From: Matthew Wilcox <willy@infradead.org>
To: Catalin Marinas <catalin.marinas@arm.com>
Cc: Michal Hocko <mhocko@kernel.org>, Qian Cai <cai@lca.pw>,
akpm@linux-foundation.org, cl@linux.com, penberg@kernel.org,
rientjes@google.com, iamjoonsoo.kim@lge.com, linux-mm@kvack.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v4] kmemleak: survive in a low-memory situation
Date: Wed, 27 Mar 2019 11:21:58 -0700 [thread overview]
Message-ID: <20190327182158.GS10344@bombadil.infradead.org> (raw)
In-Reply-To: <20190327172955.GB17247@arrakis.emea.arm.com>
On Wed, Mar 27, 2019 at 05:29:57PM +0000, Catalin Marinas wrote:
> On Wed, Mar 27, 2019 at 09:44:32AM +0100, Michal Hocko wrote:
> > As long as there is an implicit __GFP_NOFAIL then kmemleak is simply
> > broken no matter what other gfp flags you play with. Has anybody looked
> > at some sort of preallocation where gfpflags_allow_blocking context
> > allocate objects into a pool that non-sleeping allocations can eat from?
>
> Quick attempt below and it needs some more testing (pretty random pick
> of the EMERGENCY_POOL_SIZE value). Also, with __GFP_NOFAIL removed, are
> the other flags safe or we should trim them further?
Why not use mempool?
> #define gfp_kmemleak_mask(gfp) (((gfp) & (GFP_KERNEL | GFP_ATOMIC)) | \
> __GFP_NORETRY | __GFP_NOMEMALLOC | \
> - __GFP_NOWARN | __GFP_NOFAIL)
> + __GFP_NOWARN)
Why GFP_NORETRY? And if I have specified one of the other retry policies
in my gfp flags, you should presumably clear that off before setting
GFP_NORETRY.
next prev parent reply other threads:[~2019-03-27 18:22 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-27 0:59 [PATCH v4] kmemleak: survive in a low-memory situation Qian Cai
2019-03-27 8:44 ` Michal Hocko
2019-03-27 11:34 ` Qian Cai
2019-03-27 11:44 ` Michal Hocko
2019-03-27 13:05 ` Qian Cai
2019-03-27 13:17 ` Michal Hocko
2019-03-27 17:29 ` Catalin Marinas
2019-03-27 18:02 ` Qian Cai
2019-03-28 15:05 ` Catalin Marinas
2019-03-28 15:41 ` Qian Cai
2019-03-27 18:17 ` Michal Hocko
2019-03-27 18:21 ` Matthew Wilcox [this message]
2019-03-28 14:59 ` Catalin Marinas
2019-03-28 15:24 ` Qian Cai
2019-03-29 12:02 ` Michal Hocko
2019-03-29 16:16 ` Catalin Marinas
2019-04-01 20:12 ` Michal Hocko
2019-04-05 16:43 ` Catalin Marinas
2019-03-28 6:05 ` Pekka Enberg
2019-03-28 10:30 ` Catalin Marinas
2019-03-28 11:50 ` Pekka Enberg
2019-03-28 15:28 ` Catalin Marinas
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