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_PASS, USER_AGENT_MUTT autolearn=unavailable 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 63393C46460 for ; Tue, 7 May 2019 17:32:27 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 2448F20989 for ; Tue, 7 May 2019 17:32:27 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2448F20989 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 CA5CD6B0005; Tue, 7 May 2019 13:32:26 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id C557D6B0007; Tue, 7 May 2019 13:32:26 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B1EF86B0008; Tue, 7 May 2019 13:32:26 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from mail-ed1-f71.google.com (mail-ed1-f71.google.com [209.85.208.71]) by kanga.kvack.org (Postfix) with ESMTP id 667496B0005 for ; Tue, 7 May 2019 13:32:26 -0400 (EDT) Received: by mail-ed1-f71.google.com with SMTP id p14so5833189edc.4 for ; Tue, 07 May 2019 10:32:26 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-original-authentication-results:x-gm-message-state:date:from:to :cc:subject:message-id:references:mime-version:content-disposition :in-reply-to:user-agent; bh=xUFlq6ieDM/DBTmG0i31Huyc63kW9fpny2rN0ro6jaE=; b=Uv6/K10+NmMyziCT/iNzWgyQPWx9YngMSfxdcO1pRSrMXJmWz8xDetUsHdvAsXIe7z LS1SrXyePLto4hTJOw03p+V8AF6P9wT10h+P7VWcc2UJkNC/WBtifJ8lFm4NrY7uc8KP JaSlcKitNrW1VTlKT3TbkWPpQgl2PyTiGFaRjQVC199LYJyle9tNndttAIOMfFoUs7B1 nhm5TsuSsJqeE3NgiEX+fWACH5xmzSnpdMTKKSlFqMduwImYJFkX5MIVV7yLy6g3Gb/P FmW4EKuQ9Ldba1lGzQnUtr5cEZfkVZexHw21RyCYnJUsbvFzUzTIppBdvZ8mfTtl4gHl xbmA== X-Original-Authentication-Results: mx.google.com; spf=softfail (google.com: domain of transitioning mhocko@kernel.org does not designate 195.135.220.15 as permitted sender) smtp.mailfrom=mhocko@kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=kernel.org X-Gm-Message-State: APjAAAVtxEGuo33mQ8v5X4ltKDmm9oW7avuQxyr8pwHxmdDxNazB6Nk3 MawA3IGaN7eWbaTK1u44wNMIPFY0osrNtL1wA4/SIGXF1yegLm57Nk8Efblv0C3yQnDwEwRPsfo gwo42m4RZ6zMvuWdxMoKAzI6g97X0LVeYHZS01EtwZHCPiTE2uaeBERgI0P/Sf+g= X-Received: by 2002:aa7:d381:: with SMTP id x1mr35000890edq.251.1557250345947; Tue, 07 May 2019 10:32:25 -0700 (PDT) X-Google-Smtp-Source: APXvYqxb2UNX6GwGhUeV+GJPXtjYR2IbTOnewYQesab6O18peUX/7t11/Zruh8AjMozzS8ymWGeD X-Received: by 2002:aa7:d381:: with SMTP id x1mr35000822edq.251.1557250345322; Tue, 07 May 2019 10:32:25 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1557250345; cv=none; d=google.com; s=arc-20160816; b=QvksfPd96/orj9r4PVrcLz3v9ssp487ttira1tS3ZpktVOXykWYImyumaI18TCYFPZ NBTRIOTggoxKZeu2C9gQPXWFjYVknFYYJu8DQ0u+WDsq8IvvzNzk4FotOhTbQ5NN31yG Ya+lDPUfgLLsozOMrNJvV5prYVRidmw5PtuwsALaG2prW6lUDHjsxkW7RwxnS6M7q+Bb HSvqa8PXTfY3QVOeEpMy7XD8jBEABknt16m8AsnyMcampGipTiNWpQxO+roqbzSd4lVB o92Pf/Xg4tUpnOiH0Gj6zq+7L40rtVSe7bJs5ytGJMvuJg3haSB0r5KZjr8AA60mVPB8 xcWQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=user-agent:in-reply-to:content-disposition:mime-version:references :message-id:subject:cc:to:from:date; bh=xUFlq6ieDM/DBTmG0i31Huyc63kW9fpny2rN0ro6jaE=; b=iROkN/4nFq0hU7KUrgdDwnW9n0ltuLcXH7f96cnTvK64Wm48jjw1yFKptqgWQ8ysgw