning
kind.
Link: https://github.com/Rust-for-Linux/pin-init/pull/83/commits/0f658594c39398f58cd5cb99a8141e370e225e74
S... | null | null | null | [PATCH] rust: pin-init: add references to previously initialized fields | On Fri, Sep 05, 2025 at 04:00:46PM +0200, Benno Lossin wrote:
just as a heads up: creating references broke part of the agx firmware
init structs which uses a `#[repr(C, packed)]` struct as field in
another struct. This fails with
| error[E0793]: reference to packed field is unaligned
| --> ../drivers/gpu/drm/asah... | {
"author": "Janne Grunau <j@jannau.net>",
"date": "Wed, 3 Dec 2025 23:05:16 +0100",
"is_openbsd": false,
"thread_id": "DGPU3530XZA3.3SY27R9VIC9Y9@kernel.org.mbox.gz"
} |
lkml_critique | lkml | After initializing a field in an initializer macro, create a variable
holding a reference that points at that field. The type is either
`Pin<&mut T>` or `&mut T` depending on the field's structural pinning
kind.
Link: https://github.com/Rust-for-Linux/pin-init/pull/83/commits/0f658594c39398f58cd5cb99a8141e370e225e74
S... | null | null | null | [PATCH] rust: pin-init: add references to previously initialized fields | On Wed Dec 3, 2025 at 11:05 PM CET, Janne Grunau wrote:
Thanks for the report, I expected the latter kind of error, but was not
aware of the packed struct issue. If anyone needs a proper workaround
from pin-init, let me know.
Cheers,
Benno | {
"author": "\"Benno Lossin\" <lossin@kernel.org>",
"date": "Sat, 06 Dec 2025 09:23:08 +0100",
"is_openbsd": false,
"thread_id": "DGPU3530XZA3.3SY27R9VIC9Y9@kernel.org.mbox.gz"
} |
lkml_critique | lkml | After initializing a field in an initializer macro, create a variable
holding a reference that points at that field. The type is either
`Pin<&mut T>` or `&mut T` depending on the field's structural pinning
kind.
Link: https://github.com/Rust-for-Linux/pin-init/pull/83/commits/0f658594c39398f58cd5cb99a8141e370e225e74
S... | null | null | null | [PATCH] rust: pin-init: add references to previously initialized fields | On Sat, Dec 06, 2025 at 09:23:08AM +0100, Benno Lossin wrote:
I spoke too soon. The packed struct issue is also present in the capture
driver for Macbook microphones (aop_audio). Working around this issue
there is less obvious and more effort. I think it might be enough to use
unaligned u32 / u64 types already present... | {
"author": "Janne Grunau <j@jannau.net>",
"date": "Sat, 6 Dec 2025 18:02:14 +0100",
"is_openbsd": false,
"thread_id": "DGPU3530XZA3.3SY27R9VIC9Y9@kernel.org.mbox.gz"
} |
lkml_critique | lkml | After initializing a field in an initializer macro, create a variable
holding a reference that points at that field. The type is either
`Pin<&mut T>` or `&mut T` depending on the field's structural pinning
kind.
Link: https://github.com/Rust-for-Linux/pin-init/pull/83/commits/0f658594c39398f58cd5cb99a8141e370e225e74
S... | null | null | null | [PATCH] rust: pin-init: add references to previously initialized fields | On Sat Dec 6, 2025 at 6:02 PM CET, Janne Grunau wrote:
FYI, I am merging a workaround this cycle, see [1]. Gary had a good idea
for a future patch series which I am tracking in [2].
Cheers,
Benno
[1]: https://lore.kernel.org/all/20260111122554.2662175-14-lossin@kernel.org
[2]: https://github.com/Rust-for-Linux/pin-i... | {
"author": "\"Benno Lossin\" <lossin@kernel.org>",
"date": "Sun, 11 Jan 2026 18:06:34 +0100",
"is_openbsd": false,
"thread_id": "DGPU3530XZA3.3SY27R9VIC9Y9@kernel.org.mbox.gz"
} |
lkml_critique | lkml | After initializing a field in an initializer macro, create a variable
holding a reference that points at that field. The type is either
`Pin<&mut T>` or `&mut T` depending on the field's structural pinning
kind.
