From nobody Sun Feb 8 21:05:49 2026 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org ARC-Seal: i=1; a=rsa-sha256; t=1614046905; cv=none; d=zohomail.com; s=zohoarc; b=XoCCXxamBdByzKDLGG06qUqplm+gXy/cXa4TAMQz3FWE7GGI/hEk+6TiBpasa/FxveNjwu2Wsr0BsW4o1ruGSeuZC7apeKFPU7yGhrW3zw8jxUtiPcIXtnINOgimSsCWROitBhzUaMS7p7pNZ4c9B8r+1e0X7pbuLnOvFfSYKmI= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1614046905; h=Content-Type:Content-Transfer-Encoding:Cc:Date:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:To; bh=+9ytmLtVD1igaT9L4XmOGm6vzCDYll6cHwUh2gJsEpo=; b=d/BFYCxsMuhXaU/RWjQASPfs61UNmr835nQ5Y7o4DPqSfzuga7fZhGBwTvyw0zRJ0pp6NRghX5/g7QBHAaZWXis9qCZSLEr5WLEaiLFLfPbs1QwR6aaOevzNtkfXUNr4aPIhJj0tPeUNIfBxqsPzO3hpRBaXvR2Qs/jj+MU0bsc= ARC-Authentication-Results: i=1; mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1614046905373491.07568682907186; Mon, 22 Feb 2021 18:21:45 -0800 (PST) Received: from localhost ([::1]:52406 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lENKa-0004pi-Cf for importer@patchew.org; Mon, 22 Feb 2021 21:21:44 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:51994) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lENGt-0001ul-Ob for qemu-devel@nongnu.org; Mon, 22 Feb 2021 21:17:55 -0500 Received: from szxga05-in.huawei.com ([45.249.212.191]:3484) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lENGs-0006Um-15 for qemu-devel@nongnu.org; Mon, 22 Feb 2021 21:17:55 -0500 Received: from DGGEMS410-HUB.china.huawei.com (unknown [172.30.72.59]) by szxga05-in.huawei.com (SkyGuard) with ESMTP id 4Dl2j20fP0zjRL8; Tue, 23 Feb 2021 10:16:06 +0800 (CST) Received: from DESKTOP-6NKE0BC.china.huawei.com (10.174.185.210) by DGGEMS410-HUB.china.huawei.com (10.3.19.210) with Microsoft SMTP Server id 14.3.498.0; Tue, 23 Feb 2021 10:17:29 +0800 From: Kunkun Jiang To: Juan Quintela , "Dr . David Alan Gilbert" , "open list:All patches CC here" Subject: [PATCH 1/3] migration/ram: Modify the code comment of ram_save_host_page() Date: Tue, 23 Feb 2021 10:16:43 +0800 Message-ID: <20210223021646.500-2-jiangkunkun@huawei.com> X-Mailer: git-send-email 2.26.2.windows.1 In-Reply-To: <20210223021646.500-1-jiangkunkun@huawei.com> References: <20210223021646.500-1-jiangkunkun@huawei.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Originating-IP: [10.174.185.210] X-CFilter-Loop: Reflected Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=45.249.212.191; envelope-from=jiangkunkun@huawei.com; helo=szxga05-in.huawei.com X-Spam_score_int: -41 X-Spam_score: -4.2 X-Spam_bar: ---- X-Spam_report: (-4.2 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_MED=-2.3, RCVD_IN_MSPIKE_H2=-0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Zenghui Yu , wanghaibin.wang@huawei.com, Keqian Zhu Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" Content-Type: text/plain; charset="utf-8" The ram_save_host_page() has been modified several times since its birth. But the comment hasn't been modified as it should be. It'd better to modify the comment to explain ram_save_host_page() more clearly. Signed-off-by: Keqian Zhu Signed-off-by: Kunkun Jiang --- migration/ram.c | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-) diff --git a/migration/ram.c b/migration/ram.c index 72143da0ac..fc49c3f898 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -1970,15 +1970,16 @@ static int ram_save_target_page(RAMState *rs, PageS= earchStatus *pss, } =20 /** - * ram_save_host_page: save a whole host page + * ram_save_host_page: save a whole host page or the rest of a block * - * Starting at *offset send pages up to the end of the current host - * page. It's valid for the initial offset to point into the middle of - * a host page in which case the remainder of the hostpage is sent. - * Only dirty target pages are sent. Note that the host page size may - * be a huge page for this block. - * The saving stops at the boundary of the used_length of the block - * if the RAMBlock isn't a multiple of the host page size. + * Starting at pss->page send pages up to the end of the current host + * page or the boundary of used_length of the block (if the RAMBlock + * isn't a multiple of the host page size). The min one is selected. + * Only dirty target pages are sent. + * + * Note that the host page size may be a huge page for this block, it's + * valid for the initial offset