From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.7]) (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 ACC1D8F55 for ; Wed, 7 Feb 2024 01:08:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.7 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707268084; cv=none; b=VSnsva3dj1gT1ajBAKRHzhYdrOMazJZuoq6FkMTLaRIg+r9Om1JPJ4LuTlE+Bh91dXPoq3tYbr2pa2zugIUHvKX4rzLibpHXgSZsq0424GqaiuSEKl+4NIIOrX2NLtsuE92GKFinT/GDf14/EE5ndJb0B8lNlrVAyvwhfBguaYc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707268084; c=relaxed/simple; bh=YWoqPUFfMGS47WFb4mE5+cl1K2/d2tJFTG4u0nDPs6Q=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=b0ezG1wkmYSHDkGtWN1HFPxgJN3LF090HJr514uAuF86TX9m1l3x4Qqa2EWFGva2s2720PBygwEcMHfaOIvzaJgq9/wnHH7z4EK4vxB7XVUT0xvnmNtEf4iRFV3eJXaXxFICLNmAP6ivxTNnw7XpT8jXosB1lmFc5RZQaqNCAa8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=none smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=ZLu4yKjX; arc=none smtp.client-ip=192.198.163.7 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="ZLu4yKjX" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1707268081; x=1738804081; h=message-id:subject:from:to:cc:date:in-reply-to: references:content-transfer-encoding:mime-version; bh=YWoqPUFfMGS47WFb4mE5+cl1K2/d2tJFTG4u0nDPs6Q=; b=ZLu4yKjX/hUYIj8V3mtDyYSM25s0Jl2r3BHa3XEyE/aYphjXjafVxsBc jTktXKxwoqu2t1e8uBu83CaiHTMdpa7RyRhb2h26O92JbWFV8E41wN1s+ e/J2b/XNtXSPl1hTWp/Q2P+5YPzPY/OTvjAyOsCKTRPM4JAB9z2ZK6Mo5 agVGlzLxZtZyhAchQK6n7rfKUA71YAYJCYviIlKZLf2sisxJZ4IYfTJKG xeTCODAxlKbVOS8fTA2ArFWP65vlVdx8kdZgnFohE9ZT02hhs0wTYr/ky fGzCMwSzRyKoQP0O6lgyOr70BSzUNNlPnrE9Dji+7zgT014+9mNaL5HQp A==; X-IronPort-AV: E=McAfee;i="6600,9927,10976"; a="26326489" X-IronPort-AV: E=Sophos;i="6.05,248,1701158400"; d="scan'208";a="26326489" Received: from fmviesa001.fm.intel.com ([10.60.135.141]) by fmvoesa101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 06 Feb 2024 17:08:00 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.05,248,1701158400"; d="scan'208";a="32260071" Received: from rmahambr-mobl.amr.corp.intel.com (HELO [10.209.58.248]) ([10.209.58.248]) by smtpauth.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 06 Feb 2024 17:08:00 -0800 Message-ID: Subject: Re: [PATCH v2] mm: swap: async free swap slot cache entries From: Tim Chen To: Chris Li Cc: "Huang, Ying" , Andrew Morton , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Wei =?UTF-8?Q?Xu=EF=BF=BC?= , Yu =?UTF-8?Q?Zhao=EF=BF=BC?= , Greg Thelen , Chun-Tse Shao , Suren =?UTF-8?Q?Baghdasaryan=EF=BF=BC?= , Yosry =?UTF-8?Q?Ahmed=EF=BF=BC?= , Brain Geffon , Minchan Kim , Michal Hocko , Mel Gorman , Nhat Pham , Johannes Weiner , Kairui Song , Zhongkun He , Kemeng Shi , Barry Song Date: Tue, 06 Feb 2024 17:08:00 -0800 In-Reply-To: References: <20240131-async-free-v2-1-525f03e07184@kernel.org> <87sf2ceoks.fsf@yhuang6-desk2.ccr.corp.intel.com> <7f19b4d69ff20efe8260a174c7866b4819532b1f.camel@linux.intel.com> <1fa1da19b0b929efec46bd02a6fc358fef1b9c42.camel@linux.intel.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.44.4 (3.44.4-2.fc36) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 On Mon, 2024-02-05 at 11:10 -0800, Chris Li wrote: >=20 >=20 > In our system, a really heavy swap load is rare and it means something > is already wrong. At that point the app's SLO is likely at risk, > regardless of long tail swap latency. It is already too late to > address it at the swap fault end. We need to address the source of the > problem which is swapping out too much. >=20 >=20 Could some usage scenarios put more pressure on swap than your usage scenario? Say system with limited RAM and rely on zswap? Tim