Link: https://github.com/Rust-for-Linux/pin-init/pull/83/commits/0f658594c39398f58cd5cb99a8141e370e225e74
S... | null | null | null | [PATCH] rust: pin-init: add references to previously initialized fields | On Sun Jan 11, 2026 at 6:06 PM CET, Benno Lossin wrote:
Update on this situation, we have a problem: packed struct and the
current version of pin-init are unsound, so I'll sadly have to remove
the current workaround attribute. That is because the `[Pin]Init` trait
requires an aligned pointer as the input. Fixing this ... | {
"author": "\"Benno Lossin\" <lossin@kernel.org>",
"date": "Fri, 27 Feb 2026 16:02:43 +0100",
"is_openbsd": false,
"thread_id": "DGPU3530XZA3.3SY27R9VIC9Y9@kernel.org.mbox.gz"
} |
lkml_critique | lkml |
[ with 6.18 being an LTS release, it might be a good time for this ]
The introduction of PREEMPT_LAZY was for multiple reasons:
- PREEMPT_RT suffered from over-scheduling, hurting performance compared to
!PREEMPT_RT.
- the introduction of (more) features that rely on preemption; like
folio_zero_user() w... | null | null | null | [PATCH] sched: Further restrict the preemption modes | On Fri, 19 Dec 2025 11:15:02 +0100
Peter Zijlstra <peterz@infradead.org> wrote:
I think you can just make this:
default PREEMPT_LAZY
and remove the PREEMPT_NONE.
As PREEMPT_NONE now depends on ARCH_NO_PREEMPT and all the other options
depend on !ARCH_NO_PREEMPT, the default will be PREEMPT_LAZY if it's
available,... | {
"author": "Steven Rostedt <rostedt@goodmis.org>",
"date": "Tue, 6 Jan 2026 11:40:51 -0500",
"is_openbsd": false,
"thread_id": "b0e30f81-b06c-451b-abdc-ede71fa4a96b@linux.ibm.com.mbox.gz"
} |
lkml_critique | lkml |
[ with 6.18 being an LTS release, it might be a good time for this ]
The introduction of PREEMPT_LAZY was for multiple reasons:
- PREEMPT_RT suffered from over-scheduling, hurting performance compared to
!PREEMPT_RT.
- the introduction of (more) features that rely on preemption; like
folio_zero_user() w... | null | null | null | [PATCH] sched: Further restrict the preemption modes | Hi Peter.
On 12/19/25 3:45 PM, Peter Zijlstra wrote:
Maybe only change the default to LAZY, but keep other options possible
via dynamic update?
- When the kernel changes to lazy being the default, the scheduling
pattern can change and it may affect the workloads. having ability to
dynamically change to none/volun... | {
"author": "Shrikanth Hegde <sshegde@linux.ibm.com>",
"date": "Fri, 9 Jan 2026 16:53:04 +0530",
"is_openbsd": false,
"thread_id": "b0e30f81-b06c-451b-abdc-ede71fa4a96b@linux.ibm.com.mbox.gz"
} |
lkml_critique | lkml |
[ with 6.18 being an LTS release, it might be a good time for this ]
The introduction of PREEMPT_LAZY was for multiple reasons:
- PREEMPT_RT suffered from over-scheduling, hurting performance compared to
!PREEMPT_RT.
- the introduction of (more) features that rely on preemption; like
folio_zero_user() w... | null | null | null | [PATCH] sched: Further restrict the preemption modes | The following commit has been merged into the sched/core branch of tip:
Commit-ID: 7dadeaa6e851e7d67733f3e24fc53ee107781d0f
Gitweb: https://git.kernel.org/tip/7dadeaa6e851e7d67733f3e24fc53ee107781d0f
Author: Peter Zijlstra <peterz@infradead.org>
AuthorDate: Thu, 18 Dec 2025 15:25:10 +01:00
Committ... | {
"author": "\"tip-bot2 for Peter Zijlstra\" <tip-bot2@linutronix.de>",
"date": "Mon, 12 Jan 2026 08:03:23 -0000",
"is_openbsd": false,
"thread_id": "b0e30f81-b06c-451b-abdc-ede71fa4a96b@linux.ibm.com.mbox.gz"
} |
lkml_critique | lkml |
[ with 6.18 being an LTS release, it might be a good time for this ]
The introduction of PREEMPT_LAZY was for multiple reasons:
- PREEMPT_RT suffered from over-scheduling, hurting performance compared to
!PREEMPT_RT.
- the introduction of (more) features that rely on preemption; like
folio_zero_user() w... | null | null | null | [PATCH] sched: Further restrict the preemption modes | On 19/12/2025 10:15, Peter Zijlstra wrote:
Hi Peter,
We are observing a performance regression on s390 since enabling PREEMPT_LAZY.
