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 D583FCD1293 for ; Mon, 1 Apr 2024 10:38:18 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id F40286B0083; Mon, 1 Apr 2024 06:38:17 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id EF0246B0085; Mon, 1 Apr 2024 06:38:17 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id DB7CD6B0088; Mon, 1 Apr 2024 06:38:17 -0400 (EDT) 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 BEAC66B0083 for ; Mon, 1 Apr 2024 06:38:17 -0400 (EDT) Received: from smtpin21.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id 7C02F405E8 for ; Mon, 1 Apr 2024 10:38:17 +0000 (UTC) X-FDA: 81960613434.21.B99D35A Received: from vps-vb.mhejs.net (vps-vb.mhejs.net [37.28.154.113]) by imf27.hostedemail.com (Postfix) with ESMTP id 73C5840017 for ; Mon, 1 Apr 2024 10:38:15 +0000 (UTC) Authentication-Results: imf27.hostedemail.com; dkim=none; spf=pass (imf27.hostedemail.com: domain of mail@maciej.szmigiero.name designates 37.28.154.113 as permitted sender) smtp.mailfrom=mail@maciej.szmigiero.name; dmarc=none ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1711967895; a=rsa-sha256; cv=none; b=LN/09/qYdmIgDFaD7/kmURgXegvqAzI59jrdLMgklO2IDUcgU2CqqoSPXK4nWhfKybVtz7 fhK/TYaYkCPGQL+FCTbXcXvFI/+96TOdWYRmpNHKCO9Ns3X3MYYoDgkLznMizQbumK9JUO D8qIfNU4Zhv34aFCPnhk7pJVEpJkFXI= ARC-Authentication-Results: i=1; imf27.hostedemail.com; dkim=none; spf=pass (imf27.hostedemail.com: domain of mail@maciej.szmigiero.name designates 37.28.154.113 as permitted sender) smtp.mailfrom=mail@maciej.szmigiero.name; dmarc=none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1711967895; 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; bh=QgwwRdFyFA1XQLi56vaeMF+Glmn5VFfZuxMmpwi/gWU=; b=fY7Myzysjf9ZtvanMpGHS0jeMKem8dvCZF0lBbkRZHIKPfjMlsJHWbVrFrzbROATFeasIx iAAVIx/Lt60Y61yCI6X0W7y/orkICubH5Sbumz3skPV+uFx85Ww/SPKuN1UOQ5mDrYtZQG nDtZMSoFMoA9t7JMwVgB1uyuobPquKo= Received: from MUA by vps-vb.mhejs.net with esmtps (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (Exim 4.94.2) (envelope-from ) id 1rrF3C-0000cd-Fg; Mon, 01 Apr 2024 12:38:02 +0200 Message-ID: Date: Mon, 1 Apr 2024 12:37:56 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [RFC PATCH 5/9] mm: