From patchwork Fri Feb 17 16:39:01 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peter Lieven X-Patchwork-Id: 729226 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3vPzKM4tcNz9s8B for ; Sat, 18 Feb 2017 03:40:21 +1100 (AEDT) Received: from localhost ([::1]:54642 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1celZy-0006y7-14 for incoming@patchwork.ozlabs.org; Fri, 17 Feb 2017 11:40:18 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:57418) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1celZ1-00063U-Js for qemu-devel@nongnu.org; Fri, 17 Feb 2017 11:39:20 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1celYy-0004Tr-GP for qemu-devel@nongnu.org; Fri, 17 Feb 2017 11:39:19 -0500 Received: from mx-v6.kamp.de ([2a02:248:0:51::16]:58550 helo=mx01.kamp.de) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1celYy-0004R8-6O for qemu-devel@nongnu.org; Fri, 17 Feb 2017 11:39:16 -0500 Received: (qmail 27250 invoked by uid 89); 17 Feb 2017 16:39:10 -0000 Received: from [195.62.97.28] by client-16-kamp (envelope-from , uid 89) with qmail-scanner-2010/03/19-MF (clamdscan: 0.99.2/23079. avast: 1.2.2/17010300. spamassassin: 3.4.1. Clear:RC:1(195.62.97.28):. Processed in 0.239449 secs); 17 Feb 2017 16:39:10 -0000 Received: from smtp.kamp.de (HELO submission.kamp.de) ([195.62.97.28]) by mx01.kamp.de with ESMTPS (DHE-RSA-AES256-GCM-SHA384 encrypted); 17 Feb 2017 16:39:08 -0000 X-GL_Whitelist: yes Received: (qmail 2995 invoked from network); 17 Feb 2017 16:39:07 -0000 Received: from lieven-pc.kamp-intra.net (HELO lieven-pc) (relay@kamp.de@::ffff:172.21.12.60) by submission.kamp.de with ESMTPS (DHE-RSA-AES256-GCM-SHA384 encrypted) ESMTPA; 17 Feb 2017 16:39:07 -0000 Received: by lieven-pc (Postfix, from userid 1000) id 3519720EA7; Fri, 17 Feb 2017 17:39:07 +0100 (CET) From: Peter Lieven To: qemu-devel@nongnu.org Date: Fri, 17 Feb 2017 17:39:01 +0100 Message-Id: <1487349541-10201-3-git-send-email-pl@kamp.de> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1487349541-10201-1-git-send-email-pl@kamp.de> References: <1487349541-10201-1-git-send-email-pl@kamp.de> X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 2a02:248:0:51::16 Subject: [Qemu-devel] [PATCH 2/2] block/nfs: try to avoid the bounce buffer in pwritev X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kwolf@redhat.com, jcody@redhat.com, Peter Lieven , qemu-block@nongnu.org, mreitz@redhat.com Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" if the passed qiov contains exactly one iov we can pass the buffer directly. Signed-off-by: Peter Lieven Reviewed-by: Jeff Cody --- block/nfs.c | 23 ++++++++++++++++------- 1 file changed, 16 insertions(+), 7 deletions(-) diff --git a/block/nfs.c b/block/nfs.c index ab5dcc2..bb4b75f 100644 --- a/block/nfs.c +++ b/block/nfs.c @@ -295,20 +295,27 @@ static int coroutine_fn nfs_co_pwritev(BlockDriverState *bs, uint64_t offset, NFSClient *client = bs->opaque; NFSRPC task; char *buf = NULL; + bool my_buffer = false; nfs_co_init_task(bs, &task); - buf = g_try_malloc(bytes); - if (bytes && buf == NULL) { - return -ENOMEM; + if (iov->niov != 1) { + buf = g_try_malloc(bytes); + if (bytes && buf == NULL) { + return -ENOMEM; + } + qemu_iovec_to_buf(iov, 0, buf, bytes); + my_buffer = true; + } else { + buf = iov->iov[0].iov_base; } - qemu_iovec_to_buf(iov, 0, buf, bytes); - if (nfs_pwrite_async(client->context, client->fh, offset, bytes, buf, nfs_co_generic_cb, &task) != 0) { - g_free(buf); + if (my_buffer) { + g_free(buf); + } return -ENOMEM; } @@ -317,7 +324,9 @@ static int coroutine_fn nfs_co_pwritev(BlockDriverState *bs, uint64_t offset, qemu_coroutine_yield(); } - g_free(buf); + if (my_buffer) { + g_free(buf); + } if (task.ret != bytes) { return task.ret < 0 ? task.ret : -EIO;