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From:   Shakeel Butt <shakeelb@google.com>
Date:   Tue, 25 Jun 2019 11:33:23 -0700
Message-ID: <CALvZod7EZYZJR68dqKF7V9xdgeYo8YnssR94O5zku9qii+xJPA@mail.gmail.com>
Subject: Re: [PATCH v7 07/10] mm: synchronize access to kmem_cache dying flag
 using a spinlock
To:     Roman Gushchin <guro@fb.com>
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        Vladimir Davydov <vdavydov.dev@gmail.com>,
        Linux MM <linux-mm@kvack.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Kernel Team <kernel-team@fb.com>,
        Johannes Weiner <hannes@cmpxchg.org>,
        Waiman Long <longman@redhat.com>
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On Tue, Jun 11, 2019 at 4:18 PM Roman Gushchin <guro@fb.com> wrote:
>
> Currently the memcg_params.dying flag and the corresponding
> workqueue used for the asynchronous deactivation of kmem_caches
> is synchronized using the slab_mutex.
>
> It makes impossible to check this flag from the irq context,
> which will be required in order to implement asynchronous release
> of kmem_caches.
>
> So let's switch over to the irq-save flavor of the spinlock-based
> synchronization.
>
> Signed-off-by: Roman Gushchin <guro@fb.com>

Reviewed-by: Shakeel Butt <shakeelb@google.com>