From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qg0-f72.google.com (mail-qg0-f72.google.com [209.85.192.72]) by kanga.kvack.org (Postfix) with ESMTP id 84CB46B0005 for ; Mon, 23 May 2016 14:49:20 -0400 (EDT) Received: by mail-qg0-f72.google.com with SMTP id k63so104053311qgf.2 for ; Mon, 23 May 2016 11:49:20 -0700 (PDT) Received: from mx1.redhat.com (mx1.redhat.com. [209.132.183.28]) by mx.google.com with ESMTPS id k5si25508593qke.143.2016.05.23.11.49.19 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 23 May 2016 11:49:19 -0700 (PDT) Message-ID: <1464029349.16365.58.camel@redhat.com> Subject: Re: [PATCH 3/3] mm, thp: make swapin readahead under down_read of mmap_sem From: Rik van Riel Date: Mon, 23 May 2016 14:49:09 -0400 In-Reply-To: <20160523184246.GE32715@dhcp22.suse.cz> References: <1464023651-19420-1-git-send-email-ebru.akagunduz@gmail.com> <1464023651-19420-4-git-send-email-ebru.akagunduz@gmail.com> <20160523184246.GE32715@dhcp22.suse.cz> Content-Type: multipart/signed; micalg="pgp-sha256"; protocol="application/pgp-signature"; boundary="=-2S8Xrnv2jDBKk5tnJv6n" Mime-Version: 1.0 Sender: owner-linux-mm@kvack.org List-ID: To: Michal Hocko , Ebru Akagunduz Cc: linux-mm@kvack.org, hughd@google.com, akpm@linux-foundation.org, kirill.shutemov@linux.intel.com, n-horiguchi@ah.jp.nec.com, aarcange@redhat.com, iamjoonsoo.kim@lge.com, gorcunov@openvz.org, linux-kernel@vger.kernel.org, mgorman@suse.de, rientjes@google.com, vbabka@suse.cz, aneesh.kumar@linux.vnet.ibm.com, hannes@cmpxchg.org, boaz@plexistor.com --=-2S8Xrnv2jDBKk5tnJv6n Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Mon, 2016-05-23 at 20:42 +0200, Michal Hocko wrote: > On Mon 23-05-16 20:14:11, Ebru Akagunduz wrote: > >=20 > > Currently khugepaged makes swapin readahead under > > down_write. This patch supplies to make swapin > > readahead under down_read instead of down_write. > You are still keeping down_write. Can we do without it altogether? > Blocking mmap_sem of a remote proces for write is certainly not nice. Maybe Andrea can explain why khugepaged requires a down_write of mmap_sem? If it were possible to have just down_read that would make the code a lot simpler. --=20 All Rights Reversed. --=-2S8Xrnv2jDBKk5tnJv6n Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part Content-Transfer-Encoding: 7bit -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQEcBAABCAAGBQJXQ1CmAAoJEM553pKExN6DrMUH/05e6zsWP2ZtM1UisbmtX31w +et8QpB8scRtyKvyrCgp/TJHyGpEQuExm4xli2lo35gld+ghdXb1eKzWFi1s66iW WQKsozVBoMAflRC5TDZf3rQoOfNDkHb9NGzzazRZklNdJl4wZhTUoaJ7hM1m8Wj1 L6wH3XUe3PMlPx7mBhZKj0hZ6GM3AAkaK+LrbjPf/hLP9XDPQMJHDi4hizOM8hCy 4Kid0RX1UFctwu3Pf99Lr/GkIUWZNZocXEzCObZ9s/6cc33ZqNBjoSbjUEX+pW1C a52bAOfslafFKPeftBdof/HD+Ru5XX6UNAjH6Y4Igt42vNRmdCF9kRlYXH8vrjs= =1wFg -----END PGP SIGNATURE----- --=-2S8Xrnv2jDBKk5tnJv6n-- -- 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