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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+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP 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;