From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 1230ED3C52C for ; Thu, 17 Oct 2024 18:58:27 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1t1Vh0-0008Rv-Va; Thu, 17 Oct 2024 14:57:51 -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 1t1Vgy-0008RW-PL for qemu-devel@nongnu.org; Thu, 17 Oct 2024 14:57:48 -0400 Received: from smtp-out2.suse.de ([2a07:de40:b251:101:10:150:64:2]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1t1Vgx-0004RZ-67 for qemu-devel@nongnu.org; Thu, 17 Oct 2024 14:57:48 -0400 Received: from imap1.dmz-prg2.suse.org (imap1.dmz-prg2.suse.org [IPv6:2a07:de40:b281:104:10:150:64:97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id 549CE1FD49; Thu, 17 Oct 2024 18:57:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1729191465; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=QUdv7OgMyYMdQfNuORRlZ8D8ygnBCKHyV1/G0yrz5ew=; b=06d9FwpHR1fekDJ5tvsNyGP1lyVRqIuLGEfeE6jlRriRcQEEQsgnXtM08cdcbTtnYUc/jg dmdD59cNGI0AjQ1OiYPGsM9jz+WMck1NwG+gqW7K49BHgUT7LcIL/rE28EwCXNB9Is5C3G 0eYPr55Oq2yzUcD+eC0rTay2fvecf9Q= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1729191465; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=QUdv7OgMyYMdQfNuORRlZ8D8ygnBCKHyV1/G0yrz5ew=; b=S6rCQpinA043DXwxr2SxjzR8a7cZ2maoUzzuWfxN8GT2/z6ORC1iu/0/xLDmqpPGUZtGyw fhuv5N8G8ykRqHAA== Authentication-Results: smtp-out2.suse.de; dkim=pass header.d=suse.de header.s=susede2_rsa header.b=06d9FwpH; dkim=pass header.d=suse.de header.s=susede2_ed25519 header.b=S6rCQpin DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1729191465; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=QUdv7OgMyYMdQfNuORRlZ8D8ygnBCKHyV1/G0yrz5ew=; b=06d9FwpHR1fekDJ5tvsNyGP1lyVRqIuLGEfeE6jlRriRcQEEQsgnXtM08cdcbTtnYUc/jg dmdD59cNGI0AjQ1OiYPGsM9jz+WMck1NwG+gqW7K49BHgUT7LcIL/rE28EwCXNB9Is5C3G 0eYPr55Oq2yzUcD+eC0rTay2fvecf9Q= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1729191465; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=QUdv7OgMyYMdQfNuORRlZ8D8ygnBCKHyV1/G0yrz5ew=; b=S6rCQpinA043DXwxr2SxjzR8a7cZ2maoUzzuWfxN8GT2/z6ORC1iu/0/xLDmqpPGUZtGyw fhuv5N8G8ykRqHAA== Received: from imap1.dmz-prg2.suse.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by imap1.dmz-prg2.suse.org (Postfix) with ESMTPS id D280413A42; Thu, 17 Oct 2024 18:57:44 +0000 (UTC) Received: from dovecot-director2.suse.de ([2a07:de40:b281:106:10:150:64:167]) by imap1.dmz-prg2.suse.org with ESMTPSA id 2w8PJiheEWcZcgAAD6G6ig (envelope-from ); Thu, 17 Oct 2024 18:57:44 +0000 From: Fabiano Rosas To: yong.huang@smartx.com, qemu-devel@nongnu.org Cc: Peter Xu , Richard Henderson , Paolo Bonzini , yong.huang@smartx.com Subject: Re: [PATCH v4 5/6] migration: Support periodic RAMBlock dirty bitmap sync In-Reply-To: References: Date: Thu, 17 Oct 2024 15:57:42 -0300 Message-ID: <87frou36c9.fsf@suse.de> MIME-Version: 1.0 Content-Type: text/plain X-Rspamd-Queue-Id: 549CE1FD49 X-Spamd-Result: default: False [-4.31 / 50.00]; BAYES_HAM(-2.80)[99.14%]; NEURAL_HAM_LONG(-1.00)[-1.000]; R_DKIM_ALLOW(-0.20)[suse.de:s=susede2_rsa,suse.de:s=susede2_ed25519]; NEURAL_HAM_SHORT(-0.20)[-0.999]; MIME_GOOD(-0.10)[text/plain]; MX_GOOD(-0.01)[]; RCVD_VIA_SMTP_AUTH(0.00)[]; MISSING_XM_UA(0.00)[]; MIME_TRACE(0.00)[0:+]; ARC_NA(0.00)[]; TO_DN_SOME(0.00)[]; MID_RHS_MATCH_FROM(0.00)[]; RCVD_TLS_ALL(0.00)[]; RCPT_COUNT_FIVE(0.00)[6]; FROM_EQ_ENVFROM(0.00)[]; FROM_HAS_DN(0.00)[]; FUZZY_BLOCKED(0.00)[rspamd.com]; RCVD_COUNT_TWO(0.00)[2]; TO_MATCH_ENVRCPT_ALL(0.00)[]; DBL_BLOCKED_OPENRESOLVER(0.00)[suse.de:email,suse.de:dkim,suse.de:mid]; DKIM_SIGNED(0.00)[suse.de:s=susede2_rsa,suse.de:s=susede2_ed25519]; DKIM_TRACE(0.00)[suse.de:+] X-Rspamd-Server: rspamd2.dmz-prg2.suse.org X-Rspamd-Action: no action Received-SPF: pass client-ip=2a07:de40:b251:101:10:150:64:2; envelope-from=farosas@suse.de; helo=smtp-out2.suse.de X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, 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+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org yong.huang@smartx.com writes: > From: Hyman Huang > > When VM is configured with huge memory, the current throttle logic > doesn't look like to scale, because migration_trigger_throttle() > is only called for each iteration, so it won't be invoked for a long > time if one iteration can take a long time. > > The periodic dirty sync aims to fix the above issue by synchronizing > the ramblock from remote dirty bitmap and, when necessary, triggering > the CPU throttle multiple times during a long iteration. > > This is a trade-off between synchronization overhead and CPU throttle > impact. > > Signed-off-by: Hyman Huang Reviewed-by: Fabiano Rosas