Test Environment
Architecture: s390
Setup:
Single KVM host running two identical guests
Guests are connected virtually via Open vSwitch
Workload: uperf streaming read test with 50 paral... | {
"author": "Ciunas Bennett <ciunas@linux.ibm.com>",
"date": "Tue, 24 Feb 2026 15:45:39 +0000",
"is_openbsd": false,
"thread_id": "b0e30f81-b06c-451b-abdc-ede71fa4a96b@linux.ibm.com.mbox.gz"
} |
lkml_critique | lkml |
[ with 6.18 being an LTS release, it might be a good time for this ]
The introduction of PREEMPT_LAZY was for multiple reasons:
- PREEMPT_RT suffered from over-scheduling, hurting performance compared to
!PREEMPT_RT.
- the introduction of (more) features that rely on preemption; like
folio_zero_user() w... | null | null | null | [PATCH] sched: Further restrict the preemption modes | On 2026-02-24 15:45:39 [+0000], Ciunas Bennett wrote:
PREEMPT_FULL schedules immediately if there is a preemption request
either due to a wake up of a task, or because the time slice is used up
(while in kernel).
PREEMPT_LAZY delays the preemption request, caused by the scheduling
event, either until the task returns ... | {
"author": "Sebastian Andrzej Siewior <bigeasy@linutronix.de>",
"date": "Tue, 24 Feb 2026 18:11:11 +0100",
"is_openbsd": false,
"thread_id": "b0e30f81-b06c-451b-abdc-ede71fa4a96b@linux.ibm.com.mbox.gz"
} |
lkml_critique | lkml |
[ with 6.18 being an LTS release, it might be a good time for this ]
The introduction of PREEMPT_LAZY was for multiple reasons:
- PREEMPT_RT suffered from over-scheduling, hurting performance compared to
!PREEMPT_RT.
- the introduction of (more) features that rely on preemption; like
folio_zero_user() w... | null | null | null | [PATCH] sched: Further restrict the preemption modes | On 2/24/26 16:45, Ciunas Bennett wrote:
When I look at top sched_switch kstacks on s390 with this workload, 20%
of them are worker_thread() -> schedule(), both with CONFIG_PREEMPT and
CONFIG_PREEMPT_LAZY. The others are vhost and idle.
On x86 I see only vhost and idle, but not worker_thread().
According to runql... | {
"author": "Ilya Leoshkevich <iii@linux.ibm.com>",
"date": "Wed, 25 Feb 2026 03:30:04 +0100",
"is_openbsd": false,
"thread_id": "b0e30f81-b06c-451b-abdc-ede71fa4a96b@linux.ibm.com.mbox.gz"
} |
lkml_critique | lkml |
[ with 6.18 being an LTS release, it might be a good time for this ]
The introduction of PREEMPT_LAZY was for multiple reasons:
- PREEMPT_RT suffered from over-scheduling, hurting performance compared to
!PREEMPT_RT.
- the introduction of (more) features that rely on preemption; like
folio_zero_user() w... | null | null | null | [PATCH] sched: Further restrict the preemption modes | On 24/02/2026 17:11, Sebastian Andrzej Siewior wrote:
Sorry was not clear here, so when I enable this there is also an improvement in PREEMPT_FULL
from 55Gb/s -> 60Gb/s
So I see an improvement in both test cases.
PREEMPT_LAZY: throughput improved from 40 Gb/s → 60 Gb/s
PREEMPT_FULL: throughput improved from 55 Gb/s ... | {
"author": "Ciunas Bennett <ciunas@linux.ibm.com>",
"date": "Wed, 25 Feb 2026 09:56:29 +0000",
"is_openbsd": false,
"thread_id": "b0e30f81-b06c-451b-abdc-ede71fa4a96b@linux.ibm.com.mbox.gz"
} |
lkml_critique | lkml |
[ with 6.18 being an LTS release, it might be a good time for this ]
The introduction of PREEMPT_LAZY was for multiple reasons:
- PREEMPT_RT suffered from over-scheduling, hurting performance compared to
!PREEMPT_RT.
- the introduction of (more) features that rely on preemption; like
folio_zero_user() w... | null | null | null | [PATCH] sched: Further restrict the preemption modes | On Fri, Jan 09, 2026 at 04:53:04PM +0530, Shrikanth Hegde wrote:
I suppose we could do this. I just worry people will end up with 'echo
volatile > /debug/sched/preempt' in their startup script, rather than
trying to actually debug their issues.
