linux-kernel - Re: [PATCH] mm: disallow direct reclaim page writeback

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20100414054144.GH2493@dastard>
Date:	Wed, 14 Apr 2010 15:41:44 +1000
From:	Dave Chinner <david@...morbit.com>
To:	KAMEZAWA Hiroyuki <kamezawa.hiroyu@...fujitsu.com>
Cc:	Chris Mason <chris.mason@...cle.com>, Mel Gorman <mel@....ul.ie>,
	linux-kernel@...r.kernel.org, linux-mm@...ck.org,
	linux-fsdevel@...r.kernel.org
Subject: Re: [PATCH] mm: disallow direct reclaim page writeback

On Wed, Apr 14, 2010 at 01:59:45PM +0900, KAMEZAWA Hiroyuki wrote:
> On Wed, 14 Apr 2010 11:40:41 +1000
> Dave Chinner <david@...morbit.com> wrote:
> 
> >  50)     3168      64   xfs_vm_writepage+0xab/0x160 [xfs]
> >  51)     3104     384   shrink_page_list+0x65e/0x840
> >  52)     2720     528   shrink_zone+0x63f/0xe10
> 
> A bit OFF TOPIC.
> 
> Could you share disassemble of shrink_zone() ?
> 
> In my environ.
> 00000000000115a0 <shrink_zone>:
>    115a0:       55                      push   %rbp
>    115a1:       48 89 e5                mov    %rsp,%rbp
>    115a4:       41 57                   push   %r15
>    115a6:       41 56                   push   %r14
>    115a8:       41 55                   push   %r13
>    115aa:       41 54                   push   %r12
>    115ac:       53                      push   %rbx
>    115ad:       48 83 ec 78             sub    $0x78,%rsp
>    115b1:       e8 00 00 00 00          callq  115b6 <shrink_zone+0x16>
>    115b6:       48 89 75 80             mov    %rsi,-0x80(%rbp)
> 
> disassemble seems to show 0x78 bytes for stack. And no changes to %rsp
> until retrun.

I see the same. I didn't compile those kernels, though. IIUC,
they were built through the Ubuntu build infrastructure, so there is
something different in terms of compiler, compiler options or config
to what we are both using. Most likely it is the compiler inlining,
though Chris's patches to prevent that didn't seem to change the
stack usage.

I'm trying to get a stack trace from the kernel that has shrink_zone
in it, but I haven't succeeded yet....

Cheers,

Dave.
-- 
Dave Chinner
david@...morbit.com
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/