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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 34E27C54EBC for ; Tue, 10 Jan 2023 12:11:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231866AbjAJMLj (ORCPT ); Tue, 10 Jan 2023 07:11:39 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56480 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232513AbjAJMKs (ORCPT ); Tue, 10 Jan 2023 07:10:48 -0500 X-Greylist: delayed 484 seconds by postgrey-1.37 at lindbergh.monkeyblade.net; Tue, 10 Jan 2023 04:07:08 PST Received: from gentwo.de (gentwo.de [161.97.139.209]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E045C77AC4 for ; Tue, 10 Jan 2023 04:07:08 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gentwo.de; s=default; t=1673352397; bh=1lAq3hxMorwKertNBHt6kodNs2aKb8MmxSA/uvyQtjI=; h=Date:From:To:cc:Subject:In-Reply-To:References:From; b=Q2xOroI33ZBTvLTbLZwgBXoIRIs84is0yynUPd9GoLmqA6ebjP/UR0zYS08ftSNrW XOnKoF5DzEnL23E+hVNwl9Vs53uU52aTtB0uMYdSP9hEGSon47b0JoRAsTz5/aaB0r tTIcK880hwzSR5/kxQeocCubyGDh4EtOsaav3CniPZBwWmr3c+uUqk75Xavl/8go0R fzN9eM+3w28PUVXRErsJHdTSiCegBrzoDYVcei18VIVh6rvT5QW+VyxGxDsXmg9tDL SO1uE+yGzu5YoPSmHq7NVvhUC4oh9+bO6DYBrtY0kCsmD8h37xK3QQpGlbipmV/jmy F1gXNMICSffMw== Received: by gentwo.de (Postfix, from userid 1001) id 438A9B0021D; Tue, 10 Jan 2023 13:06:37 +0100 (CET) Received: from localhost (localhost [127.0.0.1]) by gentwo.de (Postfix) with ESMTP id 41B09B00136; Tue, 10 Jan 2023 13:06:37 +0100 (CET) Date: Tue, 10 Jan 2023 13:06:37 +0100 (CET) From: Christoph Lameter To: Marcelo Tosatti cc: atomlin@atomlin.com, frederic@kernel.org, tglx@linutronix.de, mingo@kernel.org, peterz@infradead.org, pauld@redhat.com, neelx@redhat.com, oleksandr@natalenko.name, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH v13 2/6] mm/vmstat: Use vmstat_dirty to track CPU-specific vmstat discrepancies In-Reply-To: <20230105125248.813825852@redhat.com> Message-ID: References: <20230105125218.031928326@redhat.com> <20230105125248.813825852@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 5 Jan 2023, Marcelo Tosatti wrote: > --- linux-2.6.orig/mm/vmstat.c > +++ linux-2.6/mm/vmstat.c > @@ -381,6 +381,7 @@ void __mod_zone_page_state(struct zone * > x = 0; > } > __this_cpu_write(*p, x); > + vmstat_mark_dirty(); __vmstat_mark_dirty()? See earlier patch > > preempt_enable_nested(); > } > @@ -417,6 +418,7 @@ void __mod_node_page_state(struct pglist > x = 0; > } > __this_cpu_write(*p, x); > + vmstat_mark_dirty(); Ditto. > > preempt_enable_nested(); > } > @@ -577,6 +579,9 @@ static inline void mod_zone_state(struct > s8 __percpu *p = pcp->vm_stat_diff + item; > long o, n, t, z; > > + /* cmpxchg and vmstat_mark_dirty should happen on the same CPU */ > + preempt_disable(); If you are disabling preemption then why do we still need cmpxchg? Same again below.