From: Qian Cai <cai@lca.pw>
To: Vlastimil Babka <vbabka@suse.cz>, akpm@linux-foundation.org
Cc: cl@linux.com, penberg@kernel.org, rientjes@google.com,
iamjoonsoo.kim@lge.com, linux-mm@kvack.org,
linux-kernel@vger.kernel.org,
"Tobin C. Harding" <tobin@kernel.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Michal Hocko <mhocko@kernel.org>
Subject: Re: [PATCH] slab: fix an infinite loop in leaks_show()
Date: Thu, 11 Apr 2019 07:08:23 -0400 [thread overview]
Message-ID: <02049855-d37f-965e-12f7-f2549cae73ec@lca.pw> (raw)
In-Reply-To: <43517646-a808-bccd-a05e-1b583fc411c7@suse.cz>
On 4/11/19 4:20 AM, Vlastimil Babka wrote:
> On 4/11/19 5:26 AM, Qian Cai wrote:
>> "cat /proc/slab_allocators" could hang forever on SMP machines with
>> kmemleak or object debugging enabled due to other CPUs running do_drain()
>> will keep making kmemleak_object or debug_objects_cache dirty and unable
>> to escape the first loop in leaks_show(),
>
> So what if we don't remove SLAB (yet?) but start removing the debugging
> functionality that has been broken for years and nobody noticed. I think
> Linus already mentioned that we remove at least the
> /proc/slab_allocators file...
In my experience, 2-year isn't that long for debugging features to be silently
broken with SLAB where kmemleak is broken for more than 4-year there. See
92d1d07daad6 ("mm/slab.c: kmemleak no scan alien caches").
prev parent reply other threads:[~2019-04-11 11:08 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-11 3:26 [PATCH] slab: fix an infinite loop in leaks_show() Qian Cai
2019-04-11 8:20 ` Vlastimil Babka
2019-04-11 11:08 ` Qian Cai [this message]
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