From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wg0-f48.google.com (mail-wg0-f48.google.com [74.125.82.48]) by kanga.kvack.org (Postfix) with ESMTP id 3620A6B0032 for ; Sun, 25 Jan 2015 04:25:26 -0500 (EST) Received: by mail-wg0-f48.google.com with SMTP id x12so4357917wgg.7 for ; Sun, 25 Jan 2015 01:25:25 -0800 (PST) Received: from mx2.suse.de (cantor2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id u2si13074596wiw.38.2015.01.25.01.25.24 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Sun, 25 Jan 2015 01:25:24 -0800 (PST) Message-ID: <54C4B680.3010304@suse.cz> Date: Sun, 25 Jan 2015 10:25:20 +0100 From: Vlastimil Babka MIME-Version: 1.0 Subject: Re: [PATCH] mm: incorporate read-only pages into transparent huge pages References: <1421999256-3881-1-git-send-email-ebru.akagunduz@gmail.com> <20150123191816.GN11755@redhat.com> In-Reply-To: <20150123191816.GN11755@redhat.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Andrea Arcangeli , Ebru Akagunduz Cc: linux-mm@kvack.org, akpm@linux-foundation.org, kirill@shutemov.name, mhocko@suse.cz, mgorman@suse.de, rientjes@google.com, sasha.levin@oracle.com, hughd@google.com, hannes@cmpxchg.org, linux-kernel@vger.kernel.org, riel@redhat.com On 23.1.2015 20:18, Andrea Arcangeli wrote: >> >+ if (!pte_write(pteval)) { >> >+ if (++ro > khugepaged_max_ptes_none) >> >+ goto out_unmap; >> >+ } > It's true this is maxed out at 511, so there must be at least one > writable and not none pte (as results of the two "ro" and "none" > counters checks). Hm, but if we consider ro and pte_none separately, both can be lower than 512, but the sum of the two can be 512, so we can actually be in read-only VMA? -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org