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 94668C433F5 for ; Thu, 21 Apr 2022 12:41:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1382562AbiDUMnx (ORCPT ); Thu, 21 Apr 2022 08:43:53 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45330 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231220AbiDUMnv (ORCPT ); Thu, 21 Apr 2022 08:43:51 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 964E72ED53 for ; Thu, 21 Apr 2022 05:41:01 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 53023B8245D for ; Thu, 21 Apr 2022 12:41:00 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id EBAEDC385A5; Thu, 21 Apr 2022 12:40:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1650544859; bh=xkTQja7+LerFcAfv+h4EcoXiBpBwuV21oqU53tUIV8Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=rD1FimIorOOdZCo7roNu4NSIBAY7tJROF6cmsXeuuo/xuSZjMgDzb3XEpYTZjVr+R WIP6eORivB4ZFMLtKTBQhU4evtpXpaxv9GGVEhE/aMH70fo5wszHcDyzaK5RfrZ+/a +S3MJASoo5gDa9Gx+i4AWRPWyzw54uUlzX1+YMB7TednGk2Tr13VwgvYm7PXYLHswI j2q2MhJYlctrmsZiZCsk+dTe1fJrivSYt75Izj7bPUBOJY/sgIey0y3smSzGdfCpNi QNCvkU9z8tl0GQOvi+PItuQ3pMSFaHxxbyb+W0xhw0XgKCcxhE4hEJFrA1lI+zm7yS Kt/K7Ku7lLp+Q== From: SeongJae Park To: Hailong Tu Cc: akpm@linux-foundation.org, sj@kernel.org, torvalds@linux-foundation.org, gregkh@google.com, surenb@google.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, tuhailong@oppo.com, lichunpeng@oppo.com, aaron.qiu@oppo.com, fanguoze@oppo.com, wangdesuo@oppo.com, lizhihua@oppo.com Subject: Re: [PATCH V4] mm/damon/reclaim: Fix the timer always stays active Date: Thu, 21 Apr 2022 12:40:55 +0000 Message-Id: <20220421124055.493710-1-sj@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220421100523.689294-1-tuhailong@gmail.com> References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Hailong, On Thu, 21 Apr 2022 18:05:24 +0800 Hailong Tu wrote: > The timer stays active even if the reclaim mechanism is never enabled. > It is unnecessary overhead can be completely avoided by using module_param_cb() for enabled flag. As commented to the previous version[1], let's wrap the line at 75 columns. checkpatch.pl is also complaining. [1] https://lore.kernel.org/linux-mm/20220421084806.72553-1-sj@kernel.org/ > > Signed-off-by: Hailong Tu > --- > mm/damon/reclaim.c | 26 ++++++++++++++++++++++++-- > 1 file changed, 24 insertions(+), 2 deletions(-) > > diff --git a/mm/damon/reclaim.c b/mm/damon/reclaim.c > index e34c4d0c4d93..e573e3f50064 100644 > --- a/mm/damon/reclaim.c > +++ b/mm/damon/reclaim.c > @@ -28,7 +28,6 @@ > * this. > */ > static bool enabled __read_mostly; > -module_param(enabled, bool, 0600); > > /* > * Time threshold for cold memory regions identification in microseconds. > @@ -358,11 +357,34 @@ static void damon_reclaim_timer_fn(struct work_struct *work) > enabled = last_enabled; > } > > - schedule_delayed_work(&damon_reclaim_timer, > + if (enabled) > + schedule_delayed_work(&damon_reclaim_timer, > msecs_to_jiffies(ENABLE_CHECK_INTERVAL_MS)); > } > static DECLARE_DELAYED_WORK(damon_reclaim_timer, damon_reclaim_timer_fn); > > +static int enabled_store(const char *val, > + const struct kernel_param *kp) > +{ > + int rc = param_set_bool(val, kp); > + > + if (rc < 0) > + return rc; > + > + if (enabled) > + schedule_delayed_work(&damon_reclaim_timer, 0); > + > + return 0; > +} > + > +static const struct kernel_param_ops enabled_param_ops = { > + .set = enabled_store, > + .get = param_get_bool, > +}; > + > +module_param_cb(enabled, &enabled_param_ops, &enabled, 0600); > +MODULE_PARM_DESC(enabled, "Enable or disable DAMON_RECLAIM (default: disabled)"); I'd prefer 80 columns limit. Could you please put the string in the next line, like below? MODULE_PARM_DESC(enabled, "Enable or disable DAMON_RECLAIM (default: disabled)"); Thanks, SJ > + > static int damon_reclaim_after_aggregation(struct damon_ctx *c) > { > struct damos *s; > -- > 2.25.1 >