netdev - Re: cat /proc/net/tcp takes 0.5 seconds on x86

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20080827.164535.150037784.davem@davemloft.net>
Date:	Wed, 27 Aug 2008 16:45:35 -0700 (PDT)
From:	David Miller <davem@...emloft.net>
To:	dada1@...mosbay.com
Cc:	andi@...stfloor.org, davej@...hat.com, netdev@...r.kernel.org,
	j.w.r.degoede@....nl
Subject: Re: cat /proc/net/tcp takes 0.5 seconds on x86_64

From: Eric Dumazet <dada1@...mosbay.com>
Date: Thu, 28 Aug 2008 01:43:31 +0200

> David Miller a écrit :
> > From: Eric Dumazet <dada1@...mosbay.com>
> > Date: Thu, 28 Aug 2008 01:09:19 +0200
> > 
> >> Not really, I suspect commit (a7ab4b501f9b8a9dc4d5cee542db67b6ccd1088b [TCPv4]: Improve BH latency in /proc/net/tcp) is responsible for longer delays.
> >> Note that its rather old :
> >  ...
> >> We used to disable bh once, while reading the table. This sucked.
> >>
> >> In case machine is handling trafic, we now are preemptable by softirqs
> >> while reading /proc/net/tcp. Thats a good thing.
> > Yes, that would account for it, good spotting.
> > 
> >> By the way, I find Andi patch usefull. Same thing could be done for /proc/net/rt_cache.
> > Fair enough.  If you can cook up a quick rt_cache patch I'll toss it and
> > Andi's patch into net-next so it can cook for a while.
> 
> Well, first patch I would like to submit is about letting netlink being able to be faster than /proc/net/tcp again :)

Andi just posted a very similar patch :)
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html