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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id A71A0FED3E9 for ; Fri, 24 Apr 2026 15:39:49 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id DC5956B009F; Fri, 24 Apr 2026 11:39:48 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id D9CEC6B00A3; Fri, 24 Apr 2026 11:39:48 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id CB36E6B00A4; Fri, 24 Apr 2026 11:39:48 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id B9BD56B009F for ; Fri, 24 Apr 2026 11:39:48 -0400 (EDT) Received: from smtpin18.hostedemail.com (lb01b-stub [10.200.18.250]) by unirelay10.hostedemail.com (Postfix) with ESMTP id 6D2CBC0D68 for ; Fri, 24 Apr 2026 15:39:48 +0000 (UTC) X-FDA: 84693859656.18.DD4E07F Received: from out-185.mta0.migadu.com (out-185.mta0.migadu.com [91.218.175.185]) by imf02.hostedemail.com (Postfix) with ESMTP id A685480003 for ; Fri, 24 Apr 2026 15:39:46 +0000 (UTC) Authentication-Results: imf02.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=QouSNrZx; dmarc=pass (policy=none) header.from=linux.dev; spf=pass (imf02.hostedemail.com: domain of baoquan.he@linux.dev designates 91.218.175.185 as permitted sender) smtp.mailfrom=baoquan.he@linux.dev ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1777045186; a=rsa-sha256; cv=none; b=3qqeMP1GlUWECmqs5+cPlp9KwJ1ZAg9nLj1uUkheeg2aU7E//jmunknJ6kFwW8JQIrguze 1UOgvcb42irdRNzUvqty0a6KJxXPMhhpmJhI4g0dYXpSCfA3eCIu0EKAu5Jb1UJB+ZAlTM zxIDOPdC2pVfr2HEcYmi6aSWhXL7Afc= ARC-Authentication-Results: i=1; imf02.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=QouSNrZx; dmarc=pass (policy=none) header.from=linux.dev; spf=pass (imf02.hostedemail.com: domain of baoquan.he@linux.dev designates 91.218.175.185 as permitted sender) smtp.mailfrom=baoquan.he@linux.dev ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1777045186; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=IBUuy/iHD2cVL6NoMiF3zJR5EF0coOtwyWBZktOYkqI=; b=KwV2RlCzUqIyAkmTvROFdVaLKlByDArJt5LF0C+i8kQLOd2Qwv16FyBBPirsVTFyZIwgqU hTJQ7FSFR1fzDwszPZxFCzthlCF1FpbYkjw84W1lM7pigoSFdvKp287pjRn+keaI4yiy+R Wyzdtmewz/fDiNIqMmGGcEdxy1nA9Ps= Date: Fri, 24 Apr 2026 23:39:38 +0800 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1777045185; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=IBUuy/iHD2cVL6NoMiF3zJR5EF0coOtwyWBZktOYkqI=; b=QouSNrZxoV2DctjbcrIvV7lZUg3MbyYl79junU3vhVDRgKcq1JKGiApbyr8JxDAdn4OdtZ g/z5BCgG4jDGAxdoM/PDa0iU4wjdwx2kiH7U9CEg79rh/DNJjbHoi7c+iBQrs3QejhS3ii AXv7/LkneiYIzrIqJQcCJLHXhZX1iPU= X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Baoquan He To: kerayhuang Cc: kasong@tencent.com, bhe@redhat.com, linux-mm@kvack.org, kerayhuang , Hao Peng Subject: Re: [PATCH] mm/swap: Add cond_resched() in swap_reclaim_full_clusters to prevent softlockup Message-ID: References: <20260424123723.1820591-1-kerayhuang@tencent.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260424123723.1820591-1-kerayhuang@tencent.com> X-Migadu-Flow: FLOW_OUT X-Rspamd-Queue-Id: A685480003 X-Rspamd-Server: rspam12 X-Stat-Signature: oro5wbryscgxid9jpfm333x4m6fs1ter X-Rspam-User: X-HE-Tag: 1777045186-682412 X-HE-Meta: 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 oVTZHVOs aiUspmala5snR3tJec9QBjjWpNO7QzSE/CB/ZKK+HXEBaP0RI94dlMxZQuAvC0yssYfvH0q+iVl6Faq8jfjlZ8AwvA73uxGqLo0FRT9xKPBVgrI8UhvMwDKTdWKPhcgHVoIB2bLsz39YyT+H+qQybozBTNpcHHduIMOcCxXeE32kUbyB0M8gL5EY0MxUkZKoZ6oHkJfAAXNGHWuATvXIVzsfaMhzyez8nranHa639iQjL2IFdPvksPp9L7NiuV9btIbe4SpiDGQ+k6iVkcpHjeLNokH6fp5HaU6k324JqDIXxkyvKvDRTjElyZqM3nPP3ZuX6 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: Hi Keray, On 04/24/26 at 08:37pm, kerayhuang wrote: > Add periodic cond_resched() calls during large full_clusters > reclaim operations to prevent softlockup issues. > > Signed-off-by: kerayhuang > Reviewed-by: Kairui Song > Reviewed-by: Hao Peng > --- > mm/swapfile.c | 1 + > 1 file changed, 1 insertion(+) Thanks for the patch. The change looks good to me, however there are still small concerns. For patch log, it might be better to provide more details, e.g did you observe this issue in a product environment, or just a code exploring? If observed in a product environment, what does the backtrace look like when softlockup happened? > > diff --git a/mm/swapfile.c b/mm/swapfile.c > index 9174f1eeffb0..74a1e324449d 100644 > --- a/mm/swapfile.c > +++ b/mm/swapfile.c > @@ -1054,6 +1054,7 @@ static void swap_reclaim_full_clusters(struct swap_info_struct *si, bool force) > swap_cluster_unlock(ci); > if (to_scan <= 0) > break; > + cond_resched(); Besides, is it a little bit too aggressive to call cond_resched() for each cluster reclaiming compared with the old code? Do you consider to make it gentle, e.g calling cond_resched() every several clusters, 8, 16 or other number decided based on your testing performance statistics. Thanks Baoquan