From: Rik van Riel <riel@redhat.com>
To: Ying Han <yinghan@google.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>,
Minchan Kim <minchan.kim@gmail.com>,
Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>,
Balbir Singh <balbir@linux.vnet.ibm.com>,
Tejun Heo <tj@kernel.org>, Pavel Emelyanov <xemul@openvz.org>,
KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
Andrew Morton <akpm@linux-foundation.org>,
Li Zefan <lizf@cn.fujitsu.com>, Mel Gorman <mel@csn.ul.ie>,
Christoph Lameter <cl@linux.com>,
Johannes Weiner <hannes@cmpxchg.org>,
Hugh Dickins <hughd@google.com>, Michal Hocko <mhocko@suse.cz>,
Salman Qazi <sqazi@google.com>,
Dave Hansen <dave@linux.vnet.ibm.com>,
Zhu Yanhai <zhu.yanhai@gmail.com>,
linux-mm@kvack.org
Subject: Re: [PATCH] Eliminate task stack trace duplication.
Date: Tue, 03 May 2011 14:23:59 -0400 [thread overview]
Message-ID: <4DC0483F.50609@redhat.com> (raw)
In-Reply-To: <1304444135-14128-1-git-send-email-yinghan@google.com>
On 05/03/2011 01:35 PM, Ying Han wrote:
> The problem with small dmesg ring buffer like 512k is that only limited number
> of task traces will be logged. Sometimes we lose important information only
> because of too many duplicated stack traces.
I like it. I often overlook information from staring
myself blind on way too many duplicate stack traces.
> This patch tries to reduce the duplication of task stack trace in the dump
> message by hashing the task stack. The hashtable is a 32k pre-allocated buffer
> during bootup.
This changelog doesn't tell the whole story of what
the code does.
It appears to store stack traces in the table, and
use the hash to look them up. Somehow there's a global
pointer, called cur_stack, involved too.
The code looks correct, but somehow I'm not happy with
it. Having said that, I also don't have ideas on how to
make it better.
If nobody else knows how to make this code better, maybe
it should just be merged as is. I hope someone has ideas,
though :)
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next prev parent reply other threads:[~2011-05-03 18:24 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-05-03 17:35 [PATCH] Eliminate task stack trace duplication Ying Han
2011-05-03 18:23 ` Rik van Riel [this message]
2011-05-03 20:10 ` Ying Han
2011-05-03 19:50 ` Andi Kleen
2011-05-03 20:09 ` Ying Han
2011-05-03 21:10 ` Andi Kleen
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