J8otpLC+MVxztckTDGQ7D5mrwUgfwAUI0JWECiRh3jZbRFEQNirZhfLpahSDwEmquSqT hEm9aEfbkSqtPHavo3IRk39fNftMvYD1gRxt04KIs+DpPhofJxfzGmAN40JJT+vZ/Ijp QakiiP91kvostUXFLnCFJ1pTYcb0uBY1+FLI+gFQAhZtLaQc7DUo4XXXhvEo/GPXNR9y tq6Dlr7VsGYuEblNURSaYb+uB8bsAvgxjHELPrmGMcIMXhu6fq/swByQdHCc3etMod0Q QIPg== ARC-Authentication-Results: i=1; mx.google.com; spf=softfail (google.com: domain of transitioning mhocko@kernel.org does not designate 195.135.220.15 as permitted sender) smtp.mailfrom=mhocko@kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: from mx1.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id z10si6605940edl.150.2019.05.07.10.32.25 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 07 May 2019 10:32:25 -0700 (PDT) Received-SPF: softfail (google.com: domain of transitioning mhocko@kernel.org does not designate 195.135.220.15 as permitted sender) client-ip=195.135.220.15; Authentication-Results: mx.google.com; spf=softfail (google.com: domain of transitioning mhocko@kernel.org does not designate 195.135.220.15 as permitted sender) smtp.mailfrom=mhocko@kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=kernel.org X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id E641BAEA3; Tue, 7 May 2019 17:32:24 +0000 (UTC) Date: Tue, 7 May 2019 19:32:24 +0200 From: Michal Hocko To: Sasha Levin Cc: Linus Torvalds , Alexander Duyck , LKML , stable , Mikhail Zaslonko , Gerald Schaefer , Mikhail Gavrilov , Dave Hansen , Alexander Duyck , Pasha Tatashin , Martin Schwidefsky , Heiko Carstens , Andrew Morton , Sasha Levin , linux-mm Subject: Re: [PATCH AUTOSEL 4.14 62/95] mm, memory_hotplug: initialize struct pages for the full memory section Message-ID: <20190507173224.GS31017@dhcp22.suse.cz> References: <20190507053826.31622-1-sashal@kernel.org> <20190507053826.31622-62-sashal@kernel.org> <20190507170208.GF1747@sasha-vm> <20190507171806.GG1747@sasha-vm> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190507171806.GG1747@sasha-vm> User-Agent: Mutt/1.10.1 (2018-07-13) 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 Tue 07-05-19 13:18:06, Sasha Levin wrote: > On Tue, May 07, 2019 at 10:15:19AM -0700, Linus Torvalds wrote: > > On Tue, May 7, 2019 at 10:02 AM Sasha Levin wrote: > > > > > > I got it wrong then. I'll fix it up and get efad4e475c31 in instead. > > > > Careful. That one had a bug too, and we have 891cb2a72d82 ("mm, > > memory_hotplug: fix off-by-one in is_pageblock_removable"). > > > > All of these were *horribly* and subtly buggy, and might be > > intertwined with other issues. And only trigger on a few specific > > machines where the memory map layout is just right to trigger some > > special case or other, and you have just the right config. > > > > It might be best to verify with Michal Hocko. Michal? > > Michal, is there a testcase I can plug into kselftests to make sure we > got this right (and don't regress)? We care a lot about memory hotplug > working right. As said in other email. The memory hotplug tends to work usually. It takes unexpected memory layouts which trigger corner cases. This makes testing really hard. -- Michal Hocko SUSE Labs