Anybody with enough knowledge to be useful, can edit this line on their
... | {
"author": "Peter Zijlstra <peterz@infradead.org>",
"date": "Wed, 25 Feb 2026 11:53:45 +0100",
"is_openbsd": false,
"thread_id": "b0e30f81-b06c-451b-abdc-ede71fa4a96b@linux.ibm.com.mbox.gz"
} |
lkml_critique | lkml |
[ with 6.18 being an LTS release, it might be a good time for this ]
The introduction of PREEMPT_LAZY was for multiple reasons:
- PREEMPT_RT suffered from over-scheduling, hurting performance compared to
!PREEMPT_RT.
- the introduction of (more) features that rely on preemption; like
folio_zero_user() w... | null | null | null | [PATCH] sched: Further restrict the preemption modes | On 2/25/26 4:23 PM, Peter Zijlstra wrote:
Ack.
That's probably hungtask report right?
IIUC that would be independent of preemption model. | {
"author": "Shrikanth Hegde <sshegde@linux.ibm.com>",
"date": "Wed, 25 Feb 2026 18:26:07 +0530",
"is_openbsd": false,
"thread_id": "b0e30f81-b06c-451b-abdc-ede71fa4a96b@linux.ibm.com.mbox.gz"
} |
lkml_critique | lkml |
[ with 6.18 being an LTS release, it might be a good time for this ]
The introduction of PREEMPT_LAZY was for multiple reasons:
- PREEMPT_RT suffered from over-scheduling, hurting performance compared to
!PREEMPT_RT.
- the introduction of (more) features that rely on preemption; like
folio_zero_user() w... | null | null | null | [PATCH] sched: Further restrict the preemption modes | Am 24.02.26 um 21:30 schrieb Ilya Leoshkevich:
So in fact Doug is working on that at the moment. There are some corner
cases where we had concerns as we have to pin the guest pages holding
the interrupt bits. This was secure execution, I need to followup if
we have already solved those cases. But we can try if the cur... | {
"author": "Christian Borntraeger <borntraeger@linux.ibm.com>",
"date": "Wed, 25 Feb 2026 11:33:31 -0500",
"is_openbsd": false,
"thread_id": "b0e30f81-b06c-451b-abdc-ede71fa4a96b@linux.ibm.com.mbox.gz"
} |
lkml_critique | lkml |
[ with 6.18 being an LTS release, it might be a good time for this ]
The introduction of PREEMPT_LAZY was for multiple reasons:
- PREEMPT_RT suffered from over-scheduling, hurting performance compared to
!PREEMPT_RT.
- the introduction of (more) features that rely on preemption; like
folio_zero_user() w... | null | null | null | [PATCH] sched: Further restrict the preemption modes | On 2/25/26 11:33 AM, Christian Borntraeger wrote:
Christian, the patch is very close to ready. The last step, I rebased on
Master today to pickup the latest changes to interrupt.c. I am building
that now and will test for non-SE and SE environments. I have been
testing my solution for SE environments for a few week... | {
"author": "Douglas Freimuth <freimuth@linux.ibm.com>",
"date": "Wed, 25 Feb 2026 13:30:13 -0500",
"is_openbsd": false,
"thread_id": "b0e30f81-b06c-451b-abdc-ede71fa4a96b@linux.ibm.com.mbox.gz"
} |
lkml_critique | lkml |
[ with 6.18 being an LTS release, it might be a good time for this ]
The introduction of PREEMPT_LAZY was for multiple reasons:
- PREEMPT_RT suffered from over-scheduling, hurting performance compared to
!PREEMPT_RT.
- the introduction of (more) features that rely on preemption; like
folio_zero_user() w... | null | null | null | [PATCH] sched: Further restrict the preemption modes | On Wed, 25 Feb 2026 11:53:45 +0100
Peter Zijlstra <peterz@infradead.org> wrote:
That's unique per task right? As tracing is global it requires the
clock to be monotonic, and I'm guessing a single sched_switch will
break that.
