From patchwork Fri Mar 22 14:48:00 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Orit Wasserman X-Patchwork-Id: 230074 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 40D602C00A5 for ; Sat, 23 Mar 2013 01:47:59 +1100 (EST) Received: from localhost ([::1]:51664 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UJ3G9-0006hu-Gx for incoming@patchwork.ozlabs.org; Fri, 22 Mar 2013 10:47:57 -0400 Received: from eggs.gnu.org ([208.118.235.92]:43098) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UJ3FV-0006JW-Kw for qemu-devel@nongnu.org; Fri, 22 Mar 2013 10:47:19 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1UJ3FP-0007ik-Dl for qemu-devel@nongnu.org; Fri, 22 Mar 2013 10:47:17 -0400 Received: from mx1.redhat.com ([209.132.183.28]:54244) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UJ3FP-0007iP-3q for qemu-devel@nongnu.org; Fri, 22 Mar 2013 10:47:11 -0400 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id r2MEl93K014239 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Fri, 22 Mar 2013 10:47:09 -0400 Received: from dhcp-1-120.tlv.redhat.com (vpn-200-53.tlv.redhat.com [10.35.200.53]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id r2MEkukn010401; Fri, 22 Mar 2013 10:47:07 -0400 From: Orit Wasserman To: qemu-devel@nongnu.org Date: Fri, 22 Mar 2013 16:48:00 +0200 Message-Id: <1363963683-26157-5-git-send-email-owasserm@redhat.com> In-Reply-To: <1363963683-26157-1-git-send-email-owasserm@redhat.com> References: <1363963683-26157-1-git-send-email-owasserm@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.22 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 209.132.183.28 Cc: mst@redhat.com, quintela@redhat.com, Orit Wasserman , pbonzini@redhat.com, chegu_vinod@hp.com Subject: [Qemu-devel] [PATCH v5 4/7] Store the data to send also in iovec X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org All data is still copied into the static buffer. Adjacent iovecs are coalesced so we send one big buffer instead of many small buffers. Signed-off-by: Orit Wasserman --- savevm.c | 24 ++++++++++++++++++++++-- 1 file changed, 22 insertions(+), 2 deletions(-) diff --git a/savevm.c b/savevm.c index 2ba0d85..8dad9ef 100644 --- a/savevm.c +++ b/savevm.c @@ -114,6 +114,7 @@ void qemu_announce_self(void) /* savevm/loadvm support */ #define IO_BUF_SIZE 32768 +#define MAX_IOV_SIZE MIN(IOV_MAX, 64) struct QEMUFile { const QEMUFileOps *ops; @@ -129,6 +130,9 @@ struct QEMUFile { int buf_size; /* 0 when writing */ uint8_t buf[IO_BUF_SIZE]; + struct iovec iov[MAX_IOV_SIZE]; + unsigned int iovcnt; + int last_error; }; @@ -528,6 +532,7 @@ static void qemu_fflush(QEMUFile *f) f->pos += f->buf_index; } f->buf_index = 0; + f->iovcnt = 0; } if (ret < 0) { qemu_file_set_error(f, ret); @@ -601,6 +606,18 @@ int qemu_fclose(QEMUFile *f) return ret; } +static void add_to_iovec(QEMUFile *f, const uint8_t *buf, int size) +{ + /* check for adjacent buffer and coalesce them */ + if (f->iovcnt > 0 && buf == f->iov[f->iovcnt - 1].iov_base + + f->iov[f->iovcnt - 1].iov_len) { + f->iov[f->iovcnt - 1].iov_len += size; + } else { + f->iov[f->iovcnt].iov_base = (uint8_t *)buf; + f->iov[f->iovcnt++].iov_len = size; + } +} + void qemu_put_buffer(QEMUFile *f, const uint8_t *buf, int size) { int l; @@ -620,12 +637,13 @@ void qemu_put_buffer(QEMUFile *f, const uint8_t *buf, int size) if (l > size) l = size; memcpy(f->buf + f->buf_index, buf, l); + add_to_iovec(f, f->buf + f->buf_index, l); f->is_write = 1; f->buf_index += l; f->bytes_xfer += l; buf += l; size -= l; - if (f->buf_index >= IO_BUF_SIZE) { + if (f->buf_index >= IO_BUF_SIZE || f->iovcnt >= MAX_IOV_SIZE) { qemu_fflush(f); if (qemu_file_get_error(f)) { break; @@ -650,7 +668,9 @@ void qemu_put_byte(QEMUFile *f, int v) f->is_write = 1; f->bytes_xfer++; - if (f->buf_index >= IO_BUF_SIZE) { + add_to_iovec(f, f->buf + (f->buf_index - 1), 1); + + if (f->buf_index >= IO_BUF_SIZE || f->iovcnt >= MAX_IOV_SIZE) { qemu_fflush(f); } }