From mboxrd@z Thu Jan  1 00:00:00 1970
From: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Subject: Re: [RFC][-mm] Add an owner to the mm_struct (v4)
Date: Wed, 2 Apr 2008 13:53:57 +0900
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Cc: Paul Menage <menage@google.com>, Pavel Emelianov <xemul@openvz.org>, Hugh Dickins <hugh@veritas.com>, Sudhir Kumar <skumar@linux.vnet.ibm.com>, YAMAMOTO Takashi <yamamoto@valinux.co.jp>, lizf@cn.fujitsu.com, linux-kernel@vger.kernel.org, taka@valinux.co.jp, linux-mm@kvack.org, David Rientjes <rientjes@google.com>, Andrew Morton <akpm@linux-foundation.org>
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On Wed, 02 Apr 2008 08:55:34 +0530
Balbir Singh <balbir@linux.vnet.ibm.com> wrote:

> > 
> >> +	/*
> >> +	 * Search through everything else. We should not get
> >> +	 * here often
> >> +	 */
> >> +	do_each_thread(g, c) {
> >> +		if (c->mm == mm)
> >> +			goto assign_new_owner;
> >> +	} while_each_thread(g, c);
> > 
> > Doing above in synchronized manner seems too heavy.
> > When this happen ? or Can this be done in lazy "on-demand" manner ?
> > 
> 
> Do you mean under task_lock()?
> 
No, scanning itself. 
How rarely this scan happens under a server which has 10000- threads ?

Thanks,
-Kame