zswap: remove zswap_same_filled_pages_enabled To: Yosry Ahmed Cc: Andrew Morton , Nhat Pham , Chengming Zhou , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Johannes Weiner 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> <20240329174457.GJ7597@cmpxchg.org> Content-Language: en-US, pl-PL From: "Maciej S. Szmigiero" Autocrypt: addr=mail@maciej.szmigiero.name; keydata= xsFNBFpGusUBEADXUMM2t7y9sHhI79+2QUnDdpauIBjZDukPZArwD+sDlx5P+jxaZ13XjUQc 6oJdk+jpvKiyzlbKqlDtw/Y2Ob24tg1g/zvkHn8AVUwX+ZWWewSZ0vcwp7u/LvA+w2nJbIL1 N0/QUUdmxfkWTHhNqgkNX5hEmYqhwUPozFR0zblfD/6+XFR7VM9yT0fZPLqYLNOmGfqAXlxY m8nWmi+lxkd/PYqQQwOq6GQwxjRFEvSc09m/YPYo9hxh7a6s8hAP88YOf2PD8oBB1r5E7KGb Fv10Qss4CU/3zaiyRTExWwOJnTQdzSbtnM3S8/ZO/sL0FY/b4VLtlZzERAraxHdnPn8GgxYk oPtAqoyf52RkCabL9dsXPWYQjkwG8WEUPScHDy8Uoo6imQujshG23A99iPuXcWc/5ld9mIo/ Ee7kN50MOXwS4vCJSv0cMkVhh77CmGUv5++E/rPcbXPLTPeRVy6SHgdDhIj7elmx2Lgo0cyh uyxyBKSuzPvb61nh5EKAGL7kPqflNw7LJkInzHqKHDNu57rVuCHEx4yxcKNB4pdE2SgyPxs9 9W7Cz0q2Hd7Yu8GOXvMfQfrBiEV4q4PzidUtV6sLqVq0RMK7LEi0RiZpthwxz0IUFwRw2KS/ 9Kgs9LmOXYimodrV0pMxpVqcyTepmDSoWzyXNP2NL1+GuQtaTQARAQABzTBNYWNpZWogUy4g U3ptaWdpZXJvIDxtYWlsQG1hY2llai5zem1pZ2llcm8ubmFtZT7CwZQEEwEIAD4CGwMFCwkI BwIGFQoJCAsCBBYCAwECHgECF4AWIQRyeg1N257Z9gOb7O+Ef143kM4JdwUCZdEV4gUJDWuO nQAKCRCEf143kM4JdyzED/0Qwk2KVsyNwEukYK2zbJPHp7CRbXcpCApgocVwtmdabAubtHej 7owLq89ibmkKT0gJxc6OfJJeo/PWTJ/Qo/+db48Y7y03Xl+rTbFyzsoTyZgdR21FQGdgNRG9 3ACPDpZ0UlEwA4VdGT+HKfu0X8pVb0G0D44DjIeHC7lBRzzE5JXJUGUVUd2FiyUqMFqZ8xP3 wp53ekB5p5OstceqyZIq+O/r1pTgGErZ1No80JrnVC/psJpmMpw1Q56t88JMaHIe+Gcnm8fB k3LyWNr7gUwVOus8TbkP3TOx/BdS/DqkjN3GvXauhVXfGsasmHHWEFBE0ijNZi/tD63ZILRY wUpRVRU2F0UqI+cJvbeG3c+RZ7jqMAAZj8NB8w6iviX1XG3amlbJgiyElxap6Za1SQ3hfTWf c6gYzgaNOFRh77PQbzP9BcAVDeinOqXg2IkjWQ89o0YVFKXiaDHKw7VVld3kz2FQMI8PGfyn zg5vyd9id1ykISCQQUQ4Nw49tqYoSomLdmIgPSfXDDMOvoDoENWDXPiMGOgDS2KbqRNYCNy5 KGQngJZNuDicDBs4r/FGt9/xg2uf8M5lU5b8vC78075c4DWiKgdqaIhqhSC+n+qcHX0bAl1L me9DMNm0NtsVw+mk65d7cwxHmYXKEGgzBcbVMa5C+Yevv+0GPkkwccIvps7AzQRaRrwiAQwA xnVmJqeP9VUTISps+WbyYFYlMFfIurl7tzK74bc67KUBp+PHuDP9p4ZcJUGC3UZJP85/GlUV dE1NairYWEJQUB7bpogTuzMI825QXIB9z842HwWfP2RW5eDtJMeujzJeFaUpmeTG9snzaYxY N3r0TDKj5dZwSIThIMQpsmhH2zylkT0jH7kBPxb8IkCQ1c6wgKITwoHFjTIO0B75U7bBNSDp