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 7A4FCC433EF for ; Thu, 31 Mar 2022 06:40:01 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 0BD7F6B0072; Thu, 31 Mar 2022 02:40:01 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 06DA88D0001; Thu, 31 Mar 2022 02:40:01 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E78116B0074; Thu, 31 Mar 2022 02:40:00 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (relay.a.hostedemail.com [64.99.140.24]) by kanga.kvack.org (Postfix) with ESMTP id D73066B0072 for ; Thu, 31 Mar 2022 02:40:00 -0400 (EDT) Received: from smtpin04.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 9A10F245D1 for ; Thu, 31 Mar 2022 06:40:00 +0000 (UTC) X-FDA: 79303731360.04.8F183FA Received: from mail-yb1-f202.google.com (mail-yb1-f202.google.com [209.85.219.202]) by imf16.hostedemail.com (Postfix) with ESMTP id 26F4F180015 for ; Thu, 31 Mar 2022 06:40:00 +0000 (UTC) Received: by mail-yb1-f202.google.com with SMTP id y10-20020a5b0d0a000000b00633b9765410so17293674ybp.18 for ; Wed, 30 Mar 2022 23:39:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc:content-transfer-encoding; bh=2EO1zCBkMeInrvtUm5zFLSJgdsvUYdhYvGrInIQEHn8=; b=BuraXhTICGesUuAWshpPBGws+qpwfbbToioiwotOHb/5C7i4EF/ANXjMpswRm2Amcy NzVB9MrpgHzoXUX4+6yujhXOdX4S1tUk9vWlZGm39O2Mikz+KUApMWDYtFXEqkYh7Luw zyh+TARfdaiF3PszRIMmm/mzUHOeGUT/0fWReMG5Fyj9dn/LjNoGbC1OWvFCT2tk06ge aQfZPXeGJ4grNqItzGlUsH0WFjVwzTPu2I1HyXPDW/RnZlPBtSUJ3984lac5I3jwsNvD srATOlGPmkvXo3TEQ3WQ4pHZ55OCSFX93ec/0vMwhOd5xmRlCWLOoolX/XTXpiNH9uyq AqIg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc:content-transfer-encoding; bh=2EO1zCBkMeInrvtUm5zFLSJgdsvUYdhYvGrInIQEHn8=; b=VyKCRCf6Q9dQlaIfN8CNczq8Opao2v1fzdcUP2G0gPn7Y3QAw7S1kF8bt+CX8K8zjr I6mhemIcErKhwVkyiYFTUOZYOtzpyAegrgJNKY9s/YGKGf3VNAr+G7GVLBHD7W8yoWfH VIMOhyFMRpvGaYzGKB4rFTbArLyllIKpBBicQYeI2RcimDyNz38K00S1c+nC10QqvuNt DLKzjWnh3WZEg33aN68gSleQZ/UEuLjaIgreWWdsR/ily+ZlgXprP66/bsk8rpJklsBJ XpV522vfYV5wKuxZUVEuNwOpFynPv33AfRI66/DEqPLYhjLNDTIeuehKTzKOyf0HZ769 dJbQ== X-Gm-Message-State: AOAM530YT8dVutel/81TQPhIpQ/MItSGsC9HQxC6ZUDAUPKauWZjFT+M QKREfLurbMSfphkxIZyc24B9cM2vP0y3kw== X-Google-Smtp-Source: ABdhPJyt7GDJgAVqiqYMHwpK4PthMSnXQEN6sLNCWOjUDvSjiidXMxyP21GtktoorZ34FUmloIhvrzRQBKD8QA== X-Received: from shakeelb.c.googlers.com ([fda3:e722:ac3:cc00:20:ed76:c0a8:28b]) (user=shakeelb job=sendgmr) by 2002:a25:b889:0:b0:633:c93e:3e18 with SMTP id w9-20020a25b889000000b00633c93e3e18mr3141444ybj.263.1648708799467; Wed, 30 Mar 2022 23:39:59 -0700 (PDT) Date: Thu, 31 Mar 2022 06:39:56 +0000 In-Reply-To: <89B53D3A-FCC5-4107-8D49-81D5B9AE5172@linux.dev> Message-Id: <20220331063956.5uqnab64cqnmcwyr@google.com> Mime-Version: 1.0 References: <20220330191440.1cc1b2de2b849d1ba93d2ba7@linux-foundation.org> <89B53D3A-FCC5-4107-8D49-81D5B9AE5172@linux.dev> Subject: Re: [PATCH v2] mm/list_lru: Fix possible race in memcg_reparent_list_lru_node() From: Shakeel Butt To: Roman Gushchin Cc: Andrew Morton , Waiman Long , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Muchun Song Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 26F4F180015 X-Stat-Signature: 3tdi4swgjzrn1j8pbz8acqafrcx6ykmr Authentication-Results: imf16.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b=BuraXhTI; dmarc=pass (policy=reject) header.from=google.com; spf=pass (imf16.hostedemail.com: domain of 3v0xFYggKCIY2rkuoovlqyyqvo.mywvsx47-wwu5kmu.y1q@flex--shakeelb.bounces.google.com designates 209.85.219.202 as permitted sender) smtp.mailfrom=3v0xFYggKCIY2rkuoovlqyyqvo.mywvsx47-wwu5kmu.y1q@flex--shakeelb.bounces.google.com X-Rspam-User: X-HE-Tag: 1648708800-742529 X-Bogosity: Ham, tests=bogofilter, spamicity=0.092517, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed, Mar 30, 2022 at 07:48:45PM -0700, Roman Gushchin wrote: >=20 >=20 [...] >=20 >=20 > But honestly, I=E2=80=99d drop the original optimization together with th= e fix, if only there is no _real world_ data on the problem and the improve= ment. It seems like it has started as a nice simple improvement, but the ra= ce makes it complex and probably not worth the added complexity and fragili= ty. I agree with dropping the original optimization as it is not really fixing an observed issue which may justify adding some complexity. thanks, Shakeel