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]) by smtp.lore.kernel.org (Postfix) with ESMTP id 837C3C6FA82 for ; Tue, 13 Sep 2022 15:11:21 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id B8CFA6B0071; Tue, 13 Sep 2022 11:11:20 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id B15A66B0072; Tue, 13 Sep 2022 11:11:20 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 992668D0001; Tue, 13 Sep 2022 11:11:20 -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 8590D6B0071 for ; Tue, 13 Sep 2022 11:11:20 -0400 (EDT) Received: from smtpin01.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id 4FFF31C61DC for ; Tue, 13 Sep 2022 15:11:20 +0000 (UTC) X-FDA: 79907400720.01.50E3D14 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by imf28.hostedemail.com (Postfix) with ESMTP id DA484C00C1 for ; Tue, 13 Sep 2022 15:11:19 +0000 (UTC) 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 dfw.source.kernel.org (Postfix) with ESMTPS id 7D003614C2; Tue, 13 Sep 2022 15:11:17 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id DEE19C433C1; Tue, 13 Sep 2022 15:11:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1663081876; bh=C2SleSiuBkOWC306gvMd63ndpm5F32RdHPWF/1NZ+Mo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=d6EvO1tbHXy5BnLWx+aINqFnlkt2g4z3xcHVU2o/GN+MBsp/HbSX3LY2E/6UIeodI 9XBVm2KxKb49tlqgxUTC//o0tZQ2uovfGUcC02jNZoRESrLW9q7O1mWsVTy+2aT67x f8BwGM15zXQAkeoO26xkITIkD7CxSpcJw/K0Ukg/EN2H8yIfPjlcZ5mzs9/xj861Zp PcK8a60fm9yHTfIAbT4PfeV3xY1ERsqdoCsfoMxvUjOAaya5yX3mAyn0V+5vWy94n9 89XxK0MedRYIjfq59D0ICSFrBlIQUUv/XQeOPhwh0zfqr6p38TXNgwiyDqwVUC46UY P9JAbfa66K85g== From: SeongJae Park To: xiakaixu1987@gmail.com Cc: sj@kernel.org, akpm@linux-foundation.org, damon@lists.linux.dev, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Kaixu Xia Subject: Re: [PATCH 4/4] mm/damon/vaddr: indicate the target is invalid when 'nr_regions' is zero Date: Tue, 13 Sep 2022 15:11:14 +0000 Message-Id: <20220913151114.103184-1-sj@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <1663060287-30201-5-git-send-email-kaixuxia@tencent.com> References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1663081879; a=rsa-sha256; cv=none; b=UeugRH0bqZLP9KNF5x0KwzZOu/iuQ/RWreTjWctfojzbZSCK0pYrd49IbnRQp7TgyFuJfy OZF8DJBxVNZbYvd5wgEKkGVmQI5GUk9zi2zFB17Mop4RpIyIm1DEsR6Y2aQdITMHvDTK9q Nv5o2ghKSOakxXdaQ0XxDhonw20HiJY= ARC-Authentication-Results: i=1; imf28.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=d6EvO1tb; dmarc=pass (policy=none) header.from=kernel.org; spf=pass (imf28.hostedemail.com: domain of sj@kernel.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=sj@kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1663081879; 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-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=4h/vtp4Q2c1nj2nyly9Fzd82UmCGNjtkCLgBNKAYO2o=; b=cKkQ40aLVchHgT5tZJPblgiThFC8dF5c590MX5w88AaBreWOtwDec5uOOBCwiJu6TzIC05 7I4vclOZL2JaBLdhtCV1KML9bbE2Q42hKH7quKjDIzd5uaOunDvAEVALiTapp0G2pasdCC cdYGatmiLiIOpCjub5xp5u6P/LK1aGo= Authentication-Results: imf28.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=d6EvO1tb; dmarc=pass (policy=none) header.from=kernel.org; spf=pass (imf28.hostedemail.com: domain of sj@kernel.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=sj@kernel.org X-Rspam-User: X-Rspamd-Server: rspam06 X-Stat-Signature: d1r7zjm4j8yjarsyhdspquqssqa6p18k X-Rspamd-Queue-Id: DA484C00C1 X-HE-Tag: 1663081879-387832 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Tue, 13 Sep 2022 17:11:27 +0800 xiakaixu1987@gmail.com wrote: > From: Kaixu Xia > > When 'init()' and 'update()' DAMON operations failed and the number > of the damon_target regions is zero, Well, I think that could be a temporal failure. In the case, later call of 'update()' could success? Thanks, SJ > the kdamond would do nothing > to this monitoring target in this case. It makes no sense to run > kdamond when all of monitoring targets have no regions. So add the > judgement in 'target_valid()' operation to indicate the target is > invalid when 'nr_regions' is zero. > > Signed-off-by: Kaixu Xia > --- > mm/damon/vaddr.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/mm/damon/vaddr.c b/mm/damon/vaddr.c > index 39ea48d9cc15..65ff98d49ec0 100644 > --- a/mm/damon/vaddr.c > +++ b/mm/damon/vaddr.c > @@ -598,6 +598,9 @@ static bool damon_va_target_valid(void *target) > struct damon_target *t = target; > struct task_struct *task; > > + if (!damon_nr_regions(t)) > + return false; > + > task = damon_get_task_struct(t); > if (task) { > put_task_struct(task); > -- > 2.27.0