XUaUDvd6T3xd1Fz57ujAvKHrZfWtaNSGwLmUYQAcFvrKDGPB5Z3ggkiTtkmW3OCQbnIxGJJw /+HefYhB5/kCcpKUQ2RYcYgCZ0/WcES1xU5dnNe4i0a5gsOFSOYCpNCfTHttVxKxZZTQ/rxj XwTuToXmTI4Nehn96t25DHZ0t9L9UEJ0yxH2y8Av4rtf75K2yAXFZa8dHnQgCkyjA/gs0ujG wD+Gs7dYQxP4i+rLhwBWD3mawJxLxY0vGwkG7k7npqanlsWlATHpOdqBMUiAR22hs02FikAo iXNgWTy7ABEBAAHCwXwEGAEIACYCGwwWIQRyeg1N257Z9gOb7O+Ef143kM4JdwUCZdEWBwUJ DWuNXAAKCRCEf143kM4Jd5OdD/0UXMpMd4eDWvtBBQkoOcz2SqsWwMj+vKPJS0BZ33MV/wXT PaTbzAFy23/JXbyBPcb0qgILCmoimBNiXDzYBfcwIoc9ycNwCMBBN47Jxwb8ES5ukFutjS4q +tPcjbPYu+hc9qzodl1vjAhaWjgqY6IzDGe4BAmM+L6UUID4Vr46PPN02bpm4UsL31J6X+lA Vj5WbY501vKMvTAiF1dg7RkHPX7ZVa0u7BPLjBLqu6NixNkpSRts8L9G4QDpIGVO7sOC9oOU 2h99VYY1qKml0qJ9SdTwtDj+Yxz+BqW7O4nHLsc4FEIjILjwF71ZKY/dlTWDEwDl5AJR7bhy HXomkWae2nBTzmWgIf9fJ2ghuCIjdKKwOFkDbFUkSs8HjrWymvMM22PHLTTGFx+0QbjOstEh 9i56FZj3DoOEfVKvoyurU86/4sxjIbyhqL6ZiTzuZAmB0RICOIGilm5x03ESkDztiuCtQL2u xNT833IQSNqyuEnxG9/M82yYa+9ClBiRKM2JyvgnBEbiWA15rAQkOqZGJfFJ3bmTFePx4R/I ZVehUxCRY5IS1FLe16tymf9lCASrPXnkO2+hkHpBCwt75wnccS3DwtIGqwagVVmciCxAFg9E WZ4dI5B0IUziKtBxgwJG4xY5rp7WbzywjCeaaKubtcLQ9bSBkkK4U8Fu58g6Hg== In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Rspam-User: X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: 73C5840017 X-Stat-Signature: hko55ixqhpbg3zxbh5geua17ne98trtz X-HE-Tag: 1711967895-458453 X-HE-Meta: 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 VTHULdAd Skzm4AcYoPUxKJT577MHEfiKuNqOsC3iLOOcAbTdxHzg1irYiXGhwPQpRAtrMrSkl3uk2kLlqO1V25WMj5WT4Bs/3aC9QaXhh2GPLdT9oeg95FI8fUi4ELWK5lDFopV2hLNsk6Os0zm++SVh2CUcFMQ2H+sx6qHaF9X8f0Ropf7//rBX3b7jBoKB8BEdLpwJe2xO4etuzLD/rYJA1/EGl5HISuUa3zfEbGZjx/XhWSVXmUUp/ByU/YiesqARc0UvTD0LnOFWwygtLnPHPS5jEbFUWt4fQ0ISLV5cyetmEyt3botRwDSgpzhpmwmyXNyMuuNJGm6IK8cQCCe3bmbYcuJSU76vuOXp605hL 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 29.03.2024 19:22, Yosry Ahmed wrote: > On Fri, Mar 29, 2024 at 10:45 AM Johannes Weiner wrote: >> >> 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"). > > Right, this should no longer be needed with the zswap charging. > > Maciej, is this still being used on kernels with f4840ccfca25 (5.19+)? > Any objections to removing it now? I don't object to its removal as long as stable kernel trees aren't affected. Thanks, Maciej