From: Christian Schmid <webmaster@rapidforum.com>
To: Lennert Buytenhek <buytenh@wantstofly.org>
Cc: bert hubert <ahu@ds9a.nl>, Nivedita Singhvi <niv@us.ibm.com>,
netdev@oss.sgi.com
Subject: Re: many outgoing tcp sockets are slower than a few
Date: Mon, 21 Feb 2005 18:17:16 +0100 [thread overview]
Message-ID: <421A179C.1030505@rapidforum.com> (raw)
In-Reply-To: <20050221120223.GA30348@xi.wantstofly.org>
Lennert Buytenhek wrote:
> On Mon, Feb 21, 2005 at 11:36:14AM +0100, Christian Schmid wrote:
>
>
>>Outgoing data. I am using sendfile() to send the file on a non-blocking
>>socket but the call blocks for 100 ms per socket if I get over 3000
>>sockets. Thats causing the massive slowdown in sum. I first thought its a
>>disk-issue but I tried with pure-cache data as well and it still blocks.
>
>
> O_NONBLOCK send() is really nonblocking, but O_NONBLOCK sendfile()
> really isn't, as it still does the disk read (if any) synchronously.
>
> How are you making sure that you're sending "pure-cache data"?
Because thats the first I excluded. I changed the program by replacing sendfile with a
caching-routine plus syswrite. And it was really interesting that the syswrite was the one which
needs most of the real-time, not the caching-routine. syswrite blocked 100 ms per socket.
>
>
> --L
>
>
next prev parent reply other threads:[~2005-02-21 17:17 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-02-21 0:05 Annoying bug with many sockets Christian Schmid
2005-02-21 0:26 ` Nivedita Singhvi
2005-02-21 0:35 ` Christian Schmid
2005-02-21 9:01 ` many outgoing tcp sockets are slower than a few bert hubert
2005-02-21 10:36 ` Christian Schmid
2005-02-21 12:02 ` Lennert Buytenhek
2005-02-21 12:25 ` bert hubert
2005-02-21 12:36 ` Lennert Buytenhek
2005-02-21 17:17 ` Christian Schmid [this message]
2005-02-21 17:24 ` bert hubert
2005-02-21 19:10 ` Christian Schmid
2005-02-21 17:29 ` Lennert Buytenhek
2005-02-21 19:11 ` Christian Schmid
2005-02-21 13:59 ` Baruch Even
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=421A179C.1030505@rapidforum.com \
--to=webmaster@rapidforum.com \
--cc=ahu@ds9a.nl \
--cc=buytenh@wantstofly.org \
--cc=netdev@oss.sgi.com \
--cc=niv@us.ibm.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).