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=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 9E9E5C43215 for ; Mon, 25 Nov 2019 11:47:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7726D2082F for ; Mon, 25 Nov 2019 11:47:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1574682433; bh=ej9AvV7UyrqQJj2q1JSOblTD8oMNvMOkTOyfuFr8cTs=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=l6AMNQzlxDaW9eqNqVVxKuZYjde6trnZ+4uXCvaT7Wks0bY0Z8kK3LBLUxGjQ3Zac pv+X7Xc4t28zv+es81xVrNaS1oqT3hfQewfug3YVIJIfyXF6wGVdZYyJ0DN7xksZgX 3JdzS8aTYenOTkWIMZ3Tg3o3rHmDj79lYjK7VHTs= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727378AbfKYLrM (ORCPT ); Mon, 25 Nov 2019 06:47:12 -0500 Received: from mail-wr1-f65.google.com ([209.85.221.65]:42187 "EHLO mail-wr1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727237AbfKYLrL (ORCPT ); Mon, 25 Nov 2019 06:47:11 -0500 Received: by mail-wr1-f65.google.com with SMTP id a15so17621489wrf.9 for ; Mon, 25 Nov 2019 03:47:10 -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=S+EEhkHcLVWZKwT8zqSpAmLXMvzyNuJC5U+oB96yAfY=; b=sxevm++HvCr1/v6JRNS39UApOmnsBgTHq3bQwMLBSRMrQNGJjNuHEIkgw4q+eQlorq p9qWLeF7Epmm2hY3pGOQojTZ4MvOx6U3Ns5spHyy+m+za+yfYBec8WH19E3EUg7nX8wq dgchBjgIotRPxsi/TN4zcbCNCtJ7E2+FiCQ2yHKU4zyzceiaqT6NjibXg2DFMr2hB38J Cu/h9P0Y90Zwd2KZaNEyVcAR7WhUlRDXRas83Waj/l+agTl7bpJKC+akNcXQMFEunsx9 mgnbfHLe2oa2EdhT429kY43Grsh5BmF5rWo7XCnWNi69te8M4tJZmpaB5SbB9KvwwH6d a0pA== X-Gm-Message-State: APjAAAXxDMSDKA3/fAHD9dYdvobUsRHuHQBT13oPCuSInKODe8xH2c83 y1m42abXBPRHmOdP4f0HMBE= X-Google-Smtp-Source: APXvYqyEESAigdr6gGonQM35wfYwuKMSmcENhp8ksP9iuV8ybf2y2gcCZTJbQ0ke0h5FD6Nxi+Optw== X-Received: by 2002:a5d:538d:: with SMTP id d13mr32994290wrv.304.1574682429742; Mon, 25 Nov 2019 03:47:09 -0800 (PST) Received: from localhost (prg-ext-pat.suse.com. [213.151.95.130]) by smtp.gmail.com with ESMTPSA id 4sm8426509wmd.33.2019.11.25.03.47.08 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 25 Nov 2019 03:47:09 -0800 (PST) Date: Mon, 25 Nov 2019 12:47:08 +0100 From: Michal Hocko To: David Rientjes Cc: Mel Gorman , Andrew Morton , Vlastimil Babka , Linus Torvalds , Andrea Arcangeli , "Kirill A. Shutemov" , Linux Kernel Mailing List , Linux-MM Subject: Re: [patch for-5.3 0/4] revert immediate fallback to remote hugepages Message-ID: <20191125114708.GI31714@dhcp22.suse.cz> References: <08a3f4dd-c3ce-0009-86c5-9ee51aba8557@suse.cz> <20191029151549.GO31513@dhcp22.suse.cz> <20191029143351.95f781f09a9fbf254163d728@linux-foundation.org> <20191105130253.GO22672@dhcp22.suse.cz> <20191106073521.GC8314@dhcp22.suse.cz> <20191113112042.GG28938@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun 24-11-19 16:10:53, David Rientjes wrote: [...] > So my question would be: if we know the previous behavior that allowed > excessive swap and recalling into compaction was deemed harmful for the > local node, why do we now believe it cannot be harmful if done for all > system memory? I have to say that I got lost in your explanation. I have already pointed this out in a previous email you didn't reply to. But the main difference to previous __GFP_THISNODE behavior is that it is used along with __GFP_NORETRY and that reduces the overall effort of the reclaim AFAIU. If that is not the case then please be _explicit_ why. Having test results from Andrea would be really appreciated of course but he seems to be too busy to do that (or maybe not interested anymore). I do not see any real reason to hold on this patch based on hand waving though. So either we have some good reasoning to argue against the patch or a good testing results or we should go ahead. As things stand right now, THP success rate went down after your last changes for _very simple_ workloads. This needs addressing which I hope we do agree on. -- Michal Hocko SUSE Labs