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: 11+ 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
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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).