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 4ABB9C83F1B for ; Mon, 14 Jul 2025 17:59:56 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id C99788D0010; Mon, 14 Jul 2025 13:59:55 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id C4A108D0001; Mon, 14 Jul 2025 13:59:55 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B5FC48D0010; Mon, 14 Jul 2025 13:59:55 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id A5AEA8D0001 for ; Mon, 14 Jul 2025 13:59:55 -0400 (EDT) Received: from smtpin24.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id 675888025E for ; Mon, 14 Jul 2025 17:59:55 +0000 (UTC) X-FDA: 83663633550.24.C6DE245 Received: from out-189.mta1.migadu.com (out-189.mta1.migadu.com [95.215.58.189]) by imf17.hostedemail.com (Postfix) with ESMTP id B27B040008 for ; Mon, 14 Jul 2025 17:59:53 +0000 (UTC) Authentication-Results: imf17.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=wkiFqcKG; spf=pass (imf17.hostedemail.com: domain of roman.gushchin@linux.dev designates 95.215.58.189 as permitted sender) smtp.mailfrom=roman.gushchin@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1752515994; a=rsa-sha256; cv=none; b=xyK0TbvOY5NzVhj/GLoCrbSZgZe3ReCYjpRQSbuAnQj2L5Y5pj/KKs/XdTKgZoEqU87lMG iQ/cGX8ADxa/SeuzkpOaGFlOouNZBVn65fa0z9WBEjWKQsyg14FfzWGr2mDNL9GLlbjRB6 FF6HYCVbNSArnI01miA2gBX5xrm9dpw= ARC-Authentication-Results: i=1; imf17.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=wkiFqcKG; spf=pass (imf17.hostedemail.com: domain of roman.gushchin@linux.dev designates 95.215.58.189 as permitted sender) smtp.mailfrom=roman.gushchin@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1752515994; 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: in-reply-to:in-reply-to:references:references:dkim-signature; bh=0wB95BviQqkbgDYRbFJTZzuB7lkYloJSHBXsqNvJjNw=; b=AFc26CL2W9ORTTGjL6mlY/R/yM81FCD/RzMiAyXJgAa85uKx38u5CsFurQcA0pF7Ulx/qm G7Kwms8/jqwJxzyUgaT4u6/eY05UlO0ng4kNNg8Tjm3SFwahwtQEvIySOtWBTU0T3GdbM3 yqEK09X5ML14psG7m30RWZglpz+DnjM= X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1752515991; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=0wB95BviQqkbgDYRbFJTZzuB7lkYloJSHBXsqNvJjNw=; b=wkiFqcKGJXXvzgTTJcb8BqQVT/NWaQp//L9NZ8DURWu3DS70htzRhHBxTX+5rl3ZGYpafk ILZhcfJqDQ0Hc7iAvIUzbsahAjY3mxPjSfa4pE3iELRuVXOO1Hn44HpNMrx9OprXwsjxry dl7m2QWbjrJoFbZ9EFUXo4WNWyT7/+c= From: Roman Gushchin To: Hugh Dickins Cc: Andrew Morton , Johannes Weiner , Shakeel Butt , Lorenzo Stoakes , Michal Hocko , David Hildenbrand , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] mm: skip lru_note_cost() when scanning only file or anon In-Reply-To: <21100102-51b6-79d5-03db-1bb7f97fa94c@google.com> (Hugh Dickins's message of "Sun, 13 Jul 2025 12:57:18 -0700 (PDT)") References: <20250711155044.137652-1-roman.gushchin@linux.dev> <8734b21tie.fsf@linux.dev> <21100102-51b6-79d5-03db-1bb7f97fa94c@google.com> Date: Mon, 14 Jul 2025 10:59:45 -0700 Message-ID: <878qkqslf2.fsf@linux.dev> MIME-Version: 1.0 Content-Type: text/plain X-Migadu-Flow: FLOW_OUT X-Rspam-User: X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: B27B040008 X-Stat-Signature: 5zswc5bq3kpuih9rtxbh5ksjrrhzbm1p X-HE-Tag: 1752515993-973698 X-HE-Meta: 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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: Hugh Dickins writes: > Roman, I'm expressing no opinion on your patch above, but please may I > throw the patch below (against 6.16-rc) over the wall to you, to add as a > 1/2 or 2/2 to yours (as it stands, it does conflict slightly with yours). > > My attention needs to be on other things; but five years ago in > https://lore.kernel.org/linux-mm/alpine.LSU.2.11.2009211440570.5214@eggly.anvils/ > I noted how lru_note_cost() became more costly with per-memcg lru_lock, > but did nothing about it at the time. Apparently now is the time. > > Thanks, > Hugh > > [PATCH] mm: lru_note_cost_unlock_irq() > > Dropping a lock, just to demand it again for an afterthought, cannot be > good if contended: convert lru_note_cost() to lru_note_cost_unlock_irq(). > > Signed-off-by: Hugh Dickins Reviewed-by: Roman Gushchin Tested-by: Roman Gushchin Thanks, Hugh! Actually your patch helps quite a lot with the lruvec lock contention in my test, so I think we can stop looking at my change from the performance point of view.