Now if one wants to trace how long kernel paths are, I'm sure we could
trivially make a new... | {
"author": "Steven Rostedt <rostedt@goodmis.org>",
"date": "Wed, 25 Feb 2026 19:48:09 -0500",
"is_openbsd": false,
"thread_id": "b0e30f81-b06c-451b-abdc-ede71fa4a96b@linux.ibm.com.mbox.gz"
} |
lkml_critique | lkml |
[ with 6.18 being an LTS release, it might be a good time for this ]
The introduction of PREEMPT_LAZY was for multiple reasons:
- PREEMPT_RT suffered from over-scheduling, hurting performance compared to
!PREEMPT_RT.
- the introduction of (more) features that rely on preemption; like
folio_zero_user() w... | null | null | null | [PATCH] sched: Further restrict the preemption modes | On 2/26/26 6:18 AM, Steven Rostedt wrote:
That is good idea.
With preempt=full/lazy a long running kernel task can get
preempted if it is running in preemptible section. that's okay.
My intent was to have a tracer that can say, look this kernel task took this much time
before it completed. For some task such as lon... | {
"author": "Shrikanth Hegde <sshegde@linux.ibm.com>",
"date": "Thu, 26 Feb 2026 11:00:14 +0530",
"is_openbsd": false,
"thread_id": "b0e30f81-b06c-451b-abdc-ede71fa4a96b@linux.ibm.com.mbox.gz"
} |
lkml_critique | lkml |
[ with 6.18 being an LTS release, it might be a good time for this ]
The introduction of PREEMPT_LAZY was for multiple reasons:
- PREEMPT_RT suffered from over-scheduling, hurting performance compared to
!PREEMPT_RT.
- the introduction of (more) features that rely on preemption; like
folio_zero_user() w... | null | null | null | [PATCH] sched: Further restrict the preemption modes | On Thu, 26 Feb 2026 11:00:14 +0530
Shrikanth Hegde <sshegde@linux.ibm.com> wrote:
Yeah, I think something like this should be added now that LAZY will
prevent us from knowing where in the kernel is really going on for a long
time.
Tracers can be set to only watch a single task. The function and function
graph trace... | {
"author": "Steven Rostedt <rostedt@goodmis.org>",
"date": "Thu, 26 Feb 2026 12:22:52 -0500",
"is_openbsd": false,
"thread_id": "b0e30f81-b06c-451b-abdc-ede71fa4a96b@linux.ibm.com.mbox.gz"
} |
lkml_critique | lkml |
[ with 6.18 being an LTS release, it might be a good time for this ]
The introduction of PREEMPT_LAZY was for multiple reasons:
- PREEMPT_RT suffered from over-scheduling, hurting performance compared to
!PREEMPT_RT.
- the introduction of (more) features that rely on preemption; like
folio_zero_user() w... | null | null | null | [PATCH] sched: Further restrict the preemption modes | Hi Steven.
On 2/26/26 10:52 PM, Steven Rostedt wrote:
That would be the goal.
That was a hardlockup. wrong example.
All I was saying, there have been fixes which solved softlockup issues
without using cond_resched. But seeing softlockup was important to know
that issue existed.
Some reference commit I think that... | {
"author": "Shrikanth Hegde <sshegde@linux.ibm.com>",
"date": "Fri, 27 Feb 2026 14:39:42 +0530",
"is_openbsd": false,
"thread_id": "b0e30f81-b06c-451b-abdc-ede71fa4a96b@linux.ibm.com.mbox.gz"
} |
lkml_critique | lkml |
[ with 6.18 being an LTS release, it might be a good time for this ]
The introduction of PREEMPT_LAZY was for multiple reasons:
- PREEMPT_RT suffered from over-scheduling, hurting performance compared to
!PREEMPT_RT.
- the introduction of (more) features that rely on preemption; like
folio_zero_user() w... | null | null | null | [PATCH] sched: Further restrict the preemption modes | On Fri, 27 Feb 2026 14:39:42 +0530
Shrikanth Hegde <sshegde@linux.ibm.com> wrote:
Well, I think the detection can be done with timings between schedules.
What's the longest running task without any voluntary schedule. Then you
can add function graph tracing to it where it can possibly trigger in the
location that det... | {
"author": "Steven Rostedt <rostedt@goodmis.org>",
"date": "Fri, 27 Feb 2026 09:53:34 -0500",
"is_openbsd": false,
"thread_id": "b0e30f81-b06c-451b-abdc-ede71fa4a96b@linux.ibm.com.mbox.gz"
} |
lkml_critique | lkml |
[ with 6.18 being an LTS release, it might be a good time for this ]
The introduction of PREEMPT_LAZY was for multiple reasons:
- PREEMPT_RT suffered from over-scheduling, hurting performance compared to
!PREEMPT_RT.
