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 1A301C6FD1F for ; Fri, 29 Mar 2024 17:45:02 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 7C6BF6B008A; Fri, 29 Mar 2024 13:45:02 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 74F3C6B008C; Fri, 29 Mar 2024 13:45:02 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 5C8DC6B0092; Fri, 29 Mar 2024 13:45:02 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id 3CB6B6B008A for ; Fri, 29 Mar 2024 13:45:02 -0400 (EDT) Received: from smtpin05.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id 08B6040F83 for ; Fri, 29 Mar 2024 17:45:02 +0000 (UTC) X-FDA: 81950802444.05.83FF297 Received: from mail-ot1-f52.google.com (mail-ot1-f52.google.com [209.85.210.52]) by imf20.hostedemail.com (Postfix) with ESMTP id EDB351C0016 for ; Fri, 29 Mar 2024 17:44:59 +0000 (UTC) Authentication-Results: imf20.hostedemail.com; dkim=pass header.d=cmpxchg-org.20230601.gappssmtp.com header.s=20230601 header.b=dczKONTB; spf=pass (imf20.hostedemail.com: domain of hannes@cmpxchg.org designates 209.85.210.52 as permitted sender) smtp.mailfrom=hannes@cmpxchg.org; dmarc=pass (policy=none) header.from=cmpxchg.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1711734300; 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-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=7WPAvDk3zSOm8wRKlGIEh/4VbBWjZSS4f1jGmiLObHs=; b=g4EDVT0RP/fKIGerN2oHPW3cB9WNw6QR9/nWQReWSwfKh/bRn83fdTpUaBj02zFtrrWd+P BYn/rLicT5vvNtG+rVBf+2Mf3rQCxji9XOrsF2S+UTciX/mB8NP1aEREGeoXWvtkR6CEhp 9tqQX2ngB64auuTr/hZyykRWEjB0n84= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1711734300; a=rsa-sha256; cv=none; b=tuWjIWE26W21nn1woV6x/TZxIDpvG/xVbMQwZaAkjHEYLEd0SgJME+xiC+sPALzTXkqizY 7DiHP/YsaWIA8Pg2gECAqZC+RFUj/Z+AFxUh48X7chRWJF3yG3ydWEfGKECPv1D9+5Vx5B pXzanXtnfvNYgxdC/0DsoHwKkv3gy5w= ARC-Authentication-Results: i=1; imf20.hostedemail.com; dkim=pass header.d=cmpxchg-org.20230601.gappssmtp.com header.s=20230601 header.b=dczKONTB; spf=pass (imf20.hostedemail.com: domain of hannes@cmpxchg.org designates 209.85.210.52 as permitted sender) smtp.mailfrom=hannes@cmpxchg.org; dmarc=pass (policy=none) header.from=cmpxchg.org Received: by mail-ot1-f52.google.com with SMTP id 46e09a7af769-6e6db4dfd7aso1431118a34.2 for ; Fri, 29 Mar 2024 10:44:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cmpxchg-org.20230601.gappssmtp.com; s=20230601; t=1711734299; x=1712339099; darn=kvack.org; h=in-reply-to:content-transfer-encoding:content-disposition :mime-version:references:message-id:subject:cc:to:from:date:from:to :cc:subject:date:message-id:reply-to; bh=7WPAvDk3zSOm8wRKlGIEh/4VbBWjZSS4f1jGmiLObHs=; b=dczKONTBEY4qCX8RcS4odVhHbUpScGN6bZrF3tFNxyH6PpGjdQaAlBiPIAlIGnZJNn RGnAsSBiUQDpXAvmr20V3NK0TpHtAU4qXQP2Ks1xZ/RaBfZagXRDDfZt+OsRIu+YQZDB rZt6hl7A7EZ2VAI1WTSPtcVEN+c/auSB6oAfPHRTeV38GCz7US2OQfSPtOsXRzuR4RWn goSNZrxH/qftfuVsu7DrhfA1ZYDY97OLk+CFgmCMxaQF0dZoH77+l8+amaXIMv9dIKhF DsVtOPefyEkA0TULq4VTmHsMBGZdHpXUFrFAFWswEV/MrvgB6iVGHUMZAepgOfPXblrx 4yRg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1711734299; x=1712339099; h=in-reply-to:content-transfer-encoding:content-disposition :mime-version:references:message-id:subject:cc:to:from:date :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=7WPAvDk3zSOm8wRKlGIEh/4VbBWjZSS4f1jGmiLObHs=; b=JKAF2bU+/AB7Noyz3z1eg6fAxYVrQeWJH/aIN4xyGnZVuPC8rAibisbUcGXXVkyhfy /ciKy4QHT5BtHkesNQyi91B1phEIuRtHJV14tqFNwzSqJ7RiCwGGTtUC1D5MYW8ZTdCe z9rCsjreJeIqYV4E1hxSwCnSDjrGnM6WGZrKrjiiFjLuI6E5WVkJTRdK1H9SumP6qyc0 esyATXNCCrV9VRxQv6jiuqtHRf4ebloioYnC/8W2vN8u4PVFnXCNRCuj4QHq5ztM8mpW c0+makf1dbaq03a5U5Vn+a1GL9wxaGgBSrQir4qQBi+7S5PEAibPU9nwk6eGTD5yO+eU