linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Christoph Lameter <cl@linux.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
	Minchan Kim <minchan@kernel.org>,
	Pekka Enberg <penberg@kernel.org>,
	Joonsoo Kim <iamjoonsoo.kim@lge.com>,
	Michal Hocko <mhocko@suse.cz>,
	David Rientjes <rientjes@google.com>,
	linux-mm@kvack.org, linux-kernel@vger.kernel.org,
	sergey.senozhatsky.work@gmail.com, Joe Perches <joe@perches.com>
Subject: Re: [RFC][PATCH 0/5] do not dereference NULL pools in pools' destroy() functions
Date: Tue, 9 Jun 2015 20:11:25 -0500 (CDT)	[thread overview]
Message-ID: <alpine.DEB.2.11.1506092008220.3300@east.gentwo.org> (raw)
In-Reply-To: <20150609142523.b717dba6033ee08de997c8be@linux-foundation.org>

On Tue, 9 Jun 2015, Andrew Morton wrote:

> Well I like it, even though it's going to cause a zillion little cleanup
> patches.
>
> checkpatch already has a "kfree(NULL) is safe and this check is
> probably not required" test so I guess Joe will need to get busy ;)
>
> I'll park these patches until after 4.1 is released - it's getting to
> that time...

Why do this at all? I understand that kfree/kmem_cache_free can take a
null pointer but this is the destruction of a cache and it usually
requires multiple actions to clean things up and these actions have to be
properly sequenced. All other processors have to stop referencing this
cache before it can be destroyed. I think failing if someone does
something strange like doing cache destruction with a NULL pointer is
valuable.


  parent reply	other threads:[~2015-06-10  1:11 UTC|newest]

Thread overview: 44+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-06-09 12:04 [RFC][PATCH 0/5] do not dereference NULL pools in pools' destroy() functions Sergey Senozhatsky
2015-06-09 12:04 ` [RFC][PATCH 1/5] mm/slab_common: allow NULL cache pointer in kmem_cache_destroy() Sergey Senozhatsky
2015-06-17 23:14   ` David Rientjes
2015-06-17 23:52     ` Sergey Senozhatsky
2015-06-19 15:50       ` Julia Lawall
2015-08-06 14:21         ` Sergey Senozhatsky
2015-08-06 14:27           ` Julia Lawall
2015-08-06 14:29             ` Sergey Senozhatsky
2015-06-20 16:25       ` Julia Lawall
2015-07-16  8:26         ` Sergey Senozhatsky
2015-06-09 12:04 ` [RFC][PATCH 2/5] mm/mempool: allow NULL `pool' pointer in mempool_destroy() Sergey Senozhatsky
2015-06-17 23:21   ` David Rientjes
2015-06-17 23:54     ` Sergey Senozhatsky
2015-06-09 12:04 ` [RFC][PATCH 3/5] mm/dmapool: allow NULL `pool' pointer in dma_pool_destroy() Sergey Senozhatsky
2015-06-17 23:22   ` David Rientjes
2015-06-09 12:04 ` [RFC][PATCH 4/5] mm/zpool: allow NULL `zpool' pointer in zpool_destroy_pool() Sergey Senozhatsky
2015-06-10 20:59   ` Dan Streetman
2015-06-10 23:58     ` Sergey Senozhatsky
2015-06-11  0:48       ` Joe Perches
2015-06-11  0:59         ` Sergey Senozhatsky
2015-06-11  1:01           ` Dan Streetman
2015-06-09 12:04 ` [RFC][PATCH 5/5] mm/zsmalloc: allow NULL `pool' pointer in zs_destroy_pool() Sergey Senozhatsky
2015-06-09 21:25 ` [RFC][PATCH 0/5] do not dereference NULL pools in pools' destroy() functions Andrew Morton
2015-06-10  0:06   ` Joe Perches
2015-06-10  4:39     ` [PATCH] checkpatch: Add some <foo>_destroy functions to NEEDLESS_IF tests Joe Perches
2015-06-10  5:52       ` [PATCH V2] " Joe Perches
2015-06-10 10:18         ` Sergey Senozhatsky
2015-06-11  9:41         ` Julia Lawall
2015-06-11  9:51           ` Sergey Senozhatsky
2015-06-11  9:55             ` Julia Lawall
2015-07-14 23:03         ` Andrew Morton
2015-07-15  0:27           ` Sergey Senozhatsky
2015-06-10  5:46     ` [RFC][PATCH 0/5] do not dereference NULL pools in pools' destroy() functions Julia Lawall
2015-06-10  6:41       ` Sergey Senozhatsky
2015-06-10  6:44         ` Julia Lawall
2015-06-10  6:52           ` Sergey Senozhatsky
2015-06-10  1:11   ` Christoph Lameter [this message]
2015-06-10  1:51     ` Andrew Morton
2015-06-10  2:00       ` Christoph Lameter
2015-06-10  2:17         ` Andrew Morton
2015-06-10  4:47           ` Joe Perches
2015-06-11 17:26           ` Christoph Lameter
2015-06-11 17:40             ` Andrew Morton
2015-06-10  2:04     ` Sergey Senozhatsky

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=alpine.DEB.2.11.1506092008220.3300@east.gentwo.org \
    --to=cl@linux.com \
    --cc=akpm@linux-foundation.org \
    --cc=iamjoonsoo.kim@lge.com \
    --cc=joe@perches.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=mhocko@suse.cz \
    --cc=minchan@kernel.org \
    --cc=penberg@kernel.org \
    --cc=rientjes@google.com \
    --cc=sergey.senozhatsky.work@gmail.com \
    --cc=sergey.senozhatsky@gmail.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).