- the introduction of (more) features that rely on preemption; like
folio_zero_user() w... | null | null | null | [PATCH] sched: Further restrict the preemption modes | Hi Steve.
On 2/27/26 8:23 PM, Steven Rostedt wrote:
Yep. Will try to do this.
Someone from our tracing team wanted to give this a try too. Lets see. | {
"author": "Shrikanth Hegde <sshegde@linux.ibm.com>",
"date": "Fri, 27 Feb 2026 20:58:33 +0530",
"is_openbsd": false,
"thread_id": "b0e30f81-b06c-451b-abdc-ede71fa4a96b@linux.ibm.com.mbox.gz"
} |
lkml_critique | lkml | Hi,
Some endpoint platforms cannot use a GIC ITS-backed MSI domain for
EP-side doorbells. In those cases, endpoint function (EPF) drivers
cannot provide a doorbell to the root complex (RC), and features such as
vNTB may fall back to polling with significantly higher latency.
This series adds an alternate doorbell bac... | null | null | null | [PATCH v9 0/7] PCI: endpoint: pci-ep-msi: Add embedded doorbell fallback | Endpoint controller drivers may integrate auxiliary blocks (e.g. DMA
engines) whose register windows and descriptor memories metadata need to
be exposed to a remote peer. Endpoint function drivers need a generic
way to discover such resources without hard-coding controller-specific
helpers.
Add pci_epc_get_aux_resourc... | {
"author": "Koichiro Den <den@valinux.co.jp>",
"date": "Thu, 19 Feb 2026 17:13:12 +0900",
"is_openbsd": false,
"thread_id": "aaG5asXVV5sxRbnQ@ryzen.mbox.gz"
} |
lkml_critique | lkml | Hi,
Some endpoint platforms cannot use a GIC ITS-backed MSI domain for
EP-side doorbells. In those cases, endpoint function (EPF) drivers
cannot provide a doorbell to the root complex (RC), and features such as
vNTB may fall back to polling with significantly higher latency.
This series adds an alternate doorbell bac... | null | null | null | [PATCH v9 0/7] PCI: endpoint: pci-ep-msi: Add embedded doorbell fallback | Implement the EPC aux-resource API for DesignWare endpoint controllers
with integrated eDMA.
Report:
- DMA controller MMIO window (PCI_EPC_AUX_DMA_CTRL_MMIO)
- interrupt-emulation doorbell register (PCI_EPC_AUX_DOORBELL_MMIO),
including its Linux IRQ and the data value to write to trigger the
interrupt
-... | {
"author": "Koichiro Den <den@valinux.co.jp>",
"date": "Thu, 19 Feb 2026 17:13:14 +0900",
"is_openbsd": false,
"thread_id": "aaG5asXVV5sxRbnQ@ryzen.mbox.gz"
} |
lkml_critique | lkml | Hi,
Some endpoint platforms cannot use a GIC ITS-backed MSI domain for
EP-side doorbells. In those cases, endpoint function (EPF) drivers
cannot provide a doorbell to the root complex (RC), and features such as
vNTB may fall back to polling with significantly higher latency.
This series adds an alternate doorbell bac... | null | null | null | [PATCH v9 0/7] PCI: endpoint: pci-ep-msi: Add embedded doorbell fallback | Some DesignWare PCIe controllers integrate an eDMA block whose registers
are located in a dedicated register window. Endpoint function drivers
may need the physical base and size of this window to map/expose it to a
peer.
Record the physical base and size of the integrated eDMA register window
in struct dw_pcie.
Revi... | {
"author": "Koichiro Den <den@valinux.co.jp>",
"date": "Thu, 19 Feb 2026 17:13:13 +0900",
"is_openbsd": false,
"thread_id": "aaG5asXVV5sxRbnQ@ryzen.mbox.gz"
} |
lkml_critique | lkml | Hi,
Some endpoint platforms cannot use a GIC ITS-backed MSI domain for
EP-side doorbells. In those cases, endpoint function (EPF) drivers
cannot provide a doorbell to the root complex (RC), and features such as
vNTB may fall back to polling with significantly higher latency.
This series adds an alternate doorbell bac... | null | null | null | [PATCH v9 0/7] PCI: endpoint: pci-ep-msi: Add embedded doorbell fallback | Prepare pci-ep-msi for non-MSI doorbell backends.
