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 9159DE77180 for ; Thu, 12 Dec 2024 14:05:58 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 111646B008C; Thu, 12 Dec 2024 09:05:58 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 0C0386B0092; Thu, 12 Dec 2024 09:05:58 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id EF1346B0093; Thu, 12 Dec 2024 09:05:57 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id D0D5E6B008C for ; Thu, 12 Dec 2024 09:05:57 -0500 (EST) Received: from smtpin22.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay04.hostedemail.com (Postfix) with ESMTP id 473C61A1D0F for ; Thu, 12 Dec 2024 14:05:57 +0000 (UTC) X-FDA: 82886480040.22.D31C149 Received: from shelob.surriel.com (shelob.surriel.com [96.67.55.147]) by imf30.hostedemail.com (Postfix) with ESMTP id 7816A80026 for ; Thu, 12 Dec 2024 14:05:07 +0000 (UTC) Authentication-Results: imf30.hostedemail.com; dkim=none; dmarc=none; spf=pass (imf30.hostedemail.com: domain of riel@shelob.surriel.com designates 96.67.55.147 as permitted sender) smtp.mailfrom=riel@shelob.surriel.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1734012332; a=rsa-sha256; cv=none; b=fdcO6NE/cPwGOD+uMGGOBe8qzu4BZRidIFS6vS7j/guiVQcAeq5EsOho7nfgmG4z2ap0LW FdLChtoDBz0HpICEBw/6H0uTROFE1SuElg6d2ZHKcHdf4vuo1s/7RJKgJ3VCKCF6EfeHIi mFDHQzMNORlyygTejrx0yBTHGrWkAKk= ARC-Authentication-Results: i=1; imf30.hostedemail.com; dkim=none; dmarc=none; spf=pass (imf30.hostedemail.com: domain of riel@shelob.surriel.com designates 96.67.55.147 as permitted sender) smtp.mailfrom=riel@shelob.surriel.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1734012332; h=from:from:sender: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:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=TcIZDm13wJtBL+TFVJnf0QGwPgEPd0n35Nv5UXAYJco=; b=ztLh09kirlfuNREhrzTr43+P1KZHwbH6CoPV+m83aT9syot1/PoNzy5tasSirWxKG8auXC FkFHbzJ6R5x/8v6kfz2c+QUuHnDeGjcldVbnPz5HE/BnDoJi1EvtKLSlzz4mn+zlpeuQuw u+0NAIt6RVyezjCGRcIyIHUghcbJlAE= Received: from fangorn.home.surriel.com ([10.0.13.7]) by shelob.surriel.com with esmtpsa (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.97.1) (envelope-from ) id 1tLjnA-000000005Ap-2F4L; Thu, 12 Dec 2024 09:03:48 -0500 Message-ID: <06afcaa995425c3c8b743485c6374ad92934f5de.camel@surriel.com> Subject: Re: [PATCH] memcg: allow exiting tasks to write back data to swap From: Rik van Riel To: Balbir Singh , Johannes Weiner Cc: Michal Hocko , Roman Gushchin , Shakeel Butt , Muchun Song , Andrew Morton , cgroups@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, kernel-team@meta.com, Nhat Pham , Yosry Ahmed Date: Thu, 12 Dec 2024 09:03:48 -0500 In-Reply-To: <1974c064-4c17-403c-a0a0-a799cbdae2f9@nvidia.com> References: <20241211105336.380cb545@fangorn> <766a28a1-c82b-46fd-b3b0-fe3b6024f462@nvidia.com> <1764e2fc8cff5b07aa9df1ae90a13986a3949250.camel@surriel.com> <1974c064-4c17-403c-a0a0-a799cbdae2f9@nvidia.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.54.1 (3.54.1-1.fc41) MIME-Version: 1.0 X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 7816A80026 X-Stat-Signature: p1ir4sjo31fdsydzdqr5wdzuoxmxdrjy X-Rspam-User: X-HE-Tag: 1734012307-609483 X-HE-Meta: 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 rHNahgin wxQO9DLKiCtpCEh3NApy6ijH0dZL7Gp4NF48nvEb7GizTF2isx9oQLX/WFfKWv9q15tSMzjKufQeCWrbOKwAJcNlqFCOMhKEfvd4TequNuazjrZsKjHXkz0RRXWwepz5H6iemhuPJd3ucHntHL7WpGBmRbU8k6Yh7D0yHCs0W7sUCNZk9fQqKFKhe/u0NLxO8Vx1AJXzN4kAggru8rQsZm6cyyyaQCA3WkzRmpUFku1HA0Rzu+CdcQnou+K5lk+DRUMNQACCKPuPUnO2vDYWRlKAMTiyxml5c9yW2 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: List-Subscribe: List-Unsubscribe: On Thu, 2024-12-12 at 14:25 +1100, Balbir Singh wrote: >=20 > I was asking about this change (this patch), I know that the return > true will help avoid the PAGE_ACTIVATE path, but I am not sure why > this function will return false if CONFIG_ZSWAP is enabled (unless > zswap_writeback is turned off in one of the groups) >=20 Some workloads are fine with incurring the latency from zswap, but do not want the latency of actual block device backed swap. Having zswap enabled, with writeback disabled, has been beneficial to a number of workloads. --=20 All Rights Reversed.