From: Stefani Seibold <stefani@seibold.net>
To: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: LKML <linux-kernel@vger.kernel.org>, Ingo Molnar <mingo@elte.hu>,
Peter Zijlstra <a.p.zijlstra@chello.nl>,
Alexey Dobriyan <adobriyan@gmail.com>,
"Eric W. Biederman" <ebiederm@xmission.com>,
Randy Dunlap <randy.dunlap@oracle.com>,
Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCH] proc: revert to show stack information in /proc/{pid}/status
Date: Thu, 31 Dec 2009 16:48:14 +0100 [thread overview]
Message-ID: <1262274494.14143.7.camel@wall-e> (raw)
In-Reply-To: <20091231231051.1A1B.A69D9226@jp.fujitsu.com>
Am Donnerstag, den 31.12.2009, 23:12 +0900 schrieb KOSAKI Motohiro:
> Commit d899bf7b (procfs: provide stack information for threads) introduced
> to show stack information in /proc/{pid}/status. But it cause large performance
> regression. Unfortunately /proc/{pid}/status is used ps command too and ps is
> one of most important component. Because both to take mmap_sem and page table walk
> are heavily operation.
>
/proc/<pid>/status is IMHO not a performance relevant thing. The main
reason is to provide exact information about a running process.
> Thus, this patch revert it. Fortunately /proc/{pid}/task/{tid}/smaps
> provide almost same information. we can use it.
>
Completely wrong. Where does smaps provides this kind of information?
Where is there the high water mark of the stack usage?
> Cc: Stefani Seibold <stefani@seibold.net>
> Cc: Ingo Molnar <mingo@elte.hu>
> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
> Cc: Alexey Dobriyan <adobriyan@gmail.com>
> Cc: "Eric W. Biederman" <ebiederm@xmission.com>
> Cc: Randy Dunlap <randy.dunlap@oracle.com>
> Cc: Andrew Morton <akpm@linux-foundation.org>
> Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
> ---
Nak: Stefani Seibold <stefani@seibold.net>
next prev parent reply other threads:[~2009-12-31 15:48 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-12-31 14:12 [PATCH] proc: revert to show stack information in /proc/{pid}/status KOSAKI Motohiro
2009-12-31 15:48 ` Stefani Seibold [this message]
2010-01-01 14:14 ` KOSAKI Motohiro
2010-01-01 15:10 ` Stefani Seibold
2010-01-01 22:05 ` Samuel Thibault
2010-01-01 22:21 ` Stefani Seibold
2010-01-02 5:53 ` KOSAKI Motohiro
2010-01-02 8:26 ` Stefani Seibold
2010-01-02 14:05 ` [PATCH] partial revert to show stack information in /proc/<pid>/status Stefani Seibold
2010-01-05 5:24 ` KOSAKI Motohiro
2010-01-02 1:42 ` [PATCH] proc: revert to show stack information in /proc/{pid}/status Andi Kleen
2010-01-01 15:49 ` Andi Kleen
2010-01-01 16:09 ` Stefani Seibold
2010-01-07 21:52 ` Andrew Morton
2010-01-08 0:21 ` KOSAKI Motohiro
2010-01-08 0:34 ` Andrew Morton
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