From nobody Mon Nov 17 03:44:25 2025 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=pass(p=none dis=none) header.from=nongnu.org ARC-Seal: i=1; a=rsa-sha256; t=1602525199; cv=none; d=zohomail.com; s=zohoarc; b=a7CusIV4omAOtxvC5PYosxSAhkE7HCvcg6d1Opg6ssdTGc7IlS2zdkVcoKMkRsw12G4K+cJZ3zpg66LEmJ6zB5lZ/RcujpkTshrlXahB8Xi4CxdspF547bTVvAcVtLb3npRgM393qSM1/xcn3Q+mGf+srYSvFWFr/7vxRTOIjX8= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1602525199; h=Cc:Date:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:Message-ID:Reply-To:References:Sender:Subject:To; bh=Pr13xDv11DEQovrWewmn4LAeTZQKFqqbYv7NU+b3iK0=; b=iFBAI0JR8vVndHIJW2/UzSZOY3N08ZhE6jhKT6hOtOzZUxPkgBJedVGJkHKz+AMg39VrtsHJtdI0gS3WJ5URpvj8hZodq4qltFmWt2VahI3nKLu+YJl7BTyY++Kyx5N0yOjBPp3NORYdy43RQS8A4Ms1nyCbleoexlCz8EDtPpM= ARC-Authentication-Results: i=1; mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=pass header.from= (p=none dis=none) header.from= Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1602525199782286.4127626502782; Mon, 12 Oct 2020 10:53:19 -0700 (PDT) Received: from localhost ([::1]:49020 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kS20c-0000PH-1K for importer@patchew.org; Mon, 12 Oct 2020 13:53:18 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:59858) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kS1yu-0006JI-D3; Mon, 12 Oct 2020 13:51:32 -0400 Received: from relay.sw.ru ([185.231.240.75]:34398 helo=relay3.sw.ru) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kS1yq-00086o-5t; Mon, 12 Oct 2020 13:51:32 -0400 Received: from [172.16.25.136] (helo=localhost.sw.ru) by relay3.sw.ru with esmtp (Exim 4.94) (envelope-from ) id 1kS1xu-0047iC-3A; Mon, 12 Oct 2020 20:50:30 +0300 To: qemu-block@nongnu.org Cc: qemu-devel@nongnu.org, kwolf@redhat.com, mreitz@redhat.com, fam@euphon.net, stefanha@redhat.com, armbru@redhat.com, jsnow@redhat.com, libvir-list@redhat.com, eblake@redhat.com, den@openvz.org, vsementsov@virtuozzo.com, andrey.shinkevich@virtuozzo.com Subject: [PATCH v11 09/13] copy-on-read: skip non-guest reads if no copy needed Date: Mon, 12 Oct 2020 20:43:21 +0300 Message-Id: <1602524605-481160-10-git-send-email-andrey.shinkevich@virtuozzo.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1602524605-481160-1-git-send-email-andrey.shinkevich@virtuozzo.com> References: <1602524605-481160-1-git-send-email-andrey.shinkevich@virtuozzo.com> Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=185.231.240.75; envelope-from=andrey.shinkevich@virtuozzo.com; helo=relay3.sw.ru X-detected-operating-system: by eggs.gnu.org: First seen = 2020/10/12 13:44:17 X-ACL-Warn: Detected OS = Linux 3.11 and newer [fuzzy] X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" Reply-to: Andrey Shinkevich From: Andrey Shinkevich via Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" If the flag BDRV_REQ_PREFETCH was set, pass it further to the COR-driver to skip unneeded reading. It can be taken into account for the COR-algorithms optimization. That check is being made during the block stream job by the moment. Signed-off-by: Andrey Shinkevich --- block/copy-on-read.c | 13 +++++++++---- block/io.c | 3 ++- 2 files changed, 11 insertions(+), 5 deletions(-) diff --git a/block/copy-on-read.c b/block/copy-on-read.c index b136895..278a11a 100644 --- a/block/copy-on-read.c +++ b/block/copy-on-read.c @@ -148,10 +148,15 @@ static int coroutine_fn cor_co_preadv_part(BlockDrive= rState *bs, } } =20 - ret =3D bdrv_co_preadv_part(bs->file, offset, n, qiov, qiov_offset, - local_flags); - if (ret < 0) { - return ret; + if (!!(flags & BDRV_REQ_PREFETCH) & + !(local_flags & BDRV_REQ_COPY_ON_READ)) { + /* Skip non-guest reads if no copy needed */ + } else { + ret =3D bdrv_co_preadv_part(bs->file, offset, n, qiov, qiov_of= fset, + local_flags); + if (ret < 0) { + return ret; + } } =20 offset +=3D n; diff --git a/block/io.c b/block/io.c index 11df188..bff1808 100644 --- a/block/io.c +++ b/block/io.c @@ -1512,7 +1512,8 @@ static int coroutine_fn bdrv_aligned_preadv(BdrvChild= *child, =20 max_bytes =3D ROUND_UP(MAX(0, total_bytes - offset), align); if (bytes <=3D max_bytes && bytes <=3D max_transfer) { - ret =3D bdrv_driver_preadv(bs, offset, bytes, qiov, qiov_offset, 0= ); + ret =3D bdrv_driver_preadv(bs, offset, bytes, qiov, qiov_offset, + flags & bs->supported_read_flags); goto out; } =20 --=20 1.8.3.1