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 X-Spam-Level: X-Spam-Status: No, score=-15.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6CDD7C433E0 for ; Thu, 25 Feb 2021 08:18:06 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 9BD7164E4D for ; Thu, 25 Feb 2021 08:18:05 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9BD7164E4D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=huawei.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:52582 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lFBqW-0002Wd-1k for qemu-devel@archiver.kernel.org; Thu, 25 Feb 2021 03:18:04 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:59626) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lFBpq-00024J-90 for qemu-devel@nongnu.org; Thu, 25 Feb 2021 03:17:22 -0500 Received: from szxga02-in.huawei.com ([45.249.212.188]:2130) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lFBpn-0004Y9-2R for qemu-devel@nongnu.org; Thu, 25 Feb 2021 03:17:21 -0500 Received: from DGGEMM406-HUB.china.huawei.com (unknown [172.30.72.55]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4DmQZj4RqRz5WWk; Thu, 25 Feb 2021 16:15:25 +0800 (CST) Received: from dggema765-chm.china.huawei.com (10.1.198.207) by DGGEMM406-HUB.china.huawei.com (10.3.20.214) with Microsoft SMTP Server (TLS) id 14.3.498.0; Thu, 25 Feb 2021 16:17:02 +0800 Received: from [10.174.185.210] (10.174.185.210) by dggema765-chm.china.huawei.com (10.1.198.207) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2106.2; Thu, 25 Feb 2021 16:17:01 +0800 Subject: Re: [PATCH 1/3] migration/ram: Modify the code comment of ram_save_host_page() To: David Edmondson , Juan Quintela , "Dr . David Alan Gilbert" , "open list:All patches CC here" References: <20210223021646.500-1-jiangkunkun@huawei.com> <20210223021646.500-2-jiangkunkun@huawei.com> From: Kunkun Jiang Message-ID: Date: Thu, 25 Feb 2021 16:16:36 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.4.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US X-Originating-IP: [10.174.185.210] X-ClientProxiedBy: dggeme709-chm.china.huawei.com (10.1.199.105) To dggema765-chm.china.huawei.com (10.1.198.207) X-CFilter-Loop: Reflected Received-SPF: pass client-ip=45.249.212.188; envelope-from=jiangkunkun@huawei.com; helo=szxga02-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, NICE_REPLY_A=-0.001, 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+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 2021/2/25 6:53, David Edmondson wrote: > On Tuesday, 2021-02-23 at 10:16:43 +08, Kunkun Jiang wrote: > >> 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, PageSearchStatus *pss, >> } >> >> /** >> - * 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. > How about: > > * Send dirty pages between pss->page and either the end of that page or > * the used_length of the RAMBlock, whichever is smaller. > * > * Note that if the host page is a huge page, pss->page may be in the > * middle of that page. Thank you. It looks concise and comprehensive. Best Regards Kunkun Jiang >> * >> * Returns the number of pages written or negative on error >> * >> -- >> 2.23.0 > dme.