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 7CD27C71136 for ; Mon, 16 Jun 2025 20:36:29 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1uRGYP-0000KA-W6; Mon, 16 Jun 2025 16:35:42 -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 1uRGYO-0000Jl-CR for qemu-devel@nongnu.org; Mon, 16 Jun 2025 16:35:40 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1uRGYL-0007Tt-1u for qemu-devel@nongnu.org; Mon, 16 Jun 2025 16:35:40 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1750106126; h=from:from:reply-to:subject:subject: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=7r9gGAo00UxhvZgMwQIm7BZfgRdhCpGsmwEG8EjxjQQ=; b=feSKP3zaF7LLxJOKhUtildCk1zdU6ObF7tZjylmZe4tjOvecXo1Zq0HCcNJ1RP3NsaFKIO lsLKWjDc3TChGJEfkYOOGfTE8ot98WHlZb/FJ5Y+wHF6kr86L3pDsBhDpWnxHr5+EIUlw3 QrvdTaVdV6VPoWUs+DJrX6yMkIZHf5I= Received: from mail-qt1-f200.google.com (mail-qt1-f200.google.com [209.85.160.200]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-21-JRN9SmI_OD2ER3b_B1Hy_A-1; Mon, 16 Jun 2025 16:35:25 -0400 X-MC-Unique: JRN9SmI_OD2ER3b_B1Hy_A-1 X-Mimecast-MFC-AGG-ID: JRN9SmI_OD2ER3b_B1Hy_A_1750106124 Received: by mail-qt1-f200.google.com with SMTP id d75a77b69052e-4a589edc51aso119779661cf.0 for ; Mon, 16 Jun 2025 13:35:24 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1750106124; x=1750710924; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=7r9gGAo00UxhvZgMwQIm7BZfgRdhCpGsmwEG8EjxjQQ=; b=axQsQRLBrl58J0lNp7hos42THmTjWN8LDHdACS5kr53bQ+KhSu3hQA16R3Tja5VG2r PpwO/up1pCy9OvlfHuSh387qyfHqOXM2isOz5X+MZOWlv7EswS3NRqUWOFzWr2KsQtZB dmqWv4B+lxz/gVgUF+xtIUJWSljW8bcqqSfBsqUG42kiWx+F91Y7nwz9C97gDRIjw+yK h7ecL4jwvq46US1+l+4+4hyjKQH0C9rxcaqzUt0Dqkz2HB8X0vcdoGOe6KbpLeiRuos5 HxC7PPi4VAq0X7dCwvFUdeRbu7lToizjsWlixe5TcjXeS1nLC8dNCOeU/QFPhExoe5G5 dXlw== X-Forwarded-Encrypted: i=1; AJvYcCXBam5Nxgqza5oulCXrtMMKxgFGVXjY426uBr+mwikvwXABsGMIBQoBxNDyGXjsyOF98W1fn/hPdVdm@nongnu.org X-Gm-Message-State: AOJu0YwNAJLo7nsL848D7BkFaF92nXvPoBXy9b9Vjeb4uB7ZAsLEOGjC xboQwayuyO8TkGBHwZRVCaZpeQxVZ7slSp7VHymOZFA7TYcvpuUpK9k+zTcqB34v0YAgTCFttHq Zq4s9K3onc8rVcTTPfeAQ0F1BUJRbMY4aHOfm2lJcz0Je+psBdY0HHfiP X-Gm-Gg: ASbGncv7fj8xOpnhK7IDsaMTluWVr0JXVg15VNV4nEhzuRQc60z+Fpwi6LsH1tDzHUl KKUuNbQMVwC4lBWOLJQtQc7ef4b0o4xaolLgzKQG6QwO0ZXbQ25duQ6UlJAkkfcv5OfBNrLHh+s lAR63nYhXXynySVVD5dPlk6zQqiH0/E1rge5FGpuKekUaRpHsWhBo72+PlGRwqPWfzf+i51BH5w uCb5HpeDqdI4IbUcI4i7VUAY2Vp/+0mvxAnqfFHSfaowdSllNpDwoetIAHHhutTp5M9wxHTzu4q O5kmd8s3vfF24g== X-Received: by 2002:a05:622a:130d:b0:49b:eb1d:18ad with SMTP id d75a77b69052e-4a73c5ad40emr170189981cf.41.1750106124393; Mon, 16 Jun 2025 13:35:24 -0700 (PDT) X-Google-Smtp-Source: AGHT+IEEpY3iXRe77Sfw48RrdL+eJo47RxNAL91CjjGKCa91pzaeXboyZxXY77vIzxPpxvl5AdKjvQ== X-Received: by 2002:a05:622a:130d:b0:49b:eb1d:18ad with SMTP id d75a77b69052e-4a73c5ad40emr170189241cf.41.1750106123769; Mon, 16 Jun 2025 13:35:23 -0700 (PDT) Received: from x1.local ([85.131.185.92]) by smtp.gmail.com with ESMTPSA id d75a77b69052e-4a72a2e8964sm52654231cf.19.2025.06.16.13.35.21 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 16 Jun 2025 13:35:22 -0700 (PDT) Date: Mon, 16 Jun 2025 16:35:18 -0400 From: Peter Xu To: "Chaney, Ben" Cc: David Hildenbrand , "Michael S. Tsirkin" , "yury-kotov@yandex-team.ru" , "dgilbert@redhat.com" , "beata.michalska@linaro.org" , "richard.henderson@linaro.org" , "alex.bennee@linaro.org" , "peter.maydell@linaro.org" , "junyan.he@intel.com" , "imammedo@redhat.com" , "qemu-devel@nongnu.org" , "pbonzini@redhat.com" , "philmd@linaro.org" , "xiaoguangrong.eric@gmail.com" , "Tottenham, Max" , "Hunt, Joshua" , "Glasgall, Anna" , "qemu-stable@nongnu.org" Subject: Re: [Patch] Don't sync volatile memory Message-ID: References: <7987BFFC-D46A-4BAB-8973-F30E6689E05F@akamai.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <7987BFFC-D46A-4BAB-8973-F30E6689E05F@akamai.com> Received-SPF: pass client-ip=170.10.129.124; envelope-from=peterx@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -39 X-Spam_score: -4.0 X-Spam_bar: ---- X-Spam_report: (-4.0 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1.892, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.001, RCVD_IN_VALIDITY_RPBL_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+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org On Mon, Jun 16, 2025 at 07:43:02PM +0000, Chaney, Ben wrote: > Not all pmem regions are backed by non-volatile memory. Syncing volatile > memory provides no benefit, but can cause performance issues is some > cases. Only sync memory that is marked as non-volatile. > > Fixes: bd108a44bc29 (migration: ram: Switch to ram block writeback) Do you plan to work on qemu in the future? If so, I suggest you go through this and repost: https://www.qemu.org/docs/master/devel/submitting-a-patch.html If the answer is no, I'll at least need your Signed-off-By: line here, then I can fix all the rest for you. The patch looks ok though. Thanks, > > --- > migration/ram.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > 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; > > RAMBLOCK_FOREACH_NOT_IGNORED(rb) { > - qemu_ram_block_writeback(rb); > + if (memory_region_is_nonvolatile(rb->mr)) { > + qemu_ram_block_writeback(rb); > + } > } > > xbzrle_load_cleanup(); > -- > 2.40.1 > > > > -- Peter Xu