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=-19.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,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 056A5C433DB for ; Tue, 22 Dec 2020 08:50:07 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 8D9F12076B for ; Tue, 22 Dec 2020 08:50:06 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8D9F12076B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id F0C546B009E; Tue, 22 Dec 2020 03:50:05 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id EBD6E6B009F; Tue, 22 Dec 2020 03:50:05 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id DAA398D0009; Tue, 22 Dec 2020 03:50:05 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0148.hostedemail.com [216.40.44.148]) by kanga.kvack.org (Postfix) with ESMTP id C57B86B009E for ; Tue, 22 Dec 2020 03:50:05 -0500 (EST) Received: from smtpin03.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 8FB3F180ACEEE for ; Tue, 22 Dec 2020 08:50:05 +0000 (UTC) X-FDA: 77620295970.03.dirt36_170571a2745e Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin03.hostedemail.com (Postfix) with ESMTP id D515C28A4EA for ; Tue, 22 Dec 2020 08:50:04 +0000 (UTC) X-HE-Tag: dirt36_170571a2745e X-Filterd-Recvd-Size: 6447 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [216.205.24.124]) by imf11.hostedemail.com (Postfix) with ESMTP for ; Tue, 22 Dec 2020 08:50:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1608627003; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=uMHSD2oK/hpBE1SWjefvZVCPS8CnbnjDm/tKLudlcaA=; b=YhqkGeADvSL7wEETJ17C6mHYpG/If2yUi89GWGffPCYQ32LkPAn1f0O93WXzstScUvF6mO lP9ySxez6beRwRd7sMl3PudIKmulQ+CJpiTnjLY1VoIsUe8E/u6336X36M6aWZHF7z59tM o5ps6jYKISiz++2aiY1S88sZf1DE17k= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-261-_ixAoxX4N3C5tAyWFegXGQ-1; Tue, 22 Dec 2020 03:49:59 -0500 X-MC-Unique: _ixAoxX4N3C5tAyWFegXGQ-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 4F120180A08A; Tue, 22 Dec 2020 08:49:57 +0000 (UTC) Received: from [10.36.113.220] (ovpn-113-220.ams2.redhat.com [10.36.113.220]) by smtp.corp.redhat.com (Postfix) with ESMTP id E001D5B6A8; Tue, 22 Dec 2020 08:49:50 +0000 (UTC) Subject: Re: [RFC PATCH 3/3] mm: support free hugepage pre zero out From: David Hildenbrand To: Alexander Duyck , Mel Gorman , Andrew Morton , Andrea Arcangeli , Dan Williams , "Michael S. Tsirkin" , Jason Wang , Dave Hansen , Michal Hocko , Liang Li , Mike Kravetz , Liang Li , linux-mm@kvack.org, linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, qemu-devel@nongnu.org References: <20201222074910.GA30051@open-light-1.localdomain> <585791f4-4b41-5e73-296e-691d5478a915@redhat.com> Organization: Red Hat GmbH Message-ID: Date: Tue, 22 Dec 2020 09:49:49 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.5.0 MIME-Version: 1.0 In-Reply-To: <585791f4-4b41-5e73-296e-691d5478a915@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 22.12.20 09:31, David Hildenbrand wrote: > On 22.12.20 08:49, Liang Li wrote: >> This patch add support of pre zero out free hugepage, we can use >> this feature to speed up page population and page fault handing. >> >> Cc: Alexander Duyck >> Cc: Mel Gorman >> Cc: Andrea Arcangeli >> Cc: Dan Williams >> Cc: Dave Hansen >> Cc: David Hildenbrand >> Cc: Michal Hocko >> Cc: Andrew Morton >> Cc: Alex Williamson >> Cc: Michael S. Tsirkin >> Cc: Jason Wang >> Cc: Mike Kravetz >> Cc: Liang Li >> Signed-off-by: Liang Li >> --- >> mm/page_prezero.c | 17 +++++++++++++++++ >> 1 file changed, 17 insertions(+) >> >> diff --git a/mm/page_prezero.c b/mm/page_prezero.c >> index c8ce720bfc54..dff4e0adf402 100644 >> --- a/mm/page_prezero.c >> +++ b/mm/page_prezero.c >> @@ -26,6 +26,7 @@ static unsigned long delay_millisecs = 1000; >> static unsigned long zeropage_enable __read_mostly; >> static DEFINE_MUTEX(kzeropaged_mutex); >> static struct page_reporting_dev_info zero_page_dev_info; >> +static struct page_reporting_dev_info zero_hugepage_dev_info; >> >> inline void clear_zero_page_flag(struct page *page, int order) >> { >> @@ -69,9 +70,17 @@ static int start_kzeropaged(void) >> zero_page_dev_info.delay_jiffies = msecs_to_jiffies(delay_millisecs); >> >> err = page_reporting_register(&zero_page_dev_info); >> + >> + zero_hugepage_dev_info.report = zero_free_pages; >> + zero_hugepage_dev_info.mini_order = mini_page_order; >> + zero_hugepage_dev_info.batch_size = batch_size; >> + zero_hugepage_dev_info.delay_jiffies = msecs_to_jiffies(delay_millisecs); >> + >> + err |= hugepage_reporting_register(&zero_hugepage_dev_info); >> pr_info("Zero page enabled\n"); >> } else { >> page_reporting_unregister(&zero_page_dev_info); >> + hugepage_reporting_unregister(&zero_hugepage_dev_info); >> pr_info("Zero page disabled\n"); >> } >> >> @@ -90,7 +99,15 @@ static int restart_kzeropaged(void) >> zero_page_dev_info.batch_size = batch_size; >> zero_page_dev_info.delay_jiffies = msecs_to_jiffies(delay_millisecs); >> >> + hugepage_reporting_unregister(&zero_hugepage_dev_info); >> + >> + zero_hugepage_dev_info.report = zero_free_pages; >> + zero_hugepage_dev_info.mini_order = mini_page_order; >> + zero_hugepage_dev_info.batch_size = batch_size; >> + zero_hugepage_dev_info.delay_jiffies = msecs_to_jiffies(delay_millisecs); >> + >> err = page_reporting_register(&zero_page_dev_info); >> + err |= hugepage_reporting_register(&zero_hugepage_dev_info); >> pr_info("Zero page enabled\n"); >> } >> >> > > Free page reporting in virtio-balloon doesn't give you any guarantees > regarding zeroing of pages. Take a look at the QEMU implementation - > e.g., with vfio all reports are simply ignored. > > Also, I am not sure if mangling such details ("zeroing of pages") into > the page reporting infrastructure is a good idea. > Oh, now I get what you are doing here, you rely on zero_free_pages of your other patch series and are not relying on virtio-balloon free page reporting to do the zeroing. You really should have mentioned that this patch series relies on the other one and in which way. -- Thanks, David / dhildenb