* [PATCH for-next] io_uring: remove ctx referencing from complete_post
@ 2021-09-15 11:04 Pavel Begunkov
2021-09-15 13:00 ` Hao Xu
2021-09-16 1:53 ` Jens Axboe
0 siblings, 2 replies; 4+ messages in thread
From: Pavel Begunkov @ 2021-09-15 11:04 UTC (permalink / raw)
To: Jens Axboe, io-uring
Now completions are done from task context, that means that it's either
the task itself, task_work or io-wq worker. In all those cases the ctx
will be staying alive by mutexing, explicit referencing or req
references by iowq. Remove extra ctx pinning from
io_req_complete_post().
Signed-off-by: Pavel Begunkov <[email protected]>
---
fs/io_uring.c | 10 ++--------
1 file changed, 2 insertions(+), 8 deletions(-)
diff --git a/fs/io_uring.c b/fs/io_uring.c
index 511fb8052ae9..c23f3218d52b 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -1816,17 +1816,11 @@ static void io_req_complete_post(struct io_kiocb *req, long res,
io_put_task(req->task, 1);
list_add(&req->inflight_entry, &ctx->locked_free_list);
ctx->locked_free_nr++;
- } else {
- if (!percpu_ref_tryget(&ctx->refs))
- req = NULL;
+ percpu_ref_put(&ctx->refs);
}
io_commit_cqring(ctx);
spin_unlock(&ctx->completion_lock);
-
- if (req) {
- io_cqring_ev_posted(ctx);
- percpu_ref_put(&ctx->refs);
- }
+ io_cqring_ev_posted(ctx);
}
static inline bool io_req_needs_clean(struct io_kiocb *req)
--
2.33.0
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH for-next] io_uring: remove ctx referencing from complete_post
2021-09-15 11:04 [PATCH for-next] io_uring: remove ctx referencing from complete_post Pavel Begunkov
@ 2021-09-15 13:00 ` Hao Xu
2021-09-15 13:07 ` Pavel Begunkov
2021-09-16 1:53 ` Jens Axboe
1 sibling, 1 reply; 4+ messages in thread
From: Hao Xu @ 2021-09-15 13:00 UTC (permalink / raw)
To: Pavel Begunkov, Jens Axboe, io-uring
在 2021/9/15 下午7:04, Pavel Begunkov 写道:
> Now completions are done from task context, that means that it's either
> the task itself, task_work or io-wq worker. In all those cases the ctx
system-wq as well, not sure if that matters.
> will be staying alive by mutexing, explicit referencing or req
> references by iowq. Remove extra ctx pinning from
> io_req_complete_post().
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH for-next] io_uring: remove ctx referencing from complete_post
2021-09-15 13:00 ` Hao Xu
@ 2021-09-15 13:07 ` Pavel Begunkov
0 siblings, 0 replies; 4+ messages in thread
From: Pavel Begunkov @ 2021-09-15 13:07 UTC (permalink / raw)
To: Hao Xu, Jens Axboe, io-uring
On 9/15/21 2:00 PM, Hao Xu wrote:
> 在 2021/9/15 下午7:04, Pavel Begunkov 写道:
>> Now completions are done from task context, that means that it's either
>> the task itself, task_work or io-wq worker. In all those cases the ctx
> system-wq as well, not sure if that matters.
Yep, missed in the description.
fwiw, io_fallback_req_func() explicitly pins ctx.
>> will be staying alive by mutexing, explicit referencing or req
>> references by iowq. Remove extra ctx pinning from
>> io_req_complete_post().
--
Pavel Begunkov
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH for-next] io_uring: remove ctx referencing from complete_post
2021-09-15 11:04 [PATCH for-next] io_uring: remove ctx referencing from complete_post Pavel Begunkov
2021-09-15 13:00 ` Hao Xu
@ 2021-09-16 1:53 ` Jens Axboe
1 sibling, 0 replies; 4+ messages in thread
From: Jens Axboe @ 2021-09-16 1:53 UTC (permalink / raw)
To: Pavel Begunkov, io-uring
On 9/15/21 5:04 AM, Pavel Begunkov wrote:
> Now completions are done from task context, that means that it's either
> the task itself, task_work or io-wq worker. In all those cases the ctx
> will be staying alive by mutexing, explicit referencing or req
> references by iowq. Remove extra ctx pinning from
> io_req_complete_post().
Applied, thanks.
--
Jens Axboe
^ permalink raw reply [flat|nested] 4+ messages in thread
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2021-09-15 11:04 [PATCH for-next] io_uring: remove ctx referencing from complete_post Pavel Begunkov
2021-09-15 13:00 ` Hao Xu
2021-09-15 13:07 ` Pavel Begunkov
2021-09-16 1:53 ` Jens Axboe
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