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=-6.0 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, NICE_REPLY_A,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 65103C07E95 for ; Sat, 10 Jul 2021 18:46:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3BE7961278 for ; Sat, 10 Jul 2021 18:46:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230025AbhGJSs7 (ORCPT ); Sat, 10 Jul 2021 14:48:59 -0400 Received: from mail.kernel.org ([198.145.29.99]:54956 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229599AbhGJSs7 (ORCPT ); Sat, 10 Jul 2021 14:48:59 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 8BD1D61279; Sat, 10 Jul 2021 18:46:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1625942773; bh=ZjhoTSsw3XgjxOm9U7sZ17N78UcAMbUtdDRXWELDlCA=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=ldgkQ1kfk2K3tXkAdSjnjdRjwMaXgO2kxxWxHtR0v5uEmqvU5I/mIUZVOxGtz3j1h Xh682rpOcp6cVumqy9dRRytEaTH+ZM6pVMIO9TEGB+vNnwa82vY7nLHijXLQCu9/2b EqLKz/ZLBbHR7ILZUN8u7orZUyaemLYKCSPze/iI= Date: Sat, 10 Jul 2021 11:46:13 -0700 From: Andrew Morton To: qiang.zhang@windriver.com Cc: 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: <20210710114613.0db3ac139a7b3102a6ca3ad4@linux-foundation.org> In-Reply-To: <20210710112929.232268-1-qiang.zhang@windriver.com> References: <20210710112929.232268-1-qiang.zhang@windriver.com> X-Mailer: Sylpheed 3.5.1 (GTK+ 2.24.32; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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?