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 X-Spam-Level: X-Spam-Status: No, score=-10.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CD966C433B4 for ; Wed, 31 Mar 2021 17:42:46 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 4BC3361026 for ; Wed, 31 Mar 2021 17:42:46 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4BC3361026 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linutronix.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id A66F06B007E; Wed, 31 Mar 2021 13:42:45 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id A16AB6B0080; Wed, 31 Mar 2021 13:42:45 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9051C6B0081; Wed, 31 Mar 2021 13:42:45 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0027.hostedemail.com [216.40.44.27]) by kanga.kvack.org (Postfix) with ESMTP id 721F36B007E for ; Wed, 31 Mar 2021 13:42:45 -0400 (EDT) Received: from smtpin14.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 2659B3638 for ; Wed, 31 Mar 2021 17:42:45 +0000 (UTC) X-FDA: 77980889490.14.18C96BB Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by imf15.hostedemail.com (Postfix) with ESMTP id 3BC37A00038A for ; Wed, 31 Mar 2021 17:42:44 +0000 (UTC) From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1617212562; 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=C967zpewr99fjORRJqIiBkZCuEwXzxaSkRDZao7dYL4=; b=4VcxFKDux1F1dnBF2huA55CyIjECtZ+hb6FlSSQe9/ETlERsswt1uMzgsR7Ufnyhv/Vf21 3nUxMMoy8k2k7PxgE4gNw7Y3+tpo46/+8KZ2xqas+dAL22Yp1shwzplF3FcwufbZCOz8EV zNY6TCc+F5xDLkE7Q/EN1fqaZu3eGEVX6SDiiX0Bj5kLTblxAHpajRyc4NvWLi51Sljabw gDy6i65ZkNrAytcv47i+U3oucFVBbqI1fn+D914DnYnCvZ42PNTfZWVyC4ulMhAOjWg0vF 0tDaoy0f45ed/kIrMYsUwIugmOwGK7Rm+g0YGcvPJuxewhJeSVP2nwGrxyhpkw== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1617212562; 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=C967zpewr99fjORRJqIiBkZCuEwXzxaSkRDZao7dYL4=; b=WeqxWCG+/VHYOYpCeH8Lx9mj5dDp/27+7rgsWQYstPZ3CJ5MegtJcGmVs/DaHYz6Q+VqYk UsiVd/EaTJKiLaCA== To: Mel Gorman Cc: Linux-MM , Linux-RT-Users , LKML , Chuck Lever , Jesper Dangaard Brouer , Matthew Wilcox , Sebastian Andrzej Siewior Subject: Re: [PATCH 2/6] mm/page_alloc: Convert per-cpu list protection to local_lock In-Reply-To: <20210331110137.GA3697@techsingularity.net> References: <20210329120648.19040-1-mgorman@techsingularity.net> <20210329120648.19040-3-mgorman@techsingularity.net> <877dln640j.ffs@nanos.tec.linutronix.de> <20210331110137.GA3697@techsingularity.net> Date: Wed, 31 Mar 2021 19:42:42 +0200 Message-ID: <871rbv5iel.ffs@nanos.tec.linutronix.de> MIME-Version: 1.0 Content-Type: text/plain X-Rspamd-Queue-Id: 3BC37A00038A X-Stat-Signature: xprfxiycuoxzcf1scjcknf83te7s73u3 X-Rspamd-Server: rspam02 Received-SPF: none (linutronix.de>: No applicable sender policy available) receiver=imf15; identity=mailfrom; envelope-from=""; helo=galois.linutronix.de; client-ip=193.142.43.55 X-HE-DKIM-Result: pass/pass X-HE-Tag: 1617212564-814913 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: On Wed, Mar 31 2021 at 12:01, Mel Gorman wrote: > On Wed, Mar 31, 2021 at 11:55:56AM +0200, Thomas Gleixner wrote: > @@ -887,13 +887,11 @@ void cpu_vm_stats_fold(int cpu) > > pzstats = per_cpu_ptr(zone->per_cpu_zonestats, cpu); > > - preempt_disable(); > for (i = 0; i < NR_VM_ZONE_STAT_ITEMS; i++) > if (pzstats->vm_stat_diff[i]) { > int v; > > - v = pzstats->vm_stat_diff[i]; > - pzstats->vm_stat_diff[i] = 0; > + v = this_cpu_xchg(pzstats->vm_stat_diff[i], 0); Confused. pzstats is not a percpu pointer. zone->per_cpu_zonestats is. But @cpu is not necessarily the current CPU. Thanks, tglx