to point into the middle of a host page + * in which case the remainder of the hostpage is sent. * * Returns the number of pages written or negative on error * --=20 2.23.0 From nobody Sun Feb 8 21:05:49 2026 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org ARC-Seal: i=1; a=rsa-sha256; t=1614046899; cv=none; d=zohomail.com; s=zohoarc; b=k8fE4tbSEgX4fk0ipP1xkUCpN7L8cZSB4u9KP77pxkyVpVxMkWD2rz9ZHUY4IrterFjDey/9nEe1F96Yca+zmIJ5wui4JmEr2Yjjzdl+66Lj9VLRCqxQXQAsNOICFfPJzHPUiV5Qj5qGbBjyc/wLiKDLmeCJDhZ/6xca0FK6aPM= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1614046899; h=Content-Type:Content-Transfer-Encoding:Cc:Date:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:To; bh=53Xz4EOhqFo9oGjHZH9otrn5w2ubqGPMog07XM6ZcMA=; b=mO7rBUda9G2HytOc6zDDUOehrXKtcRo9VOyG/v2ZB1g/A8dzGeSObAPHicp7dpijj9LjBAziVw6HCuvvY2nlv761+mqWp4QdRZJUm1jWWBzRaS4Q1BQK/X2tMkUF7w5t3OHCtcTExJGTpWehp0Z3KyHCZLXuai5GRC9c/zsmObs= ARC-Authentication-Results: i=1; mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1614046899261696.2511550806275; Mon, 22 Feb 2021 18:21:39 -0800 (PST) Received: from localhost ([::1]:52248 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lENKU-0004gI-7W for importer@patchew.org; Mon, 22 Feb 2021 21:21:38 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:51982) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lENGr-0001r4-QR for qemu-devel@nongnu.org; Mon, 22 Feb 2021 21:17:53 -0500 Received: from szxga07-in.huawei.com ([45.249.212.35]:2653) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lENGo-0006Wu-SN for qemu-devel@nongnu.org; Mon, 22 Feb 2021 21:17:53 -0500 Received: from DGGEMS410-HUB.china.huawei.com (unknown [172.30.72.59]) by szxga07-in.huawei.com (SkyGuard) with ESMTP id 4Dl2j735qTz7pKx; Tue, 23 Feb 2021 10:16:11 +0800 (CST) Received: from DESKTOP-6NKE0BC.china.huawei.com (10.174.185.210) by DGGEMS410-HUB.china.huawei.com (10.3.19.210) with Microsoft SMTP Server id 14.3.498.0; Tue, 23 Feb 2021 10:17:34 +0800 From: Kunkun Jiang To: Juan Quintela , "Dr . David Alan Gilbert" , "open list:All patches CC here" Subject: [PATCH 2/3] migration/ram: Modify ram_save_host_page() to match the comment Date: Tue, 23 Feb 2021 10:16:44 +0800 Message-ID: <20210223021646.500-3-jiangkunkun@huawei.com> X-Mailer: git-send-email 2.26.2.windows.1 In-Reply-To: <20210223021646.500-1-jiangkunkun@huawei.com> References: <20210223021646.500-1-jiangkunkun@huawei.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Originating-IP: [10.174.185.210] X-CFilter-Loop: Reflected Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=45.249.212.35; envelope-from=jiangkunkun@huawei.com; helo=szxga07-in.huawei.com X-Spam_score_int: -41 X-Spam_score: -4.2 X-Spam_bar: ---- X-Spam_report: (-4.2 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_MED=-2.3, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Zenghui Yu , wanghaibin.wang@huawei.com, Keqian Zhu Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" Content-Type: text/plain; charset="utf-8" According to the comment, when the host page is a huge page, the migration_rate_limit() should be executed. If not, this function can be omitted to save time. Signed-off-by: Keqian Zhu Signed-off-by: Kunkun Jiang --- migration/ram.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/migration/ram.c b/migration/ram.c index fc49c3f898..c7e18dc2fc 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -2017,7 +2017,9 @@ static int ram_save_host_page(RAMState *rs, PageSearc= hStatus *pss, pages +=3D tmppages; pss->page++; /* Allow rate limiting to happen in the middle of huge pages */ - migration_rate_limit(); + if (pagesize_bits > 1) { + migration_rate_limit(); + } } while ((pss->page & (pagesize_bits - 1)) && offset_in_ramblock(pss->block, ((ram_addr_t)pss->page) << TARGET_PAGE_BIT= S)); --=20 2.23.0 From nobody Sun Feb 8 21:05:49 2026 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org ARC-Seal: i=1; a=rsa-sha256; t=1614046738; cv=none; d=zohomail.com; s=zohoarc; b=nVCPgzzSNAelj64ZDZMprRvn2pnfHHGKLKC984xBTEf+7KQ+MV5rzy7c5toP0fZm0Cn18Mpl5ZnUMDylo5T2VXTRngcftxnxOJCfx5/t7XintUjDTGlQuXThOa2dfMJh32GzIOEPYHSusMMTOND6xq+ixqFmctl0mUJ52LzNY+0= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1614046738; h=Content-Type:Content-Transfer-Encoding:Cc:Date:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:To; bh=2vMxTT0iGVJE4fbPxI3sSJwQSS0bHmE0O23XI9G7i3Y=; b=Rc3GS0NF659R9K1zkXe6aTPpzeYiPOnrAjpAPy+XAxBxlzjptV5Qt1LZJurMZkxNJOUJVrhN1V+cN1dI7dGYBOMJH7yR0ZVFVL4wGuGFYqXxNOaKT5CRp7MhdpKlmp1GCLaWcad9Bt82+esR2AChonxP7GrzQvgl8ipXpfAN+s0= ARC-Authentication-Results: