From: Bagas Sanjaya <bagasdotme@gmail.com>
To: wenyang.linux@foxmail.com,
Alexander Viro <viro@zeniv.linux.org.uk>,
Jens Axboe <axboe@kernel.dk>,
Christian Brauner <brauner@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>, Dylan Yudaken <dylany@fb.com>,
David Woodhouse <dwmw@amazon.co.uk>,
Paolo Bonzini <pbonzini@redhat.com>, Fu Wei <wefu@redhat.com>,
linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] eventfd: support delayed wakeup for non-semaphore eventfd to reduce cpu utilization
Date: Mon, 17 Apr 2023 15:22:55 +0700 [thread overview]
Message-ID: <ZD0B3wGasaWT0rsr@debian.me> (raw)
In-Reply-To: <tencent_AF886EF226FD9F39D28FE4D9A94A95FA2605@qq.com>
[-- Attachment #1: Type: text/plain, Size: 887 bytes --]
On Sun, Apr 16, 2023 at 07:31:55PM +0800, wenyang.linux@foxmail.com wrote:
> +eventfd_wakeup_delay_msec
> +------------------
Please match the section underline length as the section text above.
> +Frequent writing of an eventfd can also lead to frequent wakeup of the peer
> +read process, resulting in significant cpu overhead.
> +How ever for the NON SEMAPHORE eventfd, if it's counter has a nonzero value,
> +then a read(2) returns 8 bytes containing that value, and the counter's value
reading eventfd?
> +is reset to zero.
> +So it coule be optimized as follows: N event_writes vs ONE event_read.
> +By adding a configurable delay after eventfd_write, these unnecessary wakeup
> +operations are avoided.
What is the connection from optimization you described to eventfd_write
delay?
Thanks.
--
An old man doll... just what I always wanted! - Clara
[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 228 bytes --]
next prev parent reply other threads:[~2023-04-17 8:23 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-04-16 11:31 [PATCH] eventfd: support delayed wakeup for non-semaphore eventfd to reduce cpu utilization wenyang.linux
2023-04-17 8:22 ` Bagas Sanjaya [this message]
2023-04-17 12:44 ` kernel test robot
2023-04-17 14:38 ` Jens Axboe
2023-04-17 16:32 ` Wen Yang
2023-04-19 2:15 ` Jens Axboe
2023-04-19 9:12 ` Christian Brauner
2023-04-19 15:23 ` Wen Yang
2023-04-19 16:42 ` Jens Axboe
2023-04-20 17:44 ` Wen Yang
2023-05-04 16:01 ` Wen Yang
[not found] <20230417000711.1100-1-hdanton@sina.com>
2023-04-18 14:12 ` Wen Yang
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=ZD0B3wGasaWT0rsr@debian.me \
--to=bagasdotme@gmail.com \
--cc=axboe@kernel.dk \
--cc=brauner@kernel.org \
--cc=dwmw@amazon.co.uk \
--cc=dylany@fb.com \
--cc=hch@lst.de \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=pbonzini@redhat.com \
--cc=viro@zeniv.linux.org.uk \
--cc=wefu@redhat.com \
--cc=wenyang.linux@foxmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.