From patchwork Wed Jan 4 06:58:11 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dou Liyang X-Patchwork-Id: 710835 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)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 3tthZm2KFrz9t1C for ; Wed, 4 Jan 2017 18:02:24 +1100 (AEDT) Received: from localhost ([::1]:37643 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cOfaY-0003iW-6l for incoming@patchwork.ozlabs.org; Wed, 04 Jan 2017 02:02:22 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:55954) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cOfX7-0001DO-Mw for qemu-devel@nongnu.org; Wed, 04 Jan 2017 01:58:50 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cOfX3-0005qu-Ua for qemu-devel@nongnu.org; Wed, 04 Jan 2017 01:58:49 -0500 Received: from [59.151.112.132] (port=39311 helo=heian.cn.fujitsu.com) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cOfX3-0005qA-1k for qemu-devel@nongnu.org; Wed, 04 Jan 2017 01:58:45 -0500 X-IronPort-AV: E=Sophos;i="5.22,518,1449504000"; d="scan'208";a="14459271" Received: from unknown (HELO cn.fujitsu.com) ([10.167.33.5]) by heian.cn.fujitsu.com with ESMTP; 04 Jan 2017 14:58:28 +0800 Received: from G08CNEXCHPEKD02.g08.fujitsu.local (unknown [10.167.33.83]) by cn.fujitsu.com (Postfix) with ESMTP id 08D1946701B9; Wed, 4 Jan 2017 14:58:26 +0800 (CST) Received: from localhost.localdomain.localdomain (10.167.226.106) by G08CNEXCHPEKD02.g08.fujitsu.local (10.167.33.89) with Microsoft SMTP Server (TLS) id 14.3.319.2; Wed, 4 Jan 2017 14:58:32 +0800 From: Dou Liyang To: , , , , , , Date: Wed, 4 Jan 2017 14:58:11 +0800 Message-ID: <1483513091-30661-3-git-send-email-douly.fnst@cn.fujitsu.com> X-Mailer: git-send-email 2.5.5 In-Reply-To: <1483513091-30661-1-git-send-email-douly.fnst@cn.fujitsu.com> References: <1483513091-30661-1-git-send-email-douly.fnst@cn.fujitsu.com> MIME-Version: 1.0 X-Originating-IP: [10.167.226.106] X-yoursite-MailScanner-ID: 08D1946701B9.ADF0E X-yoursite-MailScanner: Found to be clean X-yoursite-MailScanner-From: douly.fnst@cn.fujitsu.com X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 59.151.112.132 Subject: [Qemu-devel] [PATCH RFC v3 2/2] block/qapi: reduce the execution time of qmp_query_blockstats 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: izumi.taku@jp.fujitsu.com, caoj.fnst@cn.fujitsu.com, fanc.fnst@cn.fujitsu.com, qemu-devel@nongnu.org, Dou Liyang Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" In order to reduce the execution time, this patch optimize the qmp_query_blockstats(): Remove the next_query_bds function. Remove the bdrv_query_stats function. Remove some judgement sentence. The original qmp_query_blockstats calls next_query_bds to get the next objects in each loops. In the next_query_bds, it checks the query_nodes and blk. It also call bdrv_query_stats to get the stats, In the bdrv_query_stats, it checks blk and bs each times. This waste more times, which may stall the main loop a bit. And if the disk is too many and donot use the dataplane feature, this may affect the performance in main loop thread. This patch removes that two functions, and makes the structure clearly. Signed-off-by: Dou Liyang --- block/qapi.c | 72 +++++++++++++++++++++++------------------------------------- 1 file changed, 28 insertions(+), 44 deletions(-) diff --git a/block/qapi.c b/block/qapi.c index bc622cd..6e1e8bd 100644 --- a/block/qapi.c +++ b/block/qapi.c @@ -456,23 +456,6 @@ static BlockStats *bdrv_query_bds_stats(const BlockDriverState *bs, return s; } -static BlockStats *bdrv_query_stats(BlockBackend *blk, - const BlockDriverState *bs, - bool query_backing) -{ - BlockStats *s; - - s = bdrv_query_bds_stats(bs, query_backing); - - if (blk) { - s->has_device = true; - s->device = g_strdup(blk_name(blk)); - bdrv_query_blk_stats(s->stats, blk); - } - - return s; -} - BlockInfoList *qmp_query_block(Error **errp) { BlockInfoList *head = NULL, **p_next = &head; @@ -496,42 +479,43 @@ BlockInfoList *qmp_query_block(Error **errp) return head; } -static bool next_query_bds(BlockBackend **blk, BlockDriverState **bs, - bool query_nodes) -{ - if (query_nodes) { - *bs = bdrv_next_node(*bs); - return !!*bs; - } - - *blk = blk_next(*blk); - *bs = *blk ? blk_bs(*blk) : NULL; - - return !!*blk; -} - BlockStatsList *qmp_query_blockstats(bool has_query_nodes, bool query_nodes, Error **errp) { BlockStatsList *head = NULL, **p_next = &head; - BlockBackend *blk = NULL; - BlockDriverState *bs = NULL; + BlockBackend *blk; + BlockDriverState *bs; /* Just to be safe if query_nodes is not always initialized */ - query_nodes = has_query_nodes && query_nodes; - - while (next_query_bds(&blk, &bs, query_nodes)) { - BlockStatsList *info = g_malloc0(sizeof(*info)); - AioContext *ctx = blk ? blk_get_aio_context(blk) - : bdrv_get_aio_context(bs); + if (has_query_nodes && query_nodes) { + for (bs = bdrv_next_node(NULL); bs; bs = bdrv_next_node(bs)) { + BlockStatsList *info = g_malloc0(sizeof(*info)); + AioContext *ctx = bdrv_get_aio_context(bs); - aio_context_acquire(ctx); - info->value = bdrv_query_stats(blk, bs, !query_nodes); - aio_context_release(ctx); + aio_context_acquire(ctx); + info->value = bdrv_query_bds_stats(bs, false); + aio_context_release(ctx); - *p_next = info; - p_next = &info->next; + *p_next = info; + p_next = &info->next; + } + } else { + for (blk = blk_next(NULL); blk; blk = blk_next(blk)) { + BlockStatsList *info = g_malloc0(sizeof(*info)); + AioContext *ctx = blk_get_aio_context(blk); + + aio_context_acquire(ctx); + BlockStats *s = bdrv_query_bds_stats(blk_bs(blk), true); + s->has_device = true; + s->device = g_strdup(blk_name(blk)); + bdrv_query_blk_stats(s->stats, blk); + aio_context_release(ctx); + + info->value = s; + *p_next = info; + p_next = &info->next; + } } return head;