From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail115-95.sinamail.sina.com.cn (mail115-95.sinamail.sina.com.cn [218.30.115.95]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3B6E91CBE8D for ; Fri, 6 Sep 2024 11:39:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=218.30.115.95 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725622799; cv=none; b=IjaitkwTbkVBpzieAQGazZbv9NZijo+Y3zyuuBRQu7Oplev6XYTofdJAYiSmqRMU05e0zkKGEsUW2ZgDpnbJLIXpoy9FVJa4uRGvkSmtNMgld3vwCOAqKPivl+lWHpeTMrcA2YNcqvAGJBRdtPbNrLjwwUSbc4/KfKCDAxrK73k= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725622799; c=relaxed/simple; bh=b6EX1KbjDsbwjjyz8D2+nppHJaklNhNxOJ4QiOIDYDU=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=HXdHylLH/Lm55jzytpbbL8S6VAF5WR2PSN/LCB+oOBeLctsZK0IG6S5sLHfrmXV5hrlekhip+dEos/T3OSZgTEf9enzPMzm9VwIVqecJ0AODd+su4VVGCFpDA80SvaparNuyNnvTiG+X/RIqn0CPQ/Qt7RU3ApQyyMrP7U4a+a0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=sina.com; spf=pass smtp.mailfrom=sina.com; arc=none smtp.client-ip=218.30.115.95 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=sina.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=sina.com X-SMAIL-HELO: localhost.localdomain Received: from unknown (HELO localhost.localdomain)([116.24.11.67]) by sina.com (10.185.250.23) with ESMTP id 66DAE1BC000070D4; Fri, 6 Sep 2024 19:04:31 +0800 (CST) X-Sender: hdanton@sina.com X-Auth-ID: hdanton@sina.com Authentication-Results: sina.com; spf=none smtp.mailfrom=hdanton@sina.com; dkim=none header.i=none; dmarc=none action=none header.from=hdanton@sina.com X-SMAIL-MID: 1108818913234 X-SMAIL-UIID: 851DCCE2AE5142398F3D38AD0207E054-20240906-190431-1 From: Hillf Danton To: Davidlohr Bueso Cc: yosryahmed@google.com, mhocko@kernel.org, Andrew Morton , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH -next] mm: introduce per-node proactive reclaim interface Date: Fri, 6 Sep 2024 19:04:19 +0800 Message-Id: <20240906110419.2079-1-hdanton@sina.com> In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit On Thu, 5 Sep 2024 16:29:41 -0700 Davidlohr Bueso > On Fri, 06 Sep 2024, Hillf Danton wrote:\n > >The proactive reclaim on the cmdline looks like waste of cpu cycles before > >the cases where kswapd fails to work are spotted. It is not correct to add > >it because you can type the code. > > Are you against proactive reclaim altogether (ie: memcg) or this patch in > particular, which extends its availability? > The against makes no sense to me because I know your patch is never able to escape standing ovation. > The benefits of proactive reclaim are well documented, and the community has > been overall favorable towards it. This operation is not meant to be generally > used, but there are real latency benefits to be had which are completely > unrelated to watermarks. Similarly, we have 'compact' as an alternative to > kcompactd (which was once upon a time part of kswapd). > Because kswapd is responsible for watermark instead of high order pages, compact does not justify proactive reclaim from the begining.