From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Cyrus-Session-Id: sloti22d1t05-3124706-1524577114-6-13756315910628874499 X-Sieve: CMU Sieve 3.0 X-Spam-known-sender: no X-Spam-score: 0.0 X-Spam-hits: BAYES_00 -1.9, MAILING_LIST_MULTI -1, ME_NOAUTH 0.01, RCVD_IN_DNSWL_HI -5, LANGUAGES en, BAYES_USED global, SA_VERSION 3.4.0 X-Spam-source: IP='209.132.180.67', Host='vger.kernel.org', Country='US', FromHeader='org', MailFrom='org' X-Spam-charsets: plain='us-ascii' X-Resolved-to: greg@kroah.com X-Delivered-to: greg@kroah.com X-Mail-from: linux-api-owner@vger.kernel.org ARC-Seal: i=1; a=rsa-sha256; cv=none; d=messagingengine.com; s=fm2; t= 1524577113; b=T6hq/s0/yKdqHKyUtExQfqddNV8NpIqipjou0k1M4/xn7zaJgO K3ifpYrW8D2jTVwMSFcJI+MAuLCd7sxG3A15gc9xP/q8nnok9mHQ+4xT65LuAAc3 NAUhu8c2KiGP8k+0H/1MJbJ566sgjQe4VpPBn+4v7hLfmkwDqnhmh9W3GpML8o1z 7KH+RUPRQciNXt6e0JZ7EjoQfUTvAGN6Gbk1ot5XaD8camKVp26YoDqv0ZUKcI01 FPx7rSRfww99uA6HG8oMhwvjeu9OWZikI1mzcvTPTI4xppf5J22NM4IOrTRe6pk8 iYL3xjT+Wt/EqFbM4p0lEh04gHbp9xV4oEMw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=date:from:to:cc:subject:message-id :references:mime-version:content-type:in-reply-to:sender :list-id; s=fm2; t=1524577113; bh=LhXxFheypIY3H9qt2fivM+o4+nbq3q MXAJ1nKf86aeI=; b=m6fYAo9hVNJuTGPb0DGdFymZDkJmAxyR+cC6JOR3u+Xym7 ZTLtc5/KrV9N+xtdkLFdIgKBz4f3IEHi4TBxacB/XqfA7YRSVmq2Cp4SY1zp51KT 8alJcLKIH5DEWGtl+3Yy63AwWmHzF+9zZOBStju+3h0g7f8q6FL9C5Debt6uWnRJ EMcHBEQF8ssp682QCV6O1NSycuMd9qEKVQJIJyF4C7M/HjPjTfDO/oJbhlZFj9ew wrWBVRo//k3xCfBpK5pQnQogiHx+90HJfxdTQsCfMDZ7hT6FkoAZbsiYmIUv+iDm T52YmncwKBNRPJpoIH5FaQqgX0oCuglcSc1O0+TQ== ARC-Authentication-Results: i=1; mx6.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=kernel.org; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=linux-api-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=orgdomain_pass (Domain org match); x-cm=none score=0; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=kernel.org header.result=pass header_is_org_domain=yes; x-vs=clean score=-100 state=0 Authentication-Results: mx6.messagingengine.com; arc=none (no signatures found); dkim=none (no signatures found); dmarc=none (p=none,has-list-id=yes,d=none) header.from=kernel.org; iprev=pass policy.iprev=209.132.180.67 (vger.kernel.org); spf=none smtp.mailfrom=linux-api-owner@vger.kernel.org smtp.helo=vger.kernel.org; x-aligned-from=orgdomain_pass (Domain org match); x-cm=none score=0; x-ptr=pass x-ptr-helo=vger.kernel.org x-ptr-lookup=vger.kernel.org; x-return-mx=pass smtp.domain=vger.kernel.org smtp.result=pass smtp_org.domain=kernel.org smtp_org.result=pass smtp_is_org_domain=no header.domain=kernel.org header.result=pass header_is_org_domain=yes; x-vs=clean score=-100 state=0 X-ME-VSCategory: clean X-CM-Envelope: MS4wfP9BAnEkpk4W21Sf6SUmibmSn0EnW4m1MNQgqkOER2eKJ+ddEr9ohjvVSaAA7+3pqJ3LJNtHTEgo6btDJNAw3le43KQm0nEK8W8zfv6P22vtpivV52EO CiRUGpChKGLLlauMQkjrZiKnSsFJy6vKxkZh4gdiz+f8aEMsbsYk/tRJ45A31h2aP9DzhUmpLrrDoGv0N85tXFCv3fQkkQqARDpZb5oY2dwdEKuq3vhAcRDi X-CM-Analysis: v=2.3 cv=FKU1Odgs c=1 sm=1 tr=0 a=UK1r566ZdBxH71SXbqIOeA==:117 a=UK1r566ZdBxH71SXbqIOeA==:17 a=kj9zAlcOel0A:10 a=Kd1tUaAdevIA:10 a=VwQbUJbxAAAA:8 a=cDQm2WSucXWwO-Ly-boA:9 a=CjuIK1q_8ugA:10 a=x8gzFH9gYPwA:10 a=AjGcO6oz07-iQ99wixmX:22 X-ME-CMScore: 0 X-ME-CMCategory: none Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934416AbeDXNhu (ORCPT ); Tue, 24 Apr 2018 09:37:50 -0400 Received: from mx2.suse.de ([195.135.220.15]:52761 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933250AbeDXNhr (ORCPT ); Tue, 24 Apr 2018 09:37:47 -0400 Date: Tue, 24 Apr 2018 07:37:40 -0600 From: Michal Hocko To: Mike Kravetz Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-api@vger.kernel.org, Reinette Chatre , Christopher Lameter , Guy Shattah , Anshuman Khandual , Michal Nazarewicz , Vlastimil Babka , David Nellans , Laura Abbott , Pavel Machek , Dave Hansen , Andrew Morton Subject: Re: [PATCH 2/3] mm: add find_alloc_contig_pages() interface Message-ID: <20180424133740.GH17484@dhcp22.suse.cz> References: <20180417020915.11786-1-mike.kravetz@oracle.com> <20180417020915.11786-3-mike.kravetz@oracle.com> <20180423000943.GO17484@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-api-owner@vger.kernel.org X-Mailing-List: linux-api@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-Mailing-List: linux-kernel@vger.kernel.org List-ID: On Sun 22-04-18 21:22:07, Mike Kravetz wrote: > On 04/22/2018 05:09 PM, Michal Hocko wrote: [... > > Also do we want to check other usual suspects? E.g. PageReserved? And > > generally migrateable pages if page count > 0. Or do we want to leave > > everything to the alloc_contig_range? > > I think you proposed something like the above with limited checking at > some time in the past. In my testing, allocations were more likely to > succeed if we did limited testing here and let alloc_contig_range take > a shot at migration/allocation. There really are two ways to approach > this, do as much checking up front or let it be handled by alloc_contig_range. OK, it would be great to have a comment mentioning that. The discrepancy will just hit eyes [...] > Unless I am missing something, calls to alloc_contig range need to have > a size that is a multiple of page block. This is because isolation needs > to take place at a page block level. We can easily 'round up' and release > excess pages. I am not sure but can we simply leave a part of the page block behind? I mean it might have a misleading migrate type but that shouldn't matter much, no? Thanks! -- Michal Hocko SUSE Labs