From: KOSAKI Motohiro <kosaki.motohiro@gmail.com>
To: David Rientjes <rientjes@google.com>
Cc: Dave Jones <davej@redhat.com>,
Linux Kernel <linux-kernel@vger.kernel.org>,
bhutchings@solarflare.com, linux-mm@kvack.org,
Linus Torvalds <torvalds@linux-foundation.org>,
Andrew Morton <akpm@linux-foundation.org>
Subject: Re: mpol_to_str revisited.
Date: Tue, 16 Oct 2012 19:39:29 -0400 [thread overview]
Message-ID: <CAHGf_=pemT6rcbu=dBVSJE7GuGWwVFP+Wn-mwkcsZ_gBGfaOsg@mail.gmail.com> (raw)
In-Reply-To: <alpine.DEB.2.00.1210152306320.9480@chino.kir.corp.google.com>
On Tue, Oct 16, 2012 at 2:10 AM, David Rientjes <rientjes@google.com> wrote:
> On Tue, 16 Oct 2012, KOSAKI Motohiro wrote:
>
>> >> I don't think 80de7c3138ee9fd86a98696fd2cf7ad89b995d0a is right fix.
>> >
>> > It's certainly not a complete fix, but I think it's a much better result
>> > of the race, i.e. we don't panic anymore, we simply fail the read()
>> > instead.
>>
>> Even though 80de7c3138ee9fd86a98696fd2cf7ad89b995d0a itself is simple. It bring
>> to caller complex. That's not good and have no worth.
>>
>
> Before: the kernel panics, all workloads cease.
> After: the file shows garbage, all workloads continue.
>
> This is better, in my opinion, but at best it's only a judgment call and
> has no effect on anything.
Kernel panics help to find our serious mistake.
> I agree it would be better to respect the return value of mpol_to_str()
> since there are other possible error conditions other than a freed
> mempolicy, but let's not consider reverting 80de7c3138. It is obviously
> not a full solution to the problem, though, and we need to serialize with
> task_lock().
Sorry no. I will have to revert it. mempolicy have already a lot of
meaningless complex and bring us a lot of problems. I haven't
seen any reason adding more.
> Dave, are you interested in coming up with a patch?
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next prev parent reply other threads:[~2012-10-16 23:39 UTC|newest]
Thread overview: 59+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-10-08 15:09 Dave Jones
2012-10-08 15:15 ` Dave Jones
2012-10-08 20:46 ` David Rientjes
2012-10-08 20:35 ` David Rientjes
2012-10-08 20:52 ` Dave Jones
2012-10-16 0:48 ` David Rientjes
2012-10-09 0:33 ` Ben Hutchings
2012-10-16 2:34 ` KOSAKI Motohiro
2012-10-16 3:58 ` David Rientjes
2012-10-16 5:10 ` KOSAKI Motohiro
2012-10-16 6:10 ` David Rientjes
2012-10-16 23:39 ` KOSAKI Motohiro [this message]
2012-10-17 0:12 ` David Rientjes
2012-10-17 0:31 ` [patch for-3.7] mm, mempolicy: fix printing stack contents in numa_maps David Rientjes
2012-10-17 1:38 ` KOSAKI Motohiro
2012-10-17 1:49 ` David Rientjes
2012-10-17 1:53 ` KOSAKI Motohiro
2012-10-17 4:05 ` Dave Jones
2012-10-17 5:24 ` David Rientjes
2012-10-17 5:42 ` Kamezawa Hiroyuki
2012-10-17 8:49 ` KOSAKI Motohiro
2012-10-17 19:50 ` David Rientjes
2012-10-17 21:05 ` KOSAKI Motohiro
2012-10-17 21:27 ` David Rientjes
2012-10-17 18:14 ` Dave Jones
2012-10-17 19:21 ` David Rientjes
2012-10-17 19:32 ` Dave Jones
2012-10-17 19:38 ` David Rientjes
2012-10-17 19:45 ` Dave Jones
2012-10-17 20:28 ` [patch for-3.7] mm, mempolicy: avoid taking mutex inside spinlock when reading numa_maps David Rientjes
2012-10-17 21:31 ` [patch for-3.7 v2] " David Rientjes
2012-10-18 4:06 ` Kamezawa Hiroyuki
2012-10-18 4:14 ` Linus Torvalds
2012-10-18 4:41 ` Kamezawa Hiroyuki
2012-10-18 4:34 ` Kamezawa Hiroyuki
2012-10-18 20:03 ` David Rientjes
2012-10-19 8:35 ` [patch for-3.7 v3] mm, mempolicy: hold task->mempolicy refcount while " Kamezawa Hiroyuki
2012-10-19 9:28 ` David Rientjes
2012-10-22 2:47 ` Kamezawa Hiroyuki
2012-10-22 20:55 ` Andrew Morton
2012-10-22 20:56 ` David Rientjes
2012-10-19 19:15 ` KOSAKI Motohiro
2012-10-19 6:51 ` [patch for-3.7 v2] mm, mempolicy: avoid taking mutex inside spinlock when " KOSAKI Motohiro
2012-10-18 4:35 ` David Rientjes
2012-10-24 23:30 ` [patch for-3.7] mm, mempolicy: fix printing stack contents in numa_maps Sasha Levin
2012-10-24 23:34 ` David Rientjes
2012-10-24 23:37 ` Sasha Levin
2012-10-25 0:08 ` David Rientjes
2012-10-25 0:54 ` KOSAKI Motohiro
2012-10-25 1:15 ` David Rientjes
2012-10-25 12:19 ` Peter Zijlstra
2012-10-25 14:39 ` Peter Zijlstra
2012-10-25 17:23 ` Sasha Levin
2012-10-25 20:22 ` David Rientjes
2012-10-25 23:09 ` Linus Torvalds
2012-10-26 8:48 ` Peter Zijlstra
2012-10-31 18:29 ` Sasha Levin
2012-11-21 0:59 ` Sasha Levin
2012-10-17 1:33 ` mpol_to_str revisited KOSAKI Motohiro
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