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From: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
To: Matt Mackall <mpm@selenic.com>
Cc: kosaki.motohiro@jp.fujitsu.com,
	KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	San Mehat <san@google.com>,
	linux-kernel@vger.kernel.org,
	Brian Swetland <swetland@google.com>,
	Dave Hansen <haveblue@us.ibm.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	n-horiguchi@ah.jp.nec.com
Subject: Re: [PATCH] proc: pagemap: Hold mmap_sem during page walk
Date: Thu,  1 Apr 2010 16:21:16 +0900 (JST)	[thread overview]
Message-ID: <20100401161927.BE4F.A69D9226@jp.fujitsu.com> (raw)
In-Reply-To: <1270105771.3552.1143.camel@calx>

> On Thu, 2010-04-01 at 15:34 +0900, KAMEZAWA Hiroyuki wrote:
> > On Thu, 1 Apr 2010 15:09:56 +0900
> > KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> wrote:
> > 
> > >
> > > +		pm.pos = 0;
> > > +		start_vaddr += PAGEMAP_WALK_SIZE;
> > > +		end = start_vaddr + PAGEMAP_WALK_SIZE;
> > 
> > Sigh...this is bad..
> > 
> > ==
> > From: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
> > 
> > In initial design, walk_page_range() was designed just for walking page table and
> > it didn't require mmap_sem. Now, find_vma() etc.. are used in walk_page_range()
> > and we need mmap_sem around it.
> 
> This looks pretty reasonable. However, it also looks very similar to my
> first version of pagemap (which started with double-buffering). It's
> going to need re-testing to make sure it hasn't reintroduced any
> wrapping, alignment, or off-by-one bugs that have already been ironed
> out once or twice.

OK, I'm looking for your test result. :)

Thanks matt for your contribution!



  reply	other threads:[~2010-04-01  7:21 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-03-31 17:23 San Mehat
2010-03-31 17:54 ` Linus Torvalds
2010-03-31 21:40   ` Matt Mackall
2010-04-01  1:33     ` Linus Torvalds
2010-04-01  2:10       ` KOSAKI Motohiro
2010-04-01  3:20       ` Matt Mackall
2010-04-01  4:27         ` Linus Torvalds
2010-04-01  5:54         ` KOSAKI Motohiro
2010-04-01  5:55           ` KAMEZAWA Hiroyuki
2010-04-01  6:05             ` KOSAKI Motohiro
2010-04-01  6:09               ` KAMEZAWA Hiroyuki
2010-04-01  6:34                 ` KAMEZAWA Hiroyuki
2010-04-01  7:09                   ` Matt Mackall
2010-04-01  7:21                     ` KOSAKI Motohiro [this message]
2010-04-01 15:10                   ` Linus Torvalds
2010-04-02  0:11                     ` KAMEZAWA Hiroyuki
2010-04-02 14:30                       ` Matt Mackall
2010-04-06  6:48                         ` KAMEZAWA Hiroyuki

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