From patchwork Fri Feb 24 17:46:59 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeff Cody X-Patchwork-Id: 9590925 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 8C0C4601AE for ; Fri, 24 Feb 2017 18:23:26 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 80D51287AC for ; Fri, 24 Feb 2017 18:23:26 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 75D85288DC; Fri, 24 Feb 2017 18:23:26 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id B692C287AC for ; Fri, 24 Feb 2017 18:23:25 +0000 (UTC) Received: from localhost ([::1]:39163 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1chKWa-0002za-NS for patchwork-qemu-devel@patchwork.kernel.org; Fri, 24 Feb 2017 13:23:24 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:37863) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1chJxV-0006Hp-Sh for qemu-devel@nongnu.org; Fri, 24 Feb 2017 12:47:10 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1chJxU-0004uP-Ty for qemu-devel@nongnu.org; Fri, 24 Feb 2017 12:47:09 -0500 Received: from mx1.redhat.com ([209.132.183.28]:38624) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1chJxS-0004sY-NJ; Fri, 24 Feb 2017 12:47:06 -0500 Received: from int-mx14.intmail.prod.int.phx2.redhat.com (int-mx14.intmail.prod.int.phx2.redhat.com [10.5.11.27]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 7A6393A7698; Fri, 24 Feb 2017 17:47:05 +0000 (UTC) Received: from localhost (ovpn-116-95.phx2.redhat.com [10.3.116.95]) by int-mx14.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id v1OHl4IR001040 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Fri, 24 Feb 2017 12:47:05 -0500 From: Jeff Cody To: qemu-block@nongnu.org Date: Fri, 24 Feb 2017 12:46:59 -0500 Message-Id: <20170224174700.30816-3-jcody@redhat.com> In-Reply-To: <20170224174700.30816-1-jcody@redhat.com> References: <20170224174700.30816-1-jcody@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.27 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.29]); Fri, 24 Feb 2017 17:47:05 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PULL 2/3] 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: peter.maydell@linaro.org, jcody@redhat.com, qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP From: Peter Lieven if the passed qiov contains exactly one iov we can pass the buffer directly. Signed-off-by: Peter Lieven Reviewed-by: Jeff Cody Message-id: 1487349541-10201-3-git-send-email-pl@kamp.de Signed-off-by: Jeff Cody --- block/nfs.c | 35 ++++++++++++++++++++++------------- 1 file changed, 22 insertions(+), 13 deletions(-) diff --git a/block/nfs.c b/block/nfs.c index c11c4c9..ffb54be 100644 --- a/block/nfs.c +++ b/block/nfs.c @@ -302,30 +302,39 @@ 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) { + if (my_buffer) { + g_free(buf); + } + return -ENOMEM; + } + + nfs_set_events(client); + while (!task.complete) { + qemu_coroutine_yield(); + } + + if (my_buffer) { g_free(buf); - return -ENOMEM; } - nfs_set_events(client); - while (!task.complete) { - qemu_coroutine_yield(); - } - - g_free(buf); - if (task.ret != bytes) { return task.ret < 0 ? task.ret : -EIO; }