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=-5.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS 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 0804AC433E8 for ; Fri, 24 Jul 2020 02:36:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DB3B6207DF for ; Fri, 24 Jul 2020 02:36:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1595558164; bh=223v+GvHabeD9/eJz4SlfQmngb87VspYTvdYp60L5p0=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=xJRHx49mb5kUIQMGm1SW4nXo8qqIen9PJ4NqDAbs7dcHws/Qg1R3ughdAbkQOZ44y OPpv7Szqa3k0qZSjfZykKeEEXtae3YPYfdgR5WXR8x2QIqURVPwUTXMF6a4wbpYZ1n NklpJXLjYjFtYHp22jNXEInsrcVPslzgm/uebiAs= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726711AbgGXCgC (ORCPT ); Thu, 23 Jul 2020 22:36:02 -0400 Received: from mail.kernel.org ([198.145.29.99]:35310 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726437AbgGXCgB (ORCPT ); Thu, 23 Jul 2020 22:36:01 -0400 Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 92AD62065E; Fri, 24 Jul 2020 02:36:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1595558161; bh=223v+GvHabeD9/eJz4SlfQmngb87VspYTvdYp60L5p0=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=PRGZ/sQaneFPcE/dr8WewYV92zNf0JrkuKmUby4KKmxYk5Wk3t9fyobEZhizw2ZGE nUNrYrJ7SEy0F0/pBhR6kbH1cstLZq2zsDNLMSP34YP/le01QpVCwXnH8pPM5Xw0Cx ThElvUD47Ez0n09WQ9SFdlnXfRGIcsFlsJEaiDN0= Date: Thu, 23 Jul 2020 19:36:00 -0700 From: Andrew Morton To: Joonsoo Kim Cc: Linux Memory Management List , LKML , kernel-team@lge.com, Vlastimil Babka , Christoph Hellwig , Roman Gushchin , Mike Kravetz , Naoya Horiguchi , Michal Hocko , "Aneesh Kumar K . V" , Joonsoo Kim , stable@vger.kernel.org Subject: Re: [PATCH v2] mm/page_alloc: fix memalloc_nocma_{save/restore} APIs Message-Id: <20200723193600.28e3eedd00925b22f7ca9780@linux-foundation.org> In-Reply-To: References: <1595468942-29687-1-git-send-email-iamjoonsoo.kim@lge.com> <20200723180814.acde28b92ce6adc785a79120@linux-foundation.org> X-Mailer: Sylpheed 3.5.1 (GTK+ 2.24.31; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 24 Jul 2020 11:23:52 +0900 Joonsoo Kim wrote: > > > Second, clearing __GFP_MOVABLE in current_gfp_context() has a side effect > > > to exclude the memory on the ZONE_MOVABLE for allocation target. > > > > More whoops. > > > > Could we please have a description of the end-user-visible effects of > > this change? Very much needed when proposing a -stable backport, I think. > > In fact, there is no noticeable end-user-visible effect since the fallback would > cover the problematic case. It's mentioned in the commit description. Perhap, > performance would be improved due to reduced retry and more available memory > (we can use ZONE_MOVABLE with this patch) but it would be neglectable. > > > d7fefcc8de9147c is over a year old. Why did we only just discover > > this? This makes one wonder how serious those end-user-visible effects > > are? > > As mentioned above, there is no visible problem to the end-user. OK, thanks. In that case, I don't believe that a stable backport is appropriate? (Documentation/process/stable-kernel-rules.rst)