From: Bakul Shah <bakul@bitblocks.com>
To: Fans of the OS Plan 9 from Bell Labs <9fans@9fans.net>
Subject: Re: [9fans] fossil+venti performance question
Date: Fri, 8 May 2015 14:19:22 -0700 [thread overview]
Message-ID: <20150508211922.1118FB82A@mail.bitblocks.com> (raw)
In-Reply-To: Your message of "Fri, 08 May 2015 21:24:13 +0200." <20150508212413.7466429d@zinc.9fans.fr>
On Fri, 08 May 2015 21:24:13 +0200 David du Colombier <0intro@gmail.com> wrote:
> On the loopback medium, I suppose this is the opposite issue.
> Since the TCP stack didn't fix the MSS in the incoming
> connection, the programs sent multiple small 1500 bytes
> IP packets instead of large 16384 IP packets, but I don't
> know why it leads to such a slowdown.
Looking at the first few bytes in each dir of the initial TCP
handshake (with tcpdump) I see:
0x0000: 4500 0030 24da 0000 <= from plan9 to freebsd
0x0000: 4500 0030 d249 4000 <= from freebsd to plan9
Looks like FreeBSD always sets the DF (don't fragment) bit
(0x40 in byte 6), while plan9 doesn't (byte 6 is 0x00).
May be plan9 should set the DF (don't fragment) bit in the IP
header and try to do path MTU discovery? Either by default or
under some ctl option.
next prev parent reply other threads:[~2015-05-08 21:19 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-05-04 9:32 KADOTA Kyohei
2015-05-04 16:10 ` Anthony Sorace
2015-05-04 18:11 ` Aram Hăvărneanu
2015-05-04 18:51 ` David du Colombier
2015-05-05 14:29 ` Sergey Zhilkin
2015-05-05 15:05 ` Charles Forsyth
2015-05-05 15:38 ` David du Colombier
2015-05-05 22:23 ` Charles Forsyth
2015-05-05 22:29 ` cinap_lenrek
2015-05-05 22:33 ` David du Colombier
2015-05-05 22:53 ` Aram Hăvărneanu
2015-05-06 20:55 ` David du Colombier
2015-05-06 21:17 ` Charles Forsyth
2015-05-06 21:26 ` David du Colombier
2015-05-06 21:28 ` David du Colombier
2015-05-06 22:28 ` Charles Forsyth
2015-05-07 3:35 ` erik quanstrom
2015-05-07 6:15 ` David du Colombier
2015-05-07 13:17 ` erik quanstrom
2015-05-08 16:13 ` David du Colombier
2015-05-08 16:39 ` Charles Forsyth
2015-05-08 17:16 ` David du Colombier
2015-05-08 19:24 ` David du Colombier
2015-05-08 20:03 ` Steve Simon
2015-05-08 21:19 ` Bakul Shah [this message]
2015-05-09 14:43 ` erik quanstrom
2015-05-09 17:25 ` Lyndon Nerenberg
2015-05-09 17:30 ` Devon H. O'Dell
2015-05-09 17:35 ` Lyndon Nerenberg
2015-05-09 21:54 ` Devon H. O'Dell
2015-05-09 18:20 ` Bakul Shah
2015-05-09 3:11 ` cinap_lenrek
2015-05-09 5:59 ` lucio
2015-05-09 16:26 ` cinap_lenrek
2015-05-09 16:23 ` erik quanstrom
2015-05-10 4:55 ` erik quanstrom
2015-05-10 5:07 ` erik quanstrom
2015-05-10 17:57 ` David du Colombier
2015-05-10 20:18 ` erik quanstrom
2015-05-10 20:19 ` cinap_lenrek
2015-05-10 20:51 ` erik quanstrom
2015-05-10 21:34 ` cinap_lenrek
2015-05-11 1:23 ` erik quanstrom
2015-05-09 16:59 ` erik quanstrom
2015-05-06 22:35 ` Steven Stallion
2015-05-06 23:47 ` Charles Forsyth
2015-05-07 3:38 ` erik quanstrom
2015-05-07 3:43 ` erik quanstrom
2015-05-05 15:07 ` KADOTA Kyohei
2015-05-05 14:47 ` KADOTA Kyohei
2015-05-05 15:46 ` steve
2015-05-05 15:54 ` David du Colombier
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