From: Jakub Kicinski <kuba@kernel.org>
To: Stefan Roesch <shr@devkernel.io>
Cc: io-uring@vger.kernel.org, kernel-team@fb.com, axboe@kernel.dk,
ammarfaizi2@gnuweeb.org, netdev@vger.kernel.org,
olivier@trillion01.com
Subject: Re: [PATCH v13 1/7] net: split off __napi_busy_poll from napi_busy_poll
Date: Thu, 1 Jun 2023 21:26:04 -0700 [thread overview]
Message-ID: <20230601212604.3f5e2342@kernel.org> (raw)
In-Reply-To: <qvqwedmuv6mu.fsf@devbig1114.prn1.facebook.com>
On Thu, 01 Jun 2023 21:12:10 -0700 Stefan Roesch wrote:
> The problem with checking need_resched in loop_end is that need_resched
> can be false in loop_end, however the check for need_resched in
> napi_busy_loop succeeds. This means that we unlock the rcu read lock and
> call schedule. However the code in io_napi_blocking_busy_loop still
> believes we hold the read lock.
Ah, yes, now it makes sense.
Yeah, that's a race, scratch the workaround idea then.
Let's work on revising the patches, we'll see where we
are in the development process when they're ready.
next prev parent reply other threads:[~2023-06-02 4:26 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-18 21:17 [PATCH v13 0/7] io_uring: add napi busy polling support Stefan Roesch
2023-05-18 21:17 ` [PATCH v13 1/7] net: split off __napi_busy_poll from napi_busy_poll Stefan Roesch
[not found] ` <20230531103224.17a462cc@kernel.org>
2023-05-31 19:16 ` Stefan Roesch
2023-06-01 4:15 ` Jakub Kicinski
2023-06-02 4:12 ` Stefan Roesch
2023-06-02 4:26 ` Jakub Kicinski [this message]
[not found] ` <20230531102644.7f171d48@kernel.org>
2023-06-05 17:47 ` Stefan Roesch
2023-06-05 18:00 ` Jakub Kicinski
2023-05-18 21:17 ` [PATCH v13 2/7] net: introduce napi_busy_loop_rcu() Stefan Roesch
[not found] ` <20230531102915.0afc570b@kernel.org>
2023-06-05 17:45 ` Stefan Roesch
2023-05-18 21:17 ` [PATCH v13 3/7] io-uring: move io_wait_queue definition to header file Stefan Roesch
2023-05-18 21:17 ` [PATCH v13 4/7] io-uring: add napi busy poll support Stefan Roesch
2023-05-19 1:26 ` Jens Axboe
2023-05-19 23:11 ` Stefan Roesch
2023-05-19 9:53 ` Simon Horman
2023-05-19 23:17 ` Stefan Roesch
2023-05-18 21:17 ` [PATCH v13 5/7] io-uring: add sqpoll support for napi busy poll Stefan Roesch
2023-05-19 0:11 ` kernel test robot
2023-05-19 1:13 ` Jens Axboe
2023-05-19 23:29 ` Stefan Roesch
2023-05-19 4:35 ` kernel test robot
2023-05-18 21:17 ` [PATCH v13 6/7] io_uring: add register/unregister napi function Stefan Roesch
2023-05-19 1:30 ` Jens Axboe
2023-05-18 21:17 ` [PATCH v13 7/7] io_uring: add prefer busy poll to register and unregister napi api Stefan Roesch
2023-05-19 1:31 ` [PATCH v13 0/7] io_uring: add napi busy polling support Jens Axboe
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