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Date: Fri, 17 Nov 2017 09:35:21 -0800
From: Christoph Hellwig <hch@infradead.org>
To: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Minchan Kim <minchan@kernel.org>, Huang Ying <ying.huang@intel.com>,
        Mel Gorman <mgorman@techsingularity.net>,
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        Shakeel Butt <shakeelb@google.com>, Greg Thelen <gthelen@google.com>,
        linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/2] mm,vmscan: Kill global shrinker lock.
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On Tue, Nov 14, 2017 at 06:37:42AM +0900, Tetsuo Handa wrote:
> Since do_shrink_slab() can reschedule, we cannot protect shrinker_list
> using one RCU section. But using atomic_inc()/atomic_dec() for each
> do_shrink_slab() call will not impact so much.

But you could use SRCU..