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 A8B61C433EF for ; Tue, 8 Mar 2022 16:05:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1348057AbiCHQGo (ORCPT ); Tue, 8 Mar 2022 11:06:44 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48554 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234365AbiCHQGn (ORCPT ); Tue, 8 Mar 2022 11:06:43 -0500 Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.220.28]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8AEAB5004F for ; Tue, 8 Mar 2022 08:05:46 -0800 (PST) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id 3D561210ED; Tue, 8 Mar 2022 16:05:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1646755545; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=0lx7YZSPD/NWaBAYAIlDv0jZWjoT8LAg8HptCJpJ5yU=; b=EFBWMFI2Rxsm8YrOdrTofZYz3kbV2C9ZaQV9WLdMaepQJGkahneDLnuGjvsjEHf07rA/hX idDOvjF25TjPm0UhnRzsPk2EM902Fe307zW/fqaLG7PMnOCdsu481MaHVTg2PRJedCfJ70 xuPLzQxJMi3Efrtr8YFGLW5Nd8vKFlU= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1646755545; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=0lx7YZSPD/NWaBAYAIlDv0jZWjoT8LAg8HptCJpJ5yU=; b=t19XOfxAmOcK+iiTB+A3WjupVbi99h23HgjvKnRFQGRPCPIamvh20JWzx2DtCGhh43nVGn u34yE96BIhEtUcBg== Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id 1D29713CCE; Tue, 8 Mar 2022 16:05:45 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id seaVBtl+J2JqaAAAMHmgww (envelope-from ); Tue, 08 Mar 2022 16:05:45 +0000 Message-ID: Date: Tue, 8 Mar 2022 17:05:44 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.6.1 Subject: Re: [PATCH 1/1] mm/page_alloc: add scheduling point to free_unref_page_list Content-Language: en-US To: wangjianxing , Andrew Morton Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Michal Hocko , Mel Gorman References: <20220302013825.2290315-1-wangjianxing@loongson.cn> From: Vlastimil Babka In-Reply-To: <20220302013825.2290315-1-wangjianxing@loongson.cn> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 3/2/22 02:38, wangjianxing wrote: > free a large list of pages maybe cause rcu_sched starved on > non-preemptible kernels > > rcu: rcu_sched kthread starved for 5359 jiffies! g454793 f0x0 > RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=19 > [...] > Call Trace: > free_unref_page_list+0x19c/0x270 > release_pages+0x3cc/0x498 > tlb_flush_mmu_free+0x44/0x70 > zap_pte_range+0x450/0x738 > unmap_page_range+0x108/0x240 > unmap_vmas+0x74/0xf0 > unmap_region+0xb0/0x120 > do_munmap+0x264/0x438 > vm_munmap+0x58/0xa0 > sys_munmap+0x10/0x20 > syscall_common+0x24/0x38 > > Signed-off-by: wangjianxing Acked-by: Vlastimil Babka > --- > mm/page_alloc.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index 3589febc6..1b96421c8 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -3479,6 +3479,9 @@ void free_unref_page_list(struct list_head *list) > */ > if (++batch_count == SWAP_CLUSTER_MAX) { > local_unlock_irqrestore(&pagesets.lock, flags); > + > + cond_resched(); > + > batch_count = 0; > local_lock_irqsave(&pagesets.lock, flags); > }