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=-1.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,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 5D3EBC2D0F3 for ; Thu, 2 Apr 2020 17:16:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EBECA2137B for ; Thu, 2 Apr 2020 17:16:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1585847797; bh=dsVfNTn/hVDA6Xzuu7xcrFWaWU7RKkU7JOKRN7mol7Y=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=xp6klingjaOlGXovlQ8WS+T++DUqcsUpr2+dwJsRWQJ6QtmxU6cJk2mUnybTGppXH QJFsi9HXB9DuYL5V3C4IKCaX3h9mi8QTzi2DVk+SE+xI6kmf2nWrKzKAJVeyk5wwCo lLQdKJkYMScC/YX0RD/tdjZr3hPcfUWuFzuSMe+4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388809AbgDBRQf (ORCPT ); Thu, 2 Apr 2020 13:16:35 -0400 Received: from mail-wr1-f66.google.com ([209.85.221.66]:44789 "EHLO mail-wr1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732299AbgDBRQf (ORCPT ); Thu, 2 Apr 2020 13:16:35 -0400 Received: by mail-wr1-f66.google.com with SMTP id m17so5125305wrw.11 for ; Thu, 02 Apr 2020 10:16:34 -0700 (PDT) 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; bh=wSJgn6y+TnPhKVbxYRczrw0YlPLaTZQeeEt5dFsH/O0=; b=hh6qzSOKCf/UZMT0ETCvcb28mj+Du8ZnPD/baZXs0lUklIIsqDty7xap86ohuo1BPM owRyQNj24IBcEEovPYF0lBiRuGM7c2VhEDMp+H4G2+kwbHj/wT5w1jhbBOefItQuQkKy uFvx7LqEXoRSYdS9Uvqm1jvrBysCL2jI7uakuElM4Q149lnz2MVasTRRG0L1rYoBNCfm FiF3zdZ+jpv6OsQzI0IGDsUBJamp7AYcuU8niHqcVYVZapo2vCiPrJrV1yOADYnGuxDK zVcSlkxe4/hBujj+YSzPJPxWVOFNJmB9r2SZVgMLALFn37PNqI5WwgHSNnM5z9qYyWH1 c3EQ== X-Gm-Message-State: AGi0Pubcx4ilWejcpTVabZI3XLwVnv6BNt7BRtGEnzxqo9/LgdDKHVY/ kgnfjjcp+r14H9d0QNAvj6U= X-Google-Smtp-Source: APiQypIWtH7Pfnug8iU1zL15G60DAQmAUS0fYXs9+ehtubvusYTQQj++dv8yoYgYp85u4+rIix2yIw== X-Received: by 2002:a5d:4f08:: with SMTP id c8mr4636754wru.27.1585847794165; Thu, 02 Apr 2020 10:16:34 -0700 (PDT) Received: from localhost (ip-37-188-180-223.eurotel.cz. [37.188.180.223]) by smtp.gmail.com with ESMTPSA id k3sm8396362wrw.61.2020.04.02.10.16.32 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 02 Apr 2020 10:16:33 -0700 (PDT) Date: Thu, 2 Apr 2020 19:16:31 +0200 From: Michal Hocko To: Pavel Tatashin Cc: David Hildenbrand , LKML , Andrew Morton , linux-mm , Dan Williams , Shile Zhang , Daniel Jordan , Kirill Tkhai , James Morris , Sasha Levin , Vlastimil Babka Subject: Re: [PATCH v2 2/2] mm: initialize deferred pages with interrupts enabled Message-ID: <20200402171631.GU22681@dhcp22.suse.cz> References: <20200401225723.14164-1-pasha.tatashin@soleen.com> <20200401225723.14164-3-pasha.tatashin@soleen.com> <20200402074732.GJ22681@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu 02-04-20 11:13:49, Pavel Tatashin wrote: > > > I do wonder if this change is strictly required in this patch (IOW, if > > > we could keep calling touch_nmi_watchdog() also without holding a spinlock) > > > > Exactly. I would go with your patch on top. > > > > > Anyhow, it's the right thing to do. > > Michal, > > The reason I changed it here is because in the original patch that > this patch fixes we changed cond_sched() to touch_nmi_watchdog(): > $ git show 3a2d7fa8a3d5 | grep -E '(nmi|sched)' > - cond_resched(); > + touch_nmi_watchdog(); > - cond_resched(); > + touch_nmi_watchdog(); > > So, should I move it to a separate patch or is it OK to keep it here? Having in a separate patch would be better IMO. If for nothing else, the RCU stall would be easier to see. -- Michal Hocko SUSE Labs