From: Stefan Hajnoczi <stefanha@redhat.com>
To: axboe@kernel.dk
Cc: linux-kernel@vger.kernel.org, netdev@vger.kernel.org
Subject: Re: [PATCHSET v3 0/5] Add support for epoll min_wait
Date: Mon, 7 Nov 2022 15:56:01 -0500 [thread overview]
Message-ID: <Y2lw4Qc1uI+Ep+2C@fedora> (raw)
In-Reply-To: <20221030220203.31210-1-axboe@kernel.dk>
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Hi Jens,
NICs and storage controllers have interrupt mitigation/coalescing
mechanisms that are similar.
NVMe has an Aggregation Time (timeout) and an Aggregation Threshold
(counter) value. When a completion occurs, the device waits until the
timeout or until the completion counter value is reached.
If I've read the code correctly, min_wait is computed at the beginning
of epoll_wait(2). NVMe's Aggregation Time is computed from the first
completion.
It makes me wonder which approach is more useful for applications. With
the Aggregation Time approach applications can control how much extra
latency is added. What do you think about that approach?
Stefan
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next prev parent reply other threads:[~2022-11-07 20:57 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-30 22:01 [PATCHSET v3 0/5] Add support for epoll min_wait Jens Axboe
2022-10-30 22:01 ` [PATCH 1/6] eventpoll: cleanup branches around sleeping for events Jens Axboe
2022-10-30 22:01 ` [PATCH 2/6] eventpoll: don't pass in 'timed_out' to ep_busy_loop() Jens Axboe
2022-10-30 22:02 ` [PATCH 3/6] eventpoll: split out wait handling Jens Axboe
2022-10-30 22:02 ` [PATCH 4/6] eventpoll: move expires to epoll_wq Jens Axboe
2022-10-30 22:02 ` [PATCH 5/6] eventpoll: move file checking earlier for epoll_ctl() Jens Axboe
2022-10-30 22:02 ` [PATCH 6/6] eventpoll: add support for min-wait Jens Axboe
2022-11-08 22:14 ` Soheil Hassas Yeganeh
2022-11-08 22:20 ` Jens Axboe
2022-11-08 22:25 ` Willem de Bruijn
2022-11-08 22:29 ` Jens Axboe
2022-11-08 22:44 ` Willem de Bruijn
2022-11-08 22:41 ` Soheil Hassas Yeganeh
2022-12-01 18:00 ` Jens Axboe
2022-12-01 18:39 ` Soheil Hassas Yeganeh
2022-12-01 18:41 ` Jens Axboe
2022-11-02 17:46 ` [PATCHSET v3 0/5] Add support for epoll min_wait Willem de Bruijn
2022-11-02 17:54 ` Jens Axboe
2022-11-02 23:09 ` Willem de Bruijn
2022-11-02 23:37 ` Jens Axboe
2022-11-02 23:51 ` Willem de Bruijn
2022-11-02 23:57 ` Jens Axboe
2022-11-05 17:39 ` Jens Axboe
2022-11-05 18:05 ` Willem de Bruijn
2022-11-05 18:46 ` Jens Axboe
2022-11-07 13:25 ` Willem de Bruijn
2022-11-07 14:19 ` Jens Axboe
2022-11-07 10:10 ` David Laight
2022-11-07 20:56 ` Stefan Hajnoczi [this message]
2022-11-07 21:38 ` Jens Axboe
2022-11-08 14:00 ` Stefan Hajnoczi
2022-11-08 14:09 ` Jens Axboe
2022-11-08 16:10 ` Stefan Hajnoczi
2022-11-08 16:15 ` Jens Axboe
2022-11-08 17:24 ` Stefan Hajnoczi
2022-11-08 17:28 ` Jens Axboe
2022-11-08 20:29 ` Stefan Hajnoczi
2022-11-09 10:09 ` David Laight
2022-11-10 10:13 ` Willem de Bruijn
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