linux/io_uring
Jens Axboe e87fa62ebc io_uring/fdinfo: remove need for sqpoll lock for thread/pid retrieval
[ Upstream commit a0d45c3f59 ]

A previous commit added a trylock for getting the SQPOLL thread info via
fdinfo, but this introduced a regression where we often fail to get it if
the thread is busy. For that case, we end up not printing the current CPU
and PID info.

Rather than rely on this lock, just print the pid we already stored in
the io_sq_data struct, and ensure we update the current CPU every time
we've slept or potentially rescheduled. The latter won't potentially be
100% accurate, but that wasn't the case before either as the task can
get migrated at any time unless it has been pinned at creation time.

We retain keeping the io_sq_data dereference inside the ctx->uring_lock,
as it has always been, as destruction of the thread and data happen below
that. We could make this RCU safe, but there's little point in doing that.

With this, we always print the last valid information we had, rather than
have spurious outputs with missing information.

Fixes: 7644b1a1c9 ("io_uring/fdinfo: lock SQ thread while retrieving thread cpu/pid")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-11-28 17:14:56 +00:00
..
advise.c io_uring: always go async for unsupported fadvise flags 2023-01-29 15:18:26 -07:00
advise.h
alloc_cache.h io_uring/rsrc: consolidate node caching 2023-04-12 12:09:41 -06:00
cancel.c io_uring: use io_file_from_index in __io_sync_cancel 2023-06-20 09:36:22 -06:00
cancel.h
epoll.c io_uring: undeprecate epoll_ctl support 2023-05-26 20:22:41 -06:00
epoll.h
fdinfo.c io_uring/fdinfo: remove need for sqpoll lock for thread/pid retrieval 2023-11-28 17:14:56 +00:00
fdinfo.h
filetable.c io_uring: add helpers to decode the fixed file file_ptr 2023-06-20 09:36:22 -06:00
filetable.h io_uring: add helpers to decode the fixed file file_ptr 2023-06-20 09:36:22 -06:00
fs.c io_uring/fs: remove sqe->rw_flags checking from LINKAT 2023-10-06 13:16:23 +02:00
fs.h
io_uring.c io_uring: fix crash with IORING_SETUP_NO_MMAP and invalid SQ ring address 2023-10-25 12:16:12 +02:00
io_uring.h io_uring: ensure io_lockdep_assert_cq_locked() handles disabled rings 2023-10-10 22:02:57 +02:00
io-wq.c io-wq: fully initialize wqe before calling cpuhp_state_add_instance_nocalls() 2023-10-25 12:16:20 +02:00
io-wq.h io_uring: break out of iowq iopoll on teardown 2023-09-13 09:53:51 +02:00
kbuf.c io_uring/kbuf: Allow the full buffer id space for provided buffers 2023-11-20 11:57:01 +01:00
kbuf.h io_uring: add support for user mapped provided buffer ring 2023-04-03 07:14:21 -06:00
Makefile
msg_ring.c io_uring: use io_file_from_index in io_msg_grab_file 2023-06-20 09:36:22 -06:00
msg_ring.h io_uring: get rid of double locking 2022-12-07 06:47:13 -07:00
net.c io_uring/net: ensure socket is marked connected on connect retry 2023-11-20 11:57:25 +01:00
net.h io_uring: Add KASAN support for alloc_caches 2023-04-03 07:16:14 -06:00
nop.c
nop.h
notif.c io_uring/notif: add constant for ubuf_info flags 2023-04-15 14:21:04 -06:00
notif.h io_uring/notif: add constant for ubuf_info flags 2023-04-15 14:21:04 -06:00
opdef.c io_uring: Pass whole sqe to commands 2023-05-04 08:19:05 -06:00
opdef.h io_uring: Split io_issue_def struct 2023-01-29 15:17:41 -07:00
openclose.c io_uring: correct check for O_TMPFILE 2023-08-07 12:34:23 -06:00
openclose.h
poll.c for-6.5/io_uring-2023-06-23 2023-06-26 12:30:26 -07:00
poll.h io_uring: avoid indirect function calls for the hottest task_work 2023-06-02 08:55:37 -06:00
refs.h
rsrc.c - Yosry Ahmed brought back some cgroup v1 stats in OOM logs. 2023-06-28 10:28:11 -07:00
rsrc.h io_uring/rsrc: disassociate nodes and rsrc_data 2023-04-18 19:38:26 -06:00
rw.c io_uring: kiocb_done() should *not* trust ->ki_pos if ->{read,write}_iter() failed 2023-11-08 14:09:03 +01:00
rw.h io_uring: avoid indirect function calls for the hottest task_work 2023-06-02 08:55:37 -06:00
slist.h io_uring: silence variable ‘prev’ set but not used warning 2023-03-09 10:10:58 -07:00
splice.c io_uring: for requests that require async, force it 2023-01-29 15:18:26 -07:00
splice.h
sqpoll.c io_uring/fdinfo: remove need for sqpoll lock for thread/pid retrieval 2023-11-28 17:14:56 +00:00
sqpoll.h io_uring/sqpoll: fix io-wq affinity when IORING_SETUP_SQPOLL is used 2023-09-13 09:53:51 +02:00
statx.c io_uring: for requests that require async, force it 2023-01-29 15:18:26 -07:00
statx.h
sync.c io_uring: for requests that require async, force it 2023-01-29 15:18:26 -07:00
sync.h
tctx.c io_uring: Add io_uring_setup flag to pre-register ring fd and never install it 2023-05-16 08:06:00 -06:00
tctx.h io_uring: simplify __io_uring_add_tctx_node 2022-10-07 12:25:30 -06:00
timeout.c io_uring: cleanup io_aux_cqe() API 2023-06-07 14:59:22 -06:00
timeout.h io_uring: remove unused return from io_disarm_next 2022-09-21 13:15:01 -06:00
uring_cmd.c io_uring/cmd: add cmd lazy tw wake helper 2023-05-25 08:54:06 -06:00
uring_cmd.h io_uring: Remove unnecessary BUILD_BUG_ON 2023-05-04 08:19:05 -06:00
xattr.c io_uring: for requests that require async, force it 2023-01-29 15:18:26 -07:00
xattr.h