Factor MSI doorbell allocation into a helper and extend struct
pci_epf_doorbell_msg with:
- irq_flags: required IRQ request flags (e.g. IRQF_SHARED for some
backends)
- type: doorbell backend type
- bar/offset: pre-exposed doorbell target location, if any
I... | {
"author": "Koichiro Den <den@valinux.co.jp>",
"date": "Thu, 19 Feb 2026 17:13:15 +0900",
"is_openbsd": false,
"thread_id": "aaG5asXVV5sxRbnQ@ryzen.mbox.gz"
} |
lkml_critique | lkml | Hi,
Some endpoint platforms cannot use a GIC ITS-backed MSI domain for
EP-side doorbells. In those cases, endpoint function (EPF) drivers
cannot provide a doorbell to the root complex (RC), and features such as
vNTB may fall back to polling with significantly higher latency.
This series adds an alternate doorbell bac... | null | null | null | [PATCH v9 0/7] PCI: endpoint: pci-ep-msi: Add embedded doorbell fallback | Some endpoint platforms cannot use platform MSI / GIC ITS to implement
EP-side doorbells. In those cases, EPF drivers cannot provide an
interrupt-driven doorbell and often fall back to polling.
Add an "embedded" doorbell backend that uses a controller-integrated
doorbell target (e.g. DesignWare integrated eDMA interru... | {
"author": "Koichiro Den <den@valinux.co.jp>",
"date": "Thu, 19 Feb 2026 17:13:18 +0900",
"is_openbsd": false,
"thread_id": "aaG5asXVV5sxRbnQ@ryzen.mbox.gz"
} |
lkml_critique | lkml | Hi,
Some endpoint platforms cannot use a GIC ITS-backed MSI domain for
EP-side doorbells. In those cases, endpoint function (EPF) drivers
cannot provide a doorbell to the root complex (RC), and features such as
vNTB may fall back to polling with significantly higher latency.
This series adds an alternate doorbell bac... | null | null | null | [PATCH v9 0/7] PCI: endpoint: pci-ep-msi: Add embedded doorbell fallback | Support doorbell backends where the doorbell target is already exposed
via a platform-owned fixed BAR mapping and/or where the doorbell IRQ
must be requested with specific flags.
When pci_epf_alloc_doorbell() provides db_msg[].bar/offset, reuse the
pre-exposed BAR window and skip programming a new inbound mapping. Als... | {
"author": "Koichiro Den <den@valinux.co.jp>",
"date": "Thu, 19 Feb 2026 17:13:16 +0900",
"is_openbsd": false,
"thread_id": "aaG5asXVV5sxRbnQ@ryzen.mbox.gz"
} |
lkml_critique | lkml | Hi,
Some endpoint platforms cannot use a GIC ITS-backed MSI domain for
EP-side doorbells. In those cases, endpoint function (EPF) drivers
cannot provide a doorbell to the root complex (RC), and features such as
vNTB may fall back to polling with significantly higher latency.
This series adds an alternate doorbell bac... | null | null | null | [PATCH v9 0/7] PCI: endpoint: pci-ep-msi: Add embedded doorbell fallback | pci-epf-test advertises the doorbell target to the RC as a BAR number
and an offset, and the RC rings the doorbell with a single DWORD MMIO
write.
Some doorbell backends may report that the doorbell target is already
exposed via a platform-owned fixed BAR (db_msg[0].bar/offset). In that
case, reuse the pre-exposed win... | {
"author": "Koichiro Den <den@valinux.co.jp>",
"date": "Thu, 19 Feb 2026 17:13:17 +0900",
"is_openbsd": false,
"thread_id": "aaG5asXVV5sxRbnQ@ryzen.mbox.gz"
} |
lkml_critique | lkml | Hi,
Some endpoint platforms cannot use a GIC ITS-backed MSI domain for
EP-side doorbells. In those cases, endpoint function (EPF) drivers
cannot provide a doorbell to the root complex (RC), and features such as
vNTB may fall back to polling with significantly higher latency.
This series adds an alternate doorbell bac... | null | null | null | [PATCH v9 0/7] PCI: endpoint: pci-ep-msi: Add embedded doorbell fallback | On 2/19/2026 1:43 PM, Koichiro Den wrote:
The return value of pci_epc_get_features() seems to be used here
without checking for NULL.
