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=-2.5 required=3.0 tests=MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 B53E5C2D0DB for ; Mon, 20 Jan 2020 14:14:37 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 779E521835 for ; Mon, 20 Jan 2020 14:14:37 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 779E521835 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 31F5D6B066E; Mon, 20 Jan 2020 09:14:37 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 2D1766B066F; Mon, 20 Jan 2020 09:14:37 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 1E6F16B0670; Mon, 20 Jan 2020 09:14:37 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0235.hostedemail.com [216.40.44.235]) by kanga.kvack.org (Postfix) with ESMTP id 076CE6B066E for ; Mon, 20 Jan 2020 09:14:37 -0500 (EST) Received: from smtpin10.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with SMTP id C50EA8248047 for ; Mon, 20 Jan 2020 14:14:36 +0000 (UTC) X-FDA: 76398208152.10.jam99_626b583abb64e X-HE-Tag: jam99_626b583abb64e X-Filterd-Recvd-Size: 4031 Received: from mail-wr1-f68.google.com (mail-wr1-f68.google.com [209.85.221.68]) by imf40.hostedemail.com (Postfix) with ESMTP for ; Mon, 20 Jan 2020 14:14:36 +0000 (UTC) Received: by mail-wr1-f68.google.com with SMTP id q10so29736199wrm.11 for ; Mon, 20 Jan 2020 06:14:36 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=lkDkkMY1TWgj8+gYQdlaFHI7hmmwbXGQtowlL27ZgDI=; b=qiFeAK2FhEplAdRM+TT8wxX0ju953vhfV5/273qTdE6Uyv+BeJOi5ygmjB43EidW5b KVKTvfZfMmU+NJnRBT89Ci8kOOQ7wijUtS2FZ7ymCG7/hTm05IcSYa6Mu1Kc9DNZmt2Q kXBB1bOvYB+Nfvq/eQQkLKyhnFoPFPD9L6qb8kXGFnZLkHQSHRFgMGlYglnAqA2zkS98 qyxGpUUGLJlnQTEe00StrxIIOyMM2zh+6PbfV/J5ewvLWseZJ+J089lelwhGgotwoTfu wefDkuKYlsHsezOymXkmb1ZMagg8KqzgNIdWGWJHQ+5lhTTfz7bmWuUClQxBo/lkgsWy 8DAw== X-Gm-Message-State: APjAAAXzGdw6HldKJmA48hdk9R0+w5/Db6/y2vvjIbvaCJ2k+kD8ImZQ GSsWo2Dtb1mb0uLui4aZ7vU= X-Google-Smtp-Source: APXvYqz5/OtwpB21BRTDCwjNdY9uy8qzHGGRso8Ycl1SAhw43eAeI0AzOpJL6n5gnGShrtZ2EdKgaA== X-Received: by 2002:adf:fd43:: with SMTP id h3mr18440651wrs.169.1579529675281; Mon, 20 Jan 2020 06:14:35 -0800 (PST) Received: from localhost (prg-ext-pat.suse.com. [213.151.95.130]) by smtp.gmail.com with ESMTPSA id i11sm49089379wrs.10.2020.01.20.06.14.34 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 20 Jan 2020 06:14:34 -0800 (PST) Date: Mon, 20 Jan 2020 15:14:33 +0100 From: Michal Hocko To: Tianyu Lan Cc: David Hildenbrand , "lantianyu1986@gmail.com" , KY Srinivasan , Haiyang Zhang , Stephen Hemminger , "sashal@kernel.org" , "akpm@linux-foundation.org" , Michael Kelley , "linux-hyperv@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , vkuznets , "eric.devolder@oracle.com" , "vbabka@suse.cz" , "osalvador@suse.de" , Pasha Tatashin , "rppt@linux.ibm.com" Subject: Re: [EXTERNAL] Re: [RFC PATCH V2 2/10] mm: expose is_mem_section_removable() symbol Message-ID: <20200120141433.GI18451@dhcp22.suse.cz> References: <20200107130950.2983-1-Tianyu.Lan@microsoft.com> <20200107130950.2983-3-Tianyu.Lan@microsoft.com> <20200107133623.GJ32178@dhcp22.suse.cz> <99a6db0c-6d73-d982-58b3-7a0172748ae4@redhat.com> <20200114095057.GK19428@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.12.2 (2019-09-21) 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 Fri 17-01-20 16:35:03, Tianyu Lan wrote: [...] > > Could you describe your usecase in more details please? > > Hyper-V sends hot-remove request message which just contains requested > page number but not provide detail range. So Hyper-V driver needs to search > suitable memory block in system memory to return back to host if there is no > memory hot-add before. So I used the is_mem_section_removable() do such check. As David described, you would be much better of by using alloc_contig_range to find a memory that would be suitable for hotremoving without any races. -- Michal Hocko SUSE Labs