From: Chen Gang <gang.chen@asianux.com>
To: David Rientjes <rientjes@google.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com>,
KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>,
riel@redhat.com, hughd@google.com, xemul@parallels.com,
Wanpeng Li <liwanp@linux.vnet.ibm.com>,
Cyrill Gorcunov <gorcunov@gmail.com>,
linux-mm@kvack.org, Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCH v2] mm/shmem.c: check the return value of mpol_to_str()
Date: Wed, 18 Sep 2013 09:37:04 +0800 [thread overview]
Message-ID: <523903C0.6000609@asianux.com> (raw)
In-Reply-To: <alpine.DEB.2.02.1309171552141.21696@chino.kir.corp.google.com>
On 09/18/2013 06:53 AM, David Rientjes wrote:
> On Tue, 17 Sep 2013, Chen Gang wrote:
>
>>> BUG_ON() is safe. but I still don't like it. As far as I heard, Google
>>> changes BUG_ON as nop. So, BUG_ON(mpol_to_str() < 0) breaks google.
>>> Please treat an assertion as assertion. Not any other something.
>>>
>
> Google does not disable BUG_ON(), sheesh.
>
That sounds a good news.
>> Hmm... in kernel wide, BUG_ON() is 'common' 'standard' assertion, and
>> "mm/" is a common sub-system (not architecture specific), so when we
>> use BUG_ON(), we already 'express' our 'opinion' enough to readers.
>>
>
> That's ridiculous, we're not going to panic the kernel at runtime because
> a buffer is too small. Make it a compile-time error like I suggested so
> we catch this before we even build the kernel.
>
It seems not quite polite? ;-)
BUG_ON() is widely and commonly used in kernel wide, and BUG_ON() can be
customized by any architectures, so I guess, if google really think it
is necessary, it will customize it.
If "compile-time error" will make code complex to both readers and
writers (e.g. our case), forcing "compile-time error" may still be good
enough to google, but may not be good enough for others.
So in my opinion, for our case which is a common sub-system, not an
architecture specific sub-system, better use "run-time error".
Thanks.
--
Chen Gang
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next prev parent reply other threads:[~2013-09-18 1:38 UTC|newest]
Thread overview: 61+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-08-20 3:56 [PATCH 0/3] mm: mempolicy: the failure processing about mpol_to_str() Chen Gang
2013-08-20 3:57 ` [PATCH 1/3] mm/mempolicy.c: still fill buffer as full as possible when buffer space is not enough in mpol_to_str() Chen Gang
2013-08-20 3:58 ` [PATCH 2/3] fs/proc/task_mmu.c: check the return value of mpol_to_str() Chen Gang
2013-08-20 3:59 ` [PATCH 3/3] mm/shmem.c: " Chen Gang
2013-08-20 5:30 ` [PATCH 0/3] mm: mempolicy: the failure processing about mpol_to_str() Cyrill Gorcunov
2013-08-20 5:41 ` Chen Gang
2013-08-20 6:47 ` Cyrill Gorcunov
2013-08-20 7:48 ` Chen Gang
2013-08-20 7:51 ` Chen Gang
2013-08-20 8:09 ` Chen Gang
2013-08-20 8:13 ` Chen Gang F T
2013-08-20 8:20 ` Chen Gang
2013-08-20 8:25 ` Cyrill Gorcunov
2013-08-20 8:31 ` Chen Gang
2013-08-21 2:21 ` [PATCH 0/3] mm: shmem: check the return value of mpol_to_str() Chen Gang
2013-08-21 2:22 ` [PATCH 1/3] fs/proc/task_mmu.c: " Chen Gang
2013-08-21 2:23 ` [PATCH 2/3] mm/shmem.c: let shmem_show_mpol() return value Chen Gang
2013-08-21 2:24 ` [PATCH 3/3] mm/shmem.c: check the return value of mpol_to_str() Chen Gang
2013-08-21 22:03 ` [PATCH 2/3] mm/shmem.c: let shmem_show_mpol() return value Andrew Morton
2013-08-22 0:52 ` Chen Gang
2013-08-22 1:04 ` [PATCH] mm/shmem.c: check the return value of mpol_to_str() Chen Gang
2013-09-03 5:32 ` Chen Gang
2013-09-05 0:24 ` [PATCH v2] " Chen Gang
2013-09-09 20:30 ` David Rientjes
2013-09-10 0:47 ` Chen Gang
2013-09-10 6:43 ` David Rientjes
2013-09-10 7:01 ` Chen Gang
2013-09-12 0:33 ` David Rientjes
2013-09-12 2:19 ` KOSAKI Motohiro
2013-09-12 3:13 ` Chen Gang
2013-09-13 21:12 ` David Rientjes
2013-09-14 2:51 ` KOSAKI Motohiro
2013-09-16 3:27 ` Chen Gang
2013-09-16 20:13 ` David Rientjes
2013-09-17 0:45 ` Chen Gang
2013-09-17 22:51 ` David Rientjes
2013-09-18 1:20 ` Chen Gang
2013-09-12 3:02 ` Chen Gang
2013-09-12 18:19 ` KOSAKI Motohiro
2013-09-13 2:23 ` Chen Gang
2013-09-13 16:50 ` KOSAKI Motohiro
2013-09-16 2:55 ` Chen Gang
2013-09-16 16:16 ` KOSAKI Motohiro
2013-09-17 1:10 ` Chen Gang
2013-09-17 22:53 ` David Rientjes
2013-09-18 1:37 ` Chen Gang [this message]
2013-09-18 22:17 ` David Rientjes
2013-09-13 21:14 ` David Rientjes
2013-09-16 3:17 ` Chen Gang
2013-09-25 2:58 ` [patch] mm, mempolicy: make mpol_to_str robust and always succeed David Rientjes
2013-09-25 3:11 ` Dave Jones
2013-09-25 3:18 ` David Rientjes
2013-09-25 3:25 ` Dave Jones
2013-09-25 17:58 ` David Rientjes
2013-09-25 21:30 ` Andrew Morton
2013-09-25 22:06 ` David Rientjes
2013-08-21 5:31 ` [PATCH 0/3] mm: shmem: check the return value of mpol_to_str() Cyrill Gorcunov
2013-08-21 5:48 ` Chen Gang
2013-09-19 0:31 [PATCH v2] mm/shmem.c: " Chen,Gang( 陈刚)
[not found] <20130919003142.B72EC1840296@intranet.asianux.com>
2013-09-23 21:46 ` David Rientjes
2013-09-24 2:28 ` Chen Gang
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