From nobody Thu Dec 18 04:15:50 2025 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 Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1752749856132827.8160681511364; Thu, 17 Jul 2025 03:57:36 -0700 (PDT) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ucMGQ-0007PC-Ok; Thu, 17 Jul 2025 06:54:58 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ucMGK-0007F4-Au; Thu, 17 Jul 2025 06:54:52 -0400 Received: from isrv.corpit.ru ([212.248.84.144]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ucMGH-00037s-1B; Thu, 17 Jul 2025 06:54:52 -0400 Received: from tsrv.corpit.ru (tsrv.tls.msk.ru [192.168.177.2]) by isrv.corpit.ru (Postfix) with ESMTP id D8B06137E1D; Thu, 17 Jul 2025 13:54:34 +0300 (MSK) Received: from think4mjt.origo (mjtthink.wg.tls.msk.ru [192.168.177.146]) by tsrv.corpit.ru (Postfix) with ESMTP id CAFAF249267; Thu, 17 Jul 2025 13:54:42 +0300 (MSK) From: Michael Tokarev To: qemu-devel@nongnu.org Cc: qemu-stable@nongnu.org, "Chaney, Ben" , Peter Xu , Michael Tokarev Subject: [Stable-7.2.19 17/26] migration: Don't sync volatile memory after migration completes Date: Thu, 17 Jul 2025 13:54:31 +0300 Message-ID: <20250717105442.735202-2-mjt@tls.msk.ru> X-Mailer: git-send-email 2.47.2 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable 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=212.248.84.144; envelope-from=mjt@tls.msk.ru; helo=isrv.corpit.ru X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, RCVD_IN_VALIDITY_SAFE_BLOCKED=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: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: qemu-devel-bounces+importer=patchew.org@nongnu.org X-ZM-MESSAGEID: 1752749857099116600 Content-Type: text/plain; charset="utf-8" From: "Chaney, Ben" Syncing volatile memory provides no benefit, instead it can cause performance issues in some cases. Only sync memory that is marked as non-volatile after migration completes on destination. Signed-off-by: Ben Chaney Fixes: bd108a44bc29 (migration: ram: Switch to ram block writeback) Link: https://lore.kernel.org/r/1CC43F59-336F-4A12-84AD-DB89E0A17A95@akamai= .com Signed-off-by: Peter Xu (cherry picked from commit 983899eab4939dc4dff67fa4d822c5b4df7eae21) Signed-off-by: Michael Tokarev diff --git a/migration/ram.c b/migration/ram.c index f25ebd9620..e3ab67acd4 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -3930,7 +3930,9 @@ static int ram_load_cleanup(void *opaque) RAMBlock *rb; =20 RAMBLOCK_FOREACH_NOT_IGNORED(rb) { - qemu_ram_block_writeback(rb); + if (memory_region_is_nonvolatile(rb->mr)) { + qemu_ram_block_writeback(rb); + } } =20 xbzrle_load_cleanup(); --=20 2.47.2