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[209.85.220.65]) by mx.google.com with SMTPS id o39sor4539826pjb.10.2019.07.10.14.51.52 for (Google Transport Security); Wed, 10 Jul 2019 14:51:52 -0700 (PDT) Received-SPF: pass (google.com: domain of henryburns@google.com designates 209.85.220.65 as permitted sender) client-ip=209.85.220.65; Authentication-Results: mx.google.com; dkim=pass header.i=@google.com header.s=20161025 header.b=pMiktFKk; spf=pass (google.com: domain of henryburns@google.com designates 209.85.220.65 as permitted sender) smtp.mailfrom=henryburns@google.com; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=google.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=4raB3IqyErqkg+JW+87rFy9oaXPi9i1d2UYtDB+hVu8=; b=pMiktFKkY/frqdyoQe7sXxn6LL1Cu1eJU2aCdvxnAIjKEfBMVT2/a7GBTubBVbfWa+ VrkYciVMRwRGNBsyxWRacUlQbz9KrF+YgOEQ71hxJjkKxT2GbmMOnuU6hw3Edpz1rbCX TVaEQ4RgH61os6AyO9go6PMGvQHfA26T17tshvtfCu+Y4EWNOD1RFFj6LJF3db0kSaGw 8Y52qRyryah4clumr06EeeGgyEUDxNrK5Yj8CqCVoefgScQMSh511m0RPf+Ki7n+w5rf lcuyhHFh80YdhFGhsoBdDpij2xLcvg2j6MpWyUseC13csarlkuF/J5ijYVFflfpMRiG4 GUig== X-Google-Smtp-Source: APXvYqzpotPnFgfn8F3Q6TpCTjeRegyu0pJeMseHXkiht1BvBEBtrWB5K160JbdnR1FiaSX66t4gclal9uiAjRoVwZs= X-Received: by 2002:a17:90a:380d:: with SMTP id w13mr620824pjb.138.1562795512264; Wed, 10 Jul 2019 14:51:52 -0700 (PDT) MIME-Version: 1.0 References: <20190710213238.91835-1-henryburns@google.com> In-Reply-To: From: Henry Burns Date: Wed, 10 Jul 2019 14:51:16 -0700 Message-ID: Subject: Re: [PATCH] mm/z3fold.c: remove z3fold_migration trylock To: Shakeel Butt Cc: Vitaly Wool , Andrew Morton , Vitaly Vul , Jonathan Adams , Greg Kroah-Hartman , Snild Dolkow , Thomas Gleixner , Linux MM , LKML Content-Type: text/plain; charset="UTF-8" X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: > > z3fold_page_migrate() will never succeed because it attempts to acquire a > > lock that has already been taken by migrate.c in __unmap_and_move(). > > > > __unmap_and_move() migrate.c > > trylock_page(oldpage) > > move_to_new_page(oldpage_newpage) > > a_ops->migrate_page(oldpage, newpage) > > z3fold_page_migrate(oldpage, newpage) > > trylock_page(oldpage) > > > > > > Signed-off-by: Henry Burns > > Reviewed-by: Shakeel Butt > > Please add the Fixes tag as well. Fixes: 1f862989b04a ("mm/z3fold.c: support page migration") > > > --- > > mm/z3fold.c | 6 ------ > > 1 file changed, 6 deletions(-) > > > > diff --git a/mm/z3fold.c b/mm/z3fold.c > > index 985732c8b025..9fe9330ab8ae 100644 > > --- a/mm/z3fold.c > > +++ b/mm/z3fold.c > > @@ -1335,16 +1335,11 @@ static int z3fold_page_migrate(struct address_space *mapping, struct page *newpa > > zhdr = page_address(page); > > pool = zhdr_to_pool(zhdr); > > > > - if (!trylock_page(page)) > > - return -EAGAIN; > > - > > if (!z3fold_page_trylock(zhdr)) { > > - unlock_page(page); > > return -EAGAIN; > > } > > if (zhdr->mapped_count != 0) { > > z3fold_page_unlock(zhdr); > > - unlock_page(page); > > return -EBUSY; > > } > > new_zhdr = page_address(newpage); > > @@ -1376,7 +1371,6 @@ static int z3fold_page_migrate(struct address_space *mapping, struct page *newpa > > queue_work_on(new_zhdr->cpu, pool->compact_wq, &new_zhdr->work); > > > > page_mapcount_reset(page); > > - unlock_page(page); > > put_page(page); > > return 0; > > } > > -- > > 2.22.0.410.gd8fdbe21b5-goog > >