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Date:   Tue, 26 Mar 2019 14:36:04 +0100
From:   Oleg Nesterov <oleg@redhat.com>
To:     Christopher Lameter <cl@linux.com>
Cc:     Matthew Wilcox <willy@infradead.org>,
        Waiman Long <longman@redhat.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Pekka Enberg <penberg@kernel.org>,
        David Rientjes <rientjes@google.com>,
        Joonsoo Kim <iamjoonsoo.kim@lge.com>,
        linux-kernel@vger.kernel.org, linux-mm@kvack.org,
        selinux@vger.kernel.org, Paul Moore <paul@paul-moore.com>,
        Stephen Smalley <sds@tycho.nsa.gov>,
        Eric Paris <eparis@parisplace.org>,
        "Peter Zijlstra (Intel)" <peterz@infradead.org>
Subject: Re: [PATCH 2/4] signal: Make flush_sigqueue() use free_q to release
 memory
Message-ID: <20190326133603.GB16837@redhat.com>
References: <20190321214512.11524-1-longman@redhat.com>
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On 03/25, Christopher Lameter wrote:
>
> On Fri, 22 Mar 2019, Matthew Wilcox wrote:
>
> > Only for SLAB and SLUB.  SLOB requires that you pass a pointer to the
> > slab cache; it has no way to look up the slab cache from the object.
>
> Well then we could either fix SLOB to conform to the others or add a
> kmem_cache_free_rcu() variant.

Speaking of struct sigqueue we can simply use call_rcu() but see my previous
email, I am not sure this is the best option.

Oleg.