From nobody Sun Feb 8 19:38:00 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; dmarc=fail(p=none dis=none) header.from=intel.com ARC-Seal: i=1; a=rsa-sha256; t=1610506896; cv=none; d=zohomail.com; s=zohoarc; b=Vivhycvtau9StsOFKTYMHn/83SlB81nVFPqhrrpAV0LEQtP+Yb4FlL6yt+RVXOMcg76QlY2Fh0IYzFYpMkMD+L+ly0GGhXaAmi9RlfsA4i776kwtIcvjFq56zYLG2F+e2UtSFUZZi4LXgNm+6NRsVfA5W2uxezT1jD7QUtJZz58= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1610506896; h=Cc:Date:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:Message-ID:References:Sender:Subject:To; bh=gPldfBZjwUMVgX2VL1UbyX0Kyt5poFvE7sPOsy9anco=; b=i9Sw8ZRl8olNHGKAhv8oMYJ8K07FSlCf8yXdC42FhpDe7Ew7u3sK0gVt5LUiLP6g7Xgu1PLBs4KLrTImZ4YXoSrCm9rttAAc3moUDw69zRdyfR8TKjuzFdP1ICZqcDgH02Y31FUFoRaQBnfzk+zuiVmZd0eFQuZCzmGJ5RfXxWw= 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; dmarc=fail header.from= (p=none dis=none) header.from= Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1610506896640757.8146108612427; Tue, 12 Jan 2021 19:01:36 -0800 (PST) Received: from localhost ([::1]:59932 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kzWPf-0005BG-Dk for importer@patchew.org; Tue, 12 Jan 2021 22:01:35 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:56750) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kzWI8-0005y9-7G for qemu-devel@nongnu.org; Tue, 12 Jan 2021 21:53:50 -0500 Received: from mga09.intel.com ([134.134.136.24]:58713) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kzWI4-00043O-Az for qemu-devel@nongnu.org; Tue, 12 Jan 2021 21:53:47 -0500 Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Jan 2021 18:53:43 -0800 Received: from unknown (HELO localhost.localdomain.bj.intel.com) ([10.240.192.103]) by fmsmga001.fm.intel.com with ESMTP; 12 Jan 2021 18:53:41 -0800 IronPort-SDR: cFYMQYq7PArGTvU+oNw0yF1jaLs2VSHW9btbPe5Xv4cMFcqczX5fi3jy9V5SLq4Bdq7kTf4olD SPAvmziY7n8A== X-IronPort-AV: E=McAfee;i="6000,8403,9862"; a="178289696" X-IronPort-AV: E=Sophos;i="5.79,343,1602572400"; d="scan'208";a="178289696" IronPort-SDR: ia2HoH++/SgJ1hqdoHlvCX3K1n5M1XbhdaQ1q6whi3GdYW8nuYMOVZkguhwEaTIJNcdpfEdQh+ ZDqv9RqZOb4Q== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.79,343,1602572400"; d="scan'208";a="464750355" From: leirao To: chen.zhang@intel.com, lizhijian@cn.fujitsu.com, jasowang@redhat.com, zhang.zhanghailiang@huawei.com, quintela@redhat.com, dgilbert@redhat.com Subject: [PATCH 08/10] Reduce the PVM stop time during Checkpoint Date: Wed, 13 Jan 2021 10:46:33 +0800 Message-Id: <1610505995-144129-9-git-send-email-lei.rao@intel.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1610505995-144129-1-git-send-email-lei.rao@intel.com> References: <1610505995-144129-1-git-send-email-lei.rao@intel.com> 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=134.134.136.24; envelope-from=lei.rao@intel.com; helo=mga09.intel.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_H3=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: "Rao, Lei" , qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" From: "Rao, Lei" When flushing memory from ram cache to ram during every checkpoint on secondary VM, we can copy continuous chunks of memory instead of 4096 bytes per time to reduce the time of VM stop during checkpoint. Signed-off-by: Lei Rao --- migration/ram.c | 44 +++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 41 insertions(+), 3 deletions(-) diff --git a/migration/ram.c b/migration/ram.c index 7811cde..d875e9a 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -806,6 +806,39 @@ unsigned long migration_bitmap_find_dirty(RAMState *rs= , RAMBlock *rb, return next; } =20 +/* + * colo_bitmap_find_diry:find contiguous dirty pages from start + * + * Returns the page offset within memory region of the start of the contig= uout + * dirty page + * + * @rs: current RAM state + * @rb: RAMBlock where to search for dirty pages + * @start: page where we start the search + * @num: the number of contiguous dirty pages + */ +static inline +unsigned long colo_bitmap_find_dirty(RAMState *rs, RAMBlock *rb, + unsigned long start, unsigned long *n= um) +{ + unsigned long size =3D rb->used_length >> TARGET_PAGE_BITS; + unsigned long *bitmap =3D rb->bmap; + unsigned long first, next; + + if (ramblock_is_ignored(rb)) { + return size; + } + + first =3D find_next_bit(bitmap, size, start); + if (first >=3D size) { + return first; + } + next =3D find_next_zero_bit(bitmap, size, first + 1); + assert(next >=3D first); + *num =3D next - first; + return first; +} + static inline bool migration_bitmap_clear_dirty(RAMState *rs, RAMBlock *rb, unsigned long page) @@ -3372,6 +3405,8 @@ void colo_flush_ram_cache(void) void *dst_host; void *src_host; unsigned long offset =3D 0; + unsigned long num =3D 0; + unsigned long i =3D 0; =20 memory_global_dirty_log_sync(); WITH_RCU_READ_LOCK_GUARD() { @@ -3385,19 +3420,22 @@ void colo_flush_ram_cache(void) block =3D QLIST_FIRST_RCU(&ram_list.blocks); =20 while (block) { - offset =3D migration_bitmap_find_dirty(ram_state, block, offse= t); + offset =3D colo_bitmap_find_dirty(ram_state, block, offset, &n= um); =20 if (((ram_addr_t)offset) << TARGET_PAGE_BITS >=3D block->used_length) { offset =3D 0; + num =3D 0; block =3D QLIST_NEXT_RCU(block, next); } else { - migration_bitmap_clear_dirty(ram_state, block, offset); + for (i =3D 0; i < num; i++) { + migration_bitmap_clear_dirty(ram_state, block, offset = + i); + } dst_host =3D block->host + (((ram_addr_t)offset) << TARGET_PAGE_BITS); src_host =3D block->colo_cache + (((ram_addr_t)offset) << TARGET_PAGE_BITS); - memcpy(dst_host, src_host, TARGET_PAGE_SIZE); + memcpy(dst_host, src_host, TARGET_PAGE_SIZE * num); } } } --=20 1.8.3.1