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charset=us-ascii Content-Disposition: inline In-Reply-To: <20190821160037.GK2263813@devbig004.ftw2.facebook.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-Bogosity: Ham, tests=bogofilter, spamicity=0.000044, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed, Aug 21, 2019 at 09:00:37AM -0700, Tejun Heo wrote: > > 2) When you invalidate frn entry here by writing 0 to 'at', it's likely to get > > reused soon. Possibly while the writeback is still running. And then you > > won't start any writeback for the new entry because of the > > atomic_read(&frn->done.cnt) == 1 check. This seems like it could happen > > pretty frequently? > > Hmm... yeah, the clearing might not make sense. I'll remove that. Oh, the reuse logic checks whether done.cnt == 1 and only reuse if no writeback is still in flight, so this one should be fine. Thanks. -- tejun