ENxw== X-Forwarded-Encrypted: i=1; AJvYcCXq6tyC/QJlGAfh8gErgHEoMwlJHylS9kHvp4bUwZIYJO+0WmU5s8tI3pQLfdDfMXNE+VIK68mWGcV8xpNk7npnN+A= X-Gm-Message-State: AOJu0Yz/vpsa9X/XuMcm21wxdwHzC/ClE+mmjBgPIuCpyGhaMDoFyoUg IBhw3AsYrRpfIEJZ93ZcwXOxpQp5dXXqKjm31ShkNhb6+uLLBy8w8OmH8D6kkRo= X-Google-Smtp-Source: AGHT+IEIzPlo+It4MAJPfvDzbeEPRL2P2vMXkvnLLN0ScdfPGcVa/y8QPQLon5sEmO5iFrWXPYciLg== X-Received: by 2002:a05:6870:231d:b0:22a:9ea4:c18 with SMTP id w29-20020a056870231d00b0022a9ea40c18mr3176254oao.15.1711734298746; Fri, 29 Mar 2024 10:44:58 -0700 (PDT) Received: from localhost ([2620:10d:c091:400::5:bb1f]) by smtp.gmail.com with ESMTPSA id k10-20020ac8604a000000b004313141f734sm1803750qtm.46.2024.03.29.10.44.58 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 29 Mar 2024 10:44:58 -0700 (PDT) Date: Fri, 29 Mar 2024 13:44:57 -0400 From: Johannes Weiner To: "Maciej S. Szmigiero" Cc: Yosry Ahmed , Andrew Morton , Nhat Pham , Chengming Zhou , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [RFC PATCH 5/9] mm: zswap: remove zswap_same_filled_pages_enabled Message-ID: <20240329174457.GJ7597@cmpxchg.org> References: <20240325235018.2028408-1-yosryahmed@google.com> <20240325235018.2028408-6-yosryahmed@google.com> <20240328191109.GE7597@cmpxchg.org> <19d5cdee-2868-41bd-83d5-6da75d72e940@maciej.szmigiero.name> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <19d5cdee-2868-41bd-83d5-6da75d72e940@maciej.szmigiero.name> X-Rspamd-Queue-Id: EDB351C0016 X-Rspam-User: X-Rspamd-Server: rspam11 X-Stat-Signature: tqmro3br3mk488oeqn8mk3bkscn1xgim X-HE-Tag: 1711734299-183846 X-HE-Meta: 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 GRIat5nK 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 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 Fri, Mar 29, 2024 at 03:02:10PM +0100, Maciej S. Szmigiero wrote: > On 29.03.2024 03:14, Yosry Ahmed wrote: > > On Thu, Mar 28, 2024 at 1:06 PM Yosry Ahmed wrote: > >> > >> On Thu, Mar 28, 2024 at 12:11 PM Johannes Weiner wrote: > >>> > >>> On Mon, Mar 25, 2024 at 11:50:13PM +0000, Yosry Ahmed wrote: > >>>> There is no logical reason to refuse storing same-filled pages more > >>>> efficiently and opt for compression. Remove the userspace knob. > >>>> > >>>> Signed-off-by: Yosry Ahmed > >>> > >>> Acked-by: Johannes Weiner > >>> > >>> I also think the non_same_filled_pages_enabled option should go > >>> away. Both of these tunables are pretty bizarre. > >> > >> Happy to remove both in the next version :) > > > > I thought non_same_filled_pages_enabled was introduced with the > > initial support for same-filled pages, but it was introduced > > separately (and much more recently): > > https://lore.kernel.org/all/7dbafa963e8bab43608189abbe2067f4b9287831.1641247624.git.maciej.szmigiero@oracle.com/ > > > > I am CCing Maciej to hear more about the use case for this. > > Thanks for CCing me. > > I introduced "non_same_filled_pages_enabled" a few years ago to > enable using zswap in a lightweight mode where it is only used for > its ability to store same-filled pages effectively. But all the pages it rejects go to disk swap instead, which is much slower than compression... > As far as I remember, there were some interactions between full > zswap and the cgroup memory controller - like, it made it easier > for an aggressive workload to exceed its cgroup memory.high limits. Ok, that makes sense! A container fairness measure, rather than a performance optimization. Fair enough, but that's moot then with cgroup accounting of the backing memory, f4840ccfca25 ("zswap: memcg accounting"). Thanks for prodiving context.