linux-kernel - Re: bad networking related lag in v2.6.22-rc2

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]

Date:	Wed, 23 May 2007 11:10:43 +0530
From:	Anant Nitya <kernel@...chanda.info>
To:	linux-kernel@...r.kernel.org
Cc:	Ingo Molnar <mingo@...e.hu>, Patrick McHardy <kaber@...sh.net>,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Thomas Gleixner <tglx@...utronix.de>,
	"David S. Miller" <davem@...emloft.net>
Subject: Re: bad networking related lag in v2.6.22-rc2

On Tuesday 22 May 2007 11:52:33 Ingo Molnar wrote:
> * Anant Nitya <kernel@...chanda.info> wrote:
> > > I think I already found the bug, please try if this patch helps.
> >
> > Sorry, but this patch is not helping here. I recompiled the kernel
> > with this patch but same load pattern still make system to crawl.
> >
> > Here is the link for script I use to shape traffic.
> >
> > http://cybertek.info/taitai/adslbwopt.sh
>
> could you also apply the fix for the softirq problem below, to make sure
> it does not interact?
>
> 	Ingo
>
> Index: linux/kernel/sched.c
> ===================================================================
> --- linux.orig/kernel/sched.c
> +++ linux/kernel/sched.c
> @@ -4212,9 +4212,7 @@ int __sched cond_resched_softirq(void)
>  	BUG_ON(!in_softirq());
>
>  	if (need_resched() && system_state == SYSTEM_RUNNING) {
> -		raw_local_irq_disable();
> -		_local_bh_enable();
> -		raw_local_irq_enable();
> +		local_bh_enable();
>  		__cond_resched();
>  		local_bh_disable();
>  		return 1;

Hi Ingo
Above patch does solve __ soft_irq_pending __ problem. I am running this patch 
with kernel 2.6.21.1 since last day doing all kinda things but haven't 
encountered any __ NOHZ: local_softirq_pending __. But network lag that I am 
seeing since 2.6.22-rc1 is still there even with this patch applied. If you 
need any more information please do ask. Meanwhile I will do gitbisect as 
suggested by linus to find out the specific commit that introduced this 
problem and will inform once I find it. Its good to see system running 
without any __ local_softirq_problem __ :)

Regards
Ananitya

-- 
Out of many thousands, one may endeavor for perfection, and of
those who have achieved perfection, hardly one knows Me in truth.
				-- Gita Sutra Of Mysticism
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/