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From: Anirban Sinha <ani@anirban.org>
To: Oleg Nesterov <oleg@redhat.com>
Cc: linux-kernel@vger.kernel.org, David Miller <davem@davemloft.net>,
	netdev@vger.kernel.org, Anirban Sinha <asinha@zeugmasystems.com>
Subject: Re: Kernel oops when clearing bgp neighbor info with TCP MD5SUM enabled
Date: Mon, 19 Oct 2009 08:32:07 -0700	[thread overview]
Message-ID: <4ADC8677.7000607@anirban.org> (raw)
In-Reply-To: <20091019121327.GA11423@redhat.com>



Once upon a time, like on 09-10-19 5:13 AM, Oleg Nesterov wrote:
> Hi Anirban,
> 
> On 10/18, Anirban Sinha wrote:
>>
>> I have a question for you. The queue_work() routine which is called from
>> schedule_work() does a put_cpu() which in turn does a enable_preempt(). Is
>> this an attempt to trigger the scheduler?
> 
> No. please note that queue_work() does get_cpu() + put_cpu() to protect
> against cpu_down() in between.

grrr! Ah yes, my eyes failed me (or it saw what I wanted it to see :)). You do have a get_cpu() and put_cpu() together in the same code path. I guess I will have to keep looking at inet_twdr_hangman(). 

>> Is is
>> it illegal to schedule a work function from within a timer callback?
> 
> Yes sure.

hmm. may be in that case, that function needs to be re-written. 

> I'd suppose that this unbalance comes from inet_twdr_hangman() pathes.
> 
> Could you verify this?

I'll keep looking. Thanks for the help Oleg. 

Ani


  reply	other threads:[~2009-10-19 15:32 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-10-08 22:19 Kernel oops when clearing bgp neighbor info with TCP MD5SUM enabled Anirban Sinha
2009-10-08 22:54 ` David Miller
2009-10-08 23:33   ` Anirban Sinha
2009-10-09  0:57     ` David Miller
2009-10-17 17:57       ` Anirban Sinha
2009-10-18  2:35         ` Anirban Sinha
2009-10-18 20:19           ` Anirban Sinha
2009-10-18 20:19             ` Anirban Sinha
2009-10-19 12:13             ` Oleg Nesterov
2009-10-19 15:32               ` Anirban Sinha [this message]
2009-10-19 15:36                 ` Oleg Nesterov
2009-10-19 16:01                   ` Anirban Sinha
2009-10-20  0:56               ` Anirban Sinha
2009-10-20  1:08                 ` [PATCH] " Anirban Sinha
2009-10-20  1:13                   ` David Miller
2009-10-20  1:17                     ` Anirban Sinha

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