Since this function can return NULL, and other EPF drivers
(pci-epf-test.c, pci-epf-ntb.c) handle that case,
is VNTB assuming that epc_features is always non-NULL,
or should a defensiv... | {
"author": "ALOK TIWARI <alok.a.tiwari@oracle.com>",
"date": "Thu, 19 Feb 2026 22:00:19 +0530",
"is_openbsd": false,
"thread_id": "aaG5asXVV5sxRbnQ@ryzen.mbox.gz"
} |
lkml_critique | lkml | Hi,
Some endpoint platforms cannot use a GIC ITS-backed MSI domain for
EP-side doorbells. In those cases, endpoint function (EPF) drivers
cannot provide a doorbell to the root complex (RC), and features such as
vNTB may fall back to polling with significantly higher latency.
This series adds an alternate doorbell bac... | null | null | null | [PATCH v9 0/7] PCI: endpoint: pci-ep-msi: Add embedded doorbell fallback | On Thu, Feb 19, 2026 at 10:00:19PM +0530, ALOK TIWARI wrote:
Thanks for the comment, good catch.
AFAICT, this is a pre-existing issue (at least since the initial vNTB merge,
commit e35f56bb0330), and the same pattern can be found in a few other paths in
epf-vntb, such as:
- epf_ntb_config_spad_bar_alloc()
- epf_... | {
"author": "Koichiro Den <den@valinux.co.jp>",
"date": "Fri, 20 Feb 2026 12:35:31 +0900",
"is_openbsd": false,
"thread_id": "aaG5asXVV5sxRbnQ@ryzen.mbox.gz"
} |
lkml_critique | lkml | Hi,
Some endpoint platforms cannot use a GIC ITS-backed MSI domain for
EP-side doorbells. In those cases, endpoint function (EPF) drivers
cannot provide a doorbell to the root complex (RC), and features such as
vNTB may fall back to polling with significantly higher latency.
This series adds an alternate doorbell bac... | null | null | null | [PATCH v9 0/7] PCI: endpoint: pci-ep-msi: Add embedded doorbell fallback | On Fri, Feb 20, 2026 at 12:35:31PM +0900, Koichiro Den wrote:
We should really clean this up somehow.
The problems are:
1) A long time ago, not all EPC driver had a get_features callback.
Now, EPC drivers do have such a callback.
Ideally, we should probably add a check that an EPC driver implements
epc->op... | {
"author": "Niklas Cassel <cassel@kernel.org>",
"date": "Fri, 20 Feb 2026 11:27:05 +0100",
"is_openbsd": false,
"thread_id": "aaG5asXVV5sxRbnQ@ryzen.mbox.gz"
} |
lkml_critique | lkml | Hi,
Some endpoint platforms cannot use a GIC ITS-backed MSI domain for
EP-side doorbells. In those cases, endpoint function (EPF) drivers
cannot provide a doorbell to the root complex (RC), and features such as
vNTB may fall back to polling with significantly higher latency.
This series adds an alternate doorbell bac... | null | null | null | [PATCH v9 0/7] PCI: endpoint: pci-ep-msi: Add embedded doorbell fallback | On 2/20/2026 9:05 AM, Koichiro Den wrote:
Yes, agreed this is independent of the doorbell rework.
I will send a separate patch for this.
Thanks,
Alok | {
"author": "ALOK TIWARI <alok.a.tiwari@oracle.com>",
"date": "Fri, 20 Feb 2026 20:44:43 +0530",
"is_openbsd": false,
"thread_id": "aaG5asXVV5sxRbnQ@ryzen.mbox.gz"
} |
lkml_critique | lkml | Hi,
Some endpoint platforms cannot use a GIC ITS-backed MSI domain for
EP-side doorbells. In those cases, endpoint function (EPF) drivers
cannot provide a doorbell to the root complex (RC), and features such as
vNTB may fall back to polling with significantly higher latency.
This series adds an alternate doorbell bac... | null | null | null | [PATCH v9 0/7] PCI: endpoint: pci-ep-msi: Add embedded doorbell fallback | On Thu, Feb 19, 2026 at 05:13:18PM +0900, Koichiro Den wrote:
On second thought, I'm wondering whether it makes sense to handle the case where
the embedded doorbell target resides behind an IOMMU in this series.
In v9, we simply expose the raw physical address without establishing an IOMMU
mapping. When the EPC paren... | {
"author": "Koichiro Den <den@valinux.co.jp>",
"date": "Sat, 21 Feb 2026 02:42:35 +0900",
"is_openbsd": false,
"thread_id": "aaG5asXVV5sxRbnQ@ryzen.mbox.gz"
} |
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