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]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 4008810F6FB7 for ; Wed, 1 Apr 2026 14:47:35 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 914A56B0005; Wed, 1 Apr 2026 10:47:34 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 8C5576B0088; Wed, 1 Apr 2026 10:47:34 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7DB1D6B0093; Wed, 1 Apr 2026 10:47:34 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 6F2E76B0005 for ; Wed, 1 Apr 2026 10:47:34 -0400 (EDT) Received: from smtpin03.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 171E11B88DE for ; Wed, 1 Apr 2026 14:47:34 +0000 (UTC) X-FDA: 84610265628.03.8D8553D Received: from stravinsky.debian.org (stravinsky.debian.org [82.195.75.108]) by imf20.hostedemail.com (Postfix) with ESMTP id 5E85D1C000A for ; Wed, 1 Apr 2026 14:47:32 +0000 (UTC) Authentication-Results: imf20.hostedemail.com; dkim=pass header.d=debian.org header.s=smtpauto.stravinsky header.b=fVUZv9jc ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1775054852; a=rsa-sha256; cv=none; b=cTfQx6HZPUBD/a6/Q+EfzS3cu9JoSwnATI23W85wRFKKgQ7pJ3Mieh9ZwdqVMqjxMFvU4a MV1J10E/6g0/seJeVhCUeDLroNAe1WmKk9Cn48aT9bt10SWkkQt2LqPPyK/mhVR9efSfUI S48s44as/Zz+RBNLWoO/QqD8oTvaLMc= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1775054852; 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=JnSPjif5Uaj42mJ9z9PRSlAuR5srdE7KzJ1Mpd5Z4zI=; b=ZMjiJF8ca5mDE1nved9s7oVUiCbh54uKblbIWP6Fytx7zVUx919Agbv+fr4cAcYia+fvC9 hh4Z/H5oi91wkz/7D0Xfarrf0Xvju+MbvgqNddlHvANoZNTclUvl8oJDyFYfj3CnCUcJ7J lnyKZzLIMuSW+10t8NRku9wYV9k1nb8= ARC-Authentication-Results: i=1; imf20.hostedemail.com; dkim=pass header.d=debian.org header.s=smtpauto.stravinsky header.b=fVUZv9jc; spf=none (imf20.hostedemail.com: domain of leitao@debian.org has no SPF policy when checking 82.195.75.108) smtp.mailfrom=leitao@debian.org; dmarc=none DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=debian.org; s=smtpauto.stravinsky; h=X-Debian-User:In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=JnSPjif5Uaj42mJ9z9PRSlAuR5srdE7KzJ1Mpd5Z4zI=; b=fVUZv9jcUfB/+Op9gRasnSrFPu 6a55c6PQIdS4o+sRVJ44OSIe6NEBgl2Dxj212AginiEqdcHZl1MUBwBU3dp4ihAqiZ5eKYISW2P6K rdLdgS9PxeQmrrtHBsmT6X+nZSgPYzJO7XwbZIixn/t822yrTmejacHJgqx1eKrOAkSNOdJPQT57W SNrAWjQ96b05a05NWrM+UtkvE1sJvNPFbap13V0thSO2/GKzgziT0GlJ3Xd8ycNFGUNR7Ce0CY5MH CI6/2U9WfkXRFvRLXKOI8En37s4QBbs+lVECDXvpbUPf/lneU6DiWjiaeWiOb5ZhE6zq6bCGCaezZ CDjjEfOg==; Received: from authenticated user by stravinsky.debian.org with esmtpsa (TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim 4.96) (envelope-from ) id 1w7wqs-0033kT-23; Wed, 01 Apr 2026 14:47:25 +0000 Date: Wed, 1 Apr 2026 07:47:19 -0700 From: Breno Leitao To: Andrew Morton , David Hildenbrand , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, kas@kernel.org, shakeel.butt@linux.dev, usama.arif@linux.dev, kernel-team@meta.com Subject: Re: [PATCH] mm/vmstat: spread vmstat_update requeue across the stat interval Message-ID: References: <20260401-vmstat-v1-1-b68ce4a35055@debian.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260401-vmstat-v1-1-b68ce4a35055@debian.org> X-Debian-User: leitao X-Rspam-User: X-Rspamd-Server: rspam11 X-Rspamd-Queue-Id: 5E85D1C000A X-Stat-Signature: hgeoxfxfufnzfh6nj3bbynzsu3wiap7e X-HE-Tag: 1775054852-819145 X-HE-Meta: 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 FMu8mTYQ oEujaXcINbdePZdrJyCIE6e6xYwHLftvdyFdH6cSjpLM5tmTEda9V9gGY51LWxcpnVDVkLlGKISjuuXv7hzj2xAGIPiPBEqqQq+b6POvThQgD1Z3dSrFu5HAVsiDYeIlGzJdLs7R1QOBx/NWH6gv3eYyQXaoIF8/RsSYnKua3Q2Uv9a3sEdavgv+kaw== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Wed, Apr 01, 2026 at 06:57:50AM -0700, Breno Leitao wrote: > free_pcppages_bulk contention (KASAN): > +--------------+----------+----------+ > | Metric | No fix | With fix | > +--------------+----------+----------+ > | Contentions | 872 | 117 | > | Total wait | 199.43ms | 80.76ms | > | Max wait | 4.19ms | 35.76ms | > +--------------+----------+----------+ > > Results without KASAN: > > free_pcppages_bulk contention (no KASAN): > +--------------+----------+----------+ > | Metric | No fix | With fix | > +--------------+----------+----------+ > | Contentions | 240 | 133 | > | Total wait | 34.01ms | 24.61ms | > | Max wait | 965us | 1.35ms | > +--------------+----------+----------+ Sorry, the Max wait time is inverted on both cases. free_pcppages_bulk contention (KASAN): +--------------+----------+----------+ | Metric | No fix | With fix | +--------------+----------+----------+ | Contentions | 872 | 117 | | Total wait | 199.43ms | 80.76ms | | Max wait | 35.76ms | 4.19ms | +--------------+----------+----------+ Results without KASAN: free_pcppages_bulk contention (no KASAN): +--------------+----------+----------+ | Metric | No fix | With fix | +--------------+----------+----------+ | Contentions | 240 | 133 | | Total wait | 34.01ms | 24.61ms | | Max wait | 1.35ms | 965us | +--------------+----------+----------+