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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E8F99C54EE9 for ; Tue, 13 Sep 2022 07:03:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230315AbiIMHDA (ORCPT ); Tue, 13 Sep 2022 03:03:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60208 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229821AbiIMHC6 (ORCPT ); Tue, 13 Sep 2022 03:02:58 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 383DA14D14 for ; Tue, 13 Sep 2022 00:02:56 -0700 (PDT) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id DF4A7106F; Tue, 13 Sep 2022 00:03:02 -0700 (PDT) Received: from [10.162.42.9] (unknown [10.162.42.9]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 123293F73B; Tue, 13 Sep 2022 00:03:21 -0700 (PDT) Message-ID: Date: Tue, 13 Sep 2022 12:32:50 +0530 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.11.0 Subject: Re: [PATCH 01/16] mm/page_alloc: ensure kswapd doesn't accidentally go to sleep Content-Language: en-US To: Miaohe Lin , akpm@linux-foundation.org Cc: david@redhat.com, osalvador@suse.de, linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <20220909092451.24883-1-linmiaohe@huawei.com> <20220909092451.24883-2-linmiaohe@huawei.com> From: Anshuman Khandual In-Reply-To: <20220909092451.24883-2-linmiaohe@huawei.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 9/9/22 14:54, Miaohe Lin wrote: > If ALLOC_KSWAPD is set, wake_all_kswapds() will be called to ensure > kswapd doesn't accidentally go to sleep. But when reserve_flags is > set, alloc_flags will be overwritten and ALLOC_KSWAPD is thus lost. > Preserve the ALLOC_KSWAPD flag in alloc_flags to ensure kswapd won't > go to sleep accidentally. Currently wake_all_kswapds() gets skipped subsequently if ALLOC_KSWAPD is lost, but this only happens when the 'retry:' loops is taken ? > > Fixes: 0a79cdad5eb2 ("mm: use alloc_flags to record if kswapd can wake") > Signed-off-by: Miaohe Lin > --- > mm/page_alloc.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index ba5c9402a5cb..4b97a03fa2dd 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -5147,7 +5147,8 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order, > > reserve_flags = __gfp_pfmemalloc_flags(gfp_mask); > if (reserve_flags) > - alloc_flags = gfp_to_alloc_flags_cma(gfp_mask, reserve_flags); > + alloc_flags = gfp_to_alloc_flags_cma(gfp_mask, reserve_flags) | > + (alloc_flags & ALLOC_KSWAPD); > > /* > * Reset the nodemask and zonelist iterators if memory policies can be