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=-3.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED 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 2E2A8C07E95 for ; Sat, 10 Jul 2021 21:10:27 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 9EA6D6135E for ; Sat, 10 Jul 2021 21:10:26 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9EA6D6135E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 410E96B0074; Sat, 10 Jul 2021 17:10:26 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 3E83D6B0078; Sat, 10 Jul 2021 17:10:26 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 2B0416B007B; Sat, 10 Jul 2021 17:10:26 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0036.hostedemail.com [216.40.44.36]) by kanga.kvack.org (Postfix) with ESMTP id 09BDB6B0074 for ; Sat, 10 Jul 2021 17:10:26 -0400 (EDT) Received: from smtpin38.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 2D4C78248D52 for ; Sat, 10 Jul 2021 21:10:25 +0000 (UTC) X-FDA: 78347921610.38.CF92BE7 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf26.hostedemail.com (Postfix) with ESMTP id 756B920019CD for ; Sat, 10 Jul 2021 21:10:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=3Fv3JaRsdV1s9RLb16qwGkvG9CqOP8qJx48U5nNcWB4=; b=Yp8zWtcy26W2BtPEMT2CjH4Gke Xn0rxqYx1pvRTOyswBT7QbQVhezMkXCivxY/pAHYdNfrYrXGkhi1bX6tAENIzIYRHlyqu/BhHNQdZ tDNNw6xlT1+HwBxBXpOclx21UHLponACB9rhAXi8Ed7DYAk/f/nlSrMW/VG4E7IBkwo6XFzPR15o8 ueSy/D43aRuxoGnBRt9q8nx6kGuIVvUq2lY4l42PlEIZgfQuWTSa/RwP6oEO57EeikrTk39qtHCrT Kndgc+qQP15tp+fsINoHMvLfqHkMJTO7u2bWVNeTeTgdUNjMa0xR1SdgHvYAax+G2+P5j/GL0NRFN 4itYNJYA==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1m2KEd-00FlRk-Rz; Sat, 10 Jul 2021 21:10:06 +0000 Date: Sat, 10 Jul 2021 22:10:03 +0100 From: Matthew Wilcox To: Andrew Morton Cc: qiang.zhang@windriver.com, mgorman@techsingularity.net, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] mm/page_alloc: avoid hard lockups in __alloc_pages_bulk() Message-ID: References: <20210710112929.232268-1-qiang.zhang@windriver.com> <20210710114613.0db3ac139a7b3102a6ca3ad4@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210710114613.0db3ac139a7b3102a6ca3ad4@linux-foundation.org> Authentication-Results: imf26.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=Yp8zWtcy; spf=none (imf26.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org; dmarc=none X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: 756B920019CD X-Stat-Signature: ufzoeghcic47d5nenup9n1ejxha64dur X-HE-Tag: 1625951424-46827 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 Sat, Jul 10, 2021 at 11:46:13AM -0700, Andrew Morton wrote: > On Sat, 10 Jul 2021 19:29:29 +0800 qiang.zhang@windriver.com wrote: > > > From: Zqiang > > > > The __alloc_pages_bulk() mainly used for batch allocation of > > order-0 pages, in the case of holding pagesets.lock, if too > > many pages are required, maybe trigger hard lockup watchdog. > > Ouch. Has this been observed in testing? If so, can you please share > the kernel debug output from that event? This should be fixed in the caller by asking for fewer pages. The NFS and vmalloc cases have already been fixed for this.