From: Matt Mackall <mpm@selenic.com>
To: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@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, 01 Apr 2010 02:09:31 -0500 [thread overview]
Message-ID: <1270105771.3552.1143.camel@calx> (raw)
In-Reply-To: <20100401153428.d49c6345.kamezawa.hiroyu@jp.fujitsu.com>
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.
--
http://selenic.com : development and support for Mercurial and Linux
next prev parent reply other threads:[~2010-04-01 7:09 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-03-31 17:23 [PATCH] proc: pagemap: Hold mmap_sem during page walk 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 [this message]
2010-04-01 7:21 ` KOSAKI Motohiro
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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