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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,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 67B36C47089 for ; Thu, 27 May 2021 09:15:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 45AB1613D4 for ; Thu, 27 May 2021 09:15:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235620AbhE0JRH (ORCPT ); Thu, 27 May 2021 05:17:07 -0400 Received: from wnew2-smtp.messagingengine.com ([64.147.123.27]:33873 "EHLO wnew2-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235589AbhE0JRG (ORCPT ); Thu, 27 May 2021 05:17:06 -0400 Received: from compute5.internal (compute5.nyi.internal [10.202.2.45]) by mailnew.west.internal (Postfix) with ESMTP id 34010F5F; Thu, 27 May 2021 05:15:30 -0400 (EDT) Received: from mailfrontend1 ([10.202.2.162]) by compute5.internal (MEProxy); Thu, 27 May 2021 05:15:31 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kroah.com; h= date:from:to:cc:subject:message-id:references:mime-version :content-type:in-reply-to; s=fm3; bh=jcYzwiykpy8reYauDRa+4H5WzJK C8nKM1Ty7GsBBKSw=; b=EY0Px+eKZeV6/mrD43SyzdTTQaRFbdsJOru9N/GtOdg lCETAQHLexUg7chWScZVp0f1xWehXBhjmIA0ogbSy9PBGBuhWwh2MiT2SNTASBPk u8H67zF9JBwTUNIYjMHa+PwFPVbSb1umVXdp/KoJQwk+kbrQ5akAd1t6SY36gsfw NH5UkPWZiENTMCcSifucLw1ov0i6F0a2Nj6bzlkOSf6YwX1fYXHFqMSVQYLPMmHf tumFU3vgF/JJ1rmrj3QTgorPLh9EqVdhbqfyaptt4qS6nsP3yR9zNNHgyWX8cl6H ZjkMcY3gTaVm3U1nzTOEWeXBAwX3n0xoD0y+5eBQFxg== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to:x-me-proxy :x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s=fm2; bh=jcYzwi ykpy8reYauDRa+4H5WzJKC8nKM1Ty7GsBBKSw=; b=rHbftXmils8cgyVch3bxNp qjdPOrkjbEftBLlMMDPaY9pZgJkCM6rNkgoTqKu5okEjLC0/3YmSyB8fF41e+AOw Thj/ZcvuvS6+tF6SPWkb0Ko8WbpTheKlicoRlj/Q7ZEaDa7/DtnBfPuH55mrjBE4 KBoIAhybn3m+MBGbq+hdb4IR5HnDFqfJBfZ7qGagr5NU366++5vTdxrcdnkQbwU8 b2QYZNMJQUvIMSs86mJ3MHXiOF5TRZUxcsdPSCTnlMM1o7aaqo7pvpJp5KwiGDIO 754Zolhp3S2oKboYvlcAw8P98i7IPAU8pKpbXor4pJuE8DH4RkJaoM2RCxjOA8tg == X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgeduledrvdekhedgudefucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfqfgfvpdfurfetoffkrfgpnffqhgen uceurghilhhouhhtmecufedttdenucesvcftvggtihhpihgvnhhtshculddquddttddmne cujfgurhepfffhvffukfhfgggtuggjsehttdertddttddvnecuhfhrohhmpefirhgvghcu mffjuceoghhrvghgsehkrhhorghhrdgtohhmqeenucggtffrrghtthgvrhhnpeevueehje fgfffgiedvudekvdektdelleelgefhleejieeugeegveeuuddukedvteenucfkphepkeef rdekiedrjeegrdeigeenucevlhhushhtvghrufhiiigvpedtnecurfgrrhgrmhepmhgrih hlfhhrohhmpehgrhgvgheskhhrohgrhhdrtghomh X-ME-Proxy: Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) by mail.messagingengine.com (Postfix) with ESMTPA; Thu, 27 May 2021 05:15:27 -0400 (EDT) Date: Thu, 27 May 2021 11:15:25 +0200 From: Greg KH To: Stephen Brennan Cc: stable@vger.kernel.org, Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Christoph Lameter , Mel Gorman , Andy Whitcroft , Aruna Ramakrishna , Khalid Aziz Subject: Re: [PATCH STABLE 4.4-5.3] mm, vmstat: drop zone->lock in /proc/pagetypeinfo Message-ID: References: <20210526174613.339990-1-stephen.s.brennan@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210526174613.339990-1-stephen.s.brennan@oracle.com> Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On Wed, May 26, 2021 at 10:46:13AM -0700, Stephen Brennan wrote: > Commit 93b3a674485f6a4b8ffff85d1682d5e8b7c51560 upstream > > Commit 93b3a674485f ("mm,vmstat: reduce zone->lock holding time by > /proc/pagetypeinfo") upstream caps the number of iterations over each > free_list at 100,000, and also drops the zone->lock in between each > migrate type. Capping the iteration count alters the file contents in > some cases, which means this approach may not be suitable for stable > backports. > > However, dropping zone->lock in between migrate types (and, as a result, > page orders) will not change the /proc/pagetypeinfo file contents. It > can significantly reduce the length of time spent with IRQs disabled, > which can prevent missed interrupts or soft lockups which we have > observed on systems with particularly large memory. > > Thus, this commit is a modified version of the upstream one which only > drops the lock in between migrate types. Now queued up, thanks. greg k-h