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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 EF107C433E0 for ; Fri, 19 Jun 2020 15:12:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D0F8121582 for ; Fri, 19 Jun 2020 15:12:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592579539; bh=cqoKE8jnzFDqMW4LqryMW7u3xX8ID9YYt5ofJtGRiKg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=wrvXfqNCTjccwBtvBpnVQq4ZobRN+V2Ua9xDBoWWWsE7lEPuhkGzzl9opKLM0pKrT MwkoIMXSAd5e21Wzt3mw70pbDZidx+ktCVw2X4RLVD8efkDmR4C3Lv6Jf7TGgQLINB dbHwLg+/pG8sr47vMCkLp0nGrHdPMRmRQ6ygA3r8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391876AbgFSPMT (ORCPT ); Fri, 19 Jun 2020 11:12:19 -0400 Received: from mail.kernel.org ([198.145.29.99]:42640 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2392145AbgFSPMO (ORCPT ); Fri, 19 Jun 2020 11:12:14 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (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 F18C32158C; Fri, 19 Jun 2020 15:12:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592579533; bh=cqoKE8jnzFDqMW4LqryMW7u3xX8ID9YYt5ofJtGRiKg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Pk328ZMv7Zd0rye65Qy0QOrUveiOcmJqcgjkh3lFw9bi6E/wufTHTi6J5hZ1aXmpb DQTfYxttCmcTqtKByU6hqkulwAfceDu31Mg7h6XhchcARJKe9vpumyz+OZFbkQ8sPP 2GWU5VUmmFi3OMCsRBojm6/B5npNHXdqiiKamOqY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Daniel Jordan , Pavel Tatashin , Andrew Morton , David Hildenbrand , Michal Hocko , Vlastimil Babka , Dan Williams , Shile Zhang , Kirill Tkhai , James Morris , Sasha Levin , Yiqian Wei , Linus Torvalds Subject: [PATCH 5.4 172/261] mm/pagealloc.c: call touch_nmi_watchdog() on max order boundaries in deferred init Date: Fri, 19 Jun 2020 16:33:03 +0200 Message-Id: <20200619141658.152908731@linuxfoundation.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200619141649.878808811@linuxfoundation.org> References: <20200619141649.878808811@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Daniel Jordan commit 117003c32771df617acf66e140fbdbdeb0ac71f5 upstream. Patch series "initialize deferred pages with interrupts enabled", v4. Keep interrupts enabled during deferred page initialization in order to make code more modular and allow jiffies to update. Original approach, and discussion can be found here: http://lkml.kernel.org/r/20200311123848.118638-1-shile.zhang@linux.alibaba.com This patch (of 3): deferred_init_memmap() disables interrupts the entire time, so it calls touch_nmi_watchdog() periodically to avoid soft lockup splats. Soon it will run with interrupts enabled, at which point cond_resched() should be used instead. deferred_grow_zone() makes the same watchdog calls through code shared with deferred init but will continue to run with interrupts disabled, so it can't call cond_resched(). Pull the watchdog calls up to these two places to allow the first to be changed later, independently of the second. The frequency reduces from twice per pageblock (init and free) to once per max order block. Fixes: 3a2d7fa8a3d5 ("mm: disable interrupts while initializing deferred pages") Signed-off-by: Daniel Jordan Signed-off-by: Pavel Tatashin Signed-off-by: Andrew Morton Reviewed-by: David Hildenbrand Acked-by: Michal Hocko Acked-by: Vlastimil Babka Cc: Dan Williams Cc: Shile Zhang Cc: Kirill Tkhai Cc: James Morris Cc: Sasha Levin Cc: Yiqian Wei Cc: [4.17+] Link: http://lkml.kernel.org/r/20200403140952.17177-2-pasha.tatashin@soleen.com Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- mm/page_alloc.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1640,7 +1640,6 @@ static void __init deferred_free_pages(u } else if (!(pfn & nr_pgmask)) { deferred_free_range(pfn - nr_free, nr_free); nr_free = 1; - touch_nmi_watchdog(); } else { nr_free++; } @@ -1670,7 +1669,6 @@ static unsigned long __init deferred_in continue; } else if (!page || !(pfn & nr_pgmask)) { page = pfn_to_page(pfn); - touch_nmi_watchdog(); } else { page++; } @@ -1817,8 +1815,10 @@ static int __init deferred_init_memmap(v * that we can avoid introducing any issues with the buddy * allocator. */ - while (spfn < epfn) + while (spfn < epfn) { nr_pages += deferred_init_maxorder(&i, zone, &spfn, &epfn); + touch_nmi_watchdog(); + } zone_empty: /* Sanity check that the next zone really is unpopulated */ WARN_ON(++zid < MAX_NR_ZONES && populated_zone(++zone)); @@ -1889,6 +1889,7 @@ deferred_grow_zone(struct zone *zone, un first_deferred_pfn = spfn; nr_pages += deferred_init_maxorder(&i, zone, &spfn, &epfn); + touch_nmi_watchdog(); /* We should only stop along section boundaries */ if ((first_deferred_pfn ^ spfn) < PAGES_PER_SECTION)