i=1; mx.zohomail.com; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1614046738545264.18776855991405; Mon, 22 Feb 2021 18:18:58 -0800 (PST) Received: from localhost ([::1]:48024 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lENHt-0002jm-Bp for importer@patchew.org; Mon, 22 Feb 2021 21:18:57 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:51980) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lENGq-0001pq-OP for qemu-devel@nongnu.org; Mon, 22 Feb 2021 21:17:52 -0500 Received: from szxga07-in.huawei.com ([45.249.212.35]:2652) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lENGo-0006Wv-JO for qemu-devel@nongnu.org; Mon, 22 Feb 2021 21:17:52 -0500 Received: from DGGEMS410-HUB.china.huawei.com (unknown [172.30.72.59]) by szxga07-in.huawei.com (SkyGuard) with ESMTP id 4Dl2j72t3qz7nm3; Tue, 23 Feb 2021 10:16:11 +0800 (CST) Received: from DESKTOP-6NKE0BC.china.huawei.com (10.174.185.210) by DGGEMS410-HUB.china.huawei.com (10.3.19.210) with Microsoft SMTP Server id 14.3.498.0; Tue, 23 Feb 2021 10:17:39 +0800 From: Kunkun Jiang To: Juan Quintela , "Dr . David Alan Gilbert" , "open list:All patches CC here" Subject: [PATCH 3/3] migration/ram: Optimize ram_save_host_page() Date: Tue, 23 Feb 2021 10:16:45 +0800 Message-ID: <20210223021646.500-4-jiangkunkun@huawei.com> X-Mailer: git-send-email 2.26.2.windows.1 In-Reply-To: <20210223021646.500-1-jiangkunkun@huawei.com> References: <20210223021646.500-1-jiangkunkun@huawei.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Originating-IP: [10.174.185.210] X-CFilter-Loop: Reflected Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=45.249.212.35; envelope-from=jiangkunkun@huawei.com; helo=szxga07-in.huawei.com X-Spam_score_int: -41 X-Spam_score: -4.2 X-Spam_bar: ---- X-Spam_report: (-4.2 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_DNSWL_MED=-2.3, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Zenghui Yu , wanghaibin.wang@huawei.com, Keqian Zhu Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" Content-Type: text/plain; charset="utf-8" Starting from pss->page, ram_save_host_page() will check every page and send the dirty pages up to the end of the current host page or the boundary of used_length of the block. If the host page size is a huge page, the step "check" will take a lot of time. This will improve performance to use migration_bitmap_find_dirty(). Signed-off-by: Keqian Zhu Signed-off-by: Kunkun Jiang --- migration/ram.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/migration/ram.c b/migration/ram.c index c7e18dc2fc..c7a2350198 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -1994,6 +1994,8 @@ static int ram_save_host_page(RAMState *rs, PageSearc= hStatus *pss, int tmppages, pages =3D 0; size_t pagesize_bits =3D qemu_ram_pagesize(pss->block) >> TARGET_PAGE_BITS; + unsigned long hostpage_boundary =3D + QEMU_ALIGN_UP(pss->page + 1, pagesize_bits); unsigned long start_page =3D pss->page; int res; =20 @@ -2005,8 +2007,7 @@ static int ram_save_host_page(RAMState *rs, PageSearc= hStatus *pss, do { /* Check the pages is dirty and if it is send it */ if (!migration_bitmap_clear_dirty(rs, pss->block, pss->page)) { - pss->page++; - continue; + goto find_next; } =20 tmppages =3D ram_save_target_page(rs, pss, last_stage); @@ -2015,16 +2016,17 @@ static int ram_save_host_page(RAMState *rs, PageSea= rchStatus *pss, } =20 pages +=3D tmppages; - pss->page++; /* Allow rate limiting to happen in the middle of huge pages */ if (pagesize_bits > 1) { migration_rate_limit(); } - } while ((pss->page & (pagesize_bits - 1)) && +find_next: + pss->page =3D migration_bitmap_find_dirty(rs, pss->block, pss->pag= e); + } while ((pss->page < hostpage_boundary) && offset_in_ramblock(pss->block, ((ram_addr_t)pss->page) << TARGET_PAGE_BIT= S)); - /* The offset we leave with is the last one we looked at */ - pss->page--; + /* The offset we leave with is the min boundary of host page and block= */ + pss->page =3D MIN(pss->page, hostpage_boundary) - 1; =20 res =3D ram_save_release_protection(rs, pss, start_page); return (res < 0 ? res : pages); --=20 2.23.0