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 D2771C28CF5 for ; Wed, 26 Jan 2022 11:24:30 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 2BB366B0072; Wed, 26 Jan 2022 06:24:30 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 26B636B0074; Wed, 26 Jan 2022 06:24:30 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 15A786B0075; Wed, 26 Jan 2022 06:24:30 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (relay025.a.hostedemail.com [64.99.140.25]) by kanga.kvack.org (Postfix) with ESMTP id 048106B0072 for ; Wed, 26 Jan 2022 06:24:30 -0500 (EST) Received: from smtpin02.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay13.hostedemail.com (Postfix) with ESMTP id BB2CD60F0B for ; Wed, 26 Jan 2022 11:24:29 +0000 (UTC) X-FDA: 79072205058.02.92B5802 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by imf10.hostedemail.com (Postfix) with ESMTP id CAFA8C0005 for ; Wed, 26 Jan 2022 11:24:28 +0000 (UTC) Date: Wed, 26 Jan 2022 12:24:25 +0100 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1643196266; 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=22UvY86Kfs4AbFGAcdoC8Kdx7cTmd+khf9zUEu3+8JU=; b=Y7kQkiCmXIll4GHMf/OXPjc7GbWHeMX4BK6a60kJv+OtHkOlHBIWzwoVlUecRRVSGLleqq xN0exkry7H3DhKWYBAycSgPYGE2nREK85PvJSSZxiqEwLbP6yfMYNXD5gZ55/XBHzBmUs4 P5epcx+y7dqy9Xh40pdCjwKrEjd2oIik+PPGmirzfJptqanxbweSltevfnCAEPTRKX1SQS +rCwDQj4W6YDWwWg/dIVUcbg93Z+K6M+K1jYKCoApUGInNkLU3HyDMlZTwmgYAD0CJ9I1W WbI5qs2CetZVCe6yGPVfH8hNPVtZ9r/MWOdLmkXCfF47Y5uXtGvABUB4uvnOrA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1643196266; 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=22UvY86Kfs4AbFGAcdoC8Kdx7cTmd+khf9zUEu3+8JU=; b=igt4CRlkzJpPqZFeay9GJE8KSEMkn9bNkM5J8GrPivTBxt7zcI40CakmKrJraSCsziuMtB dBEtsKhIHBrZkxCQ== From: Sebastian Andrzej Siewior To: Vlastimil Babka Cc: cgroups@vger.kernel.org, linux-mm@kvack.org, Andrew Morton , Johannes Weiner , Michal Hocko , Michal =?utf-8?Q?Koutn=C3=BD?= , Peter Zijlstra , Thomas Gleixner , Vladimir Davydov , Waiman Long Subject: Re: [PATCH 2/4] mm/memcg: Protect per-CPU counter by disabling preemption on PREEMPT_RT where needed. Message-ID: References: <20220125164337.2071854-1-bigeasy@linutronix.de> <20220125164337.2071854-3-bigeasy@linutronix.de> <86eeed07-b7dc-b387-ea4d-1a4a41334fe3@suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <86eeed07-b7dc-b387-ea4d-1a4a41334fe3@suse.cz> X-Stat-Signature: fsbuzc3ku8si9tdekxinisabn16uko5k X-Rspam-User: nil Authentication-Results: imf10.hostedemail.com; dkim=pass header.d=linutronix.de header.s=2020 header.b=Y7kQkiCm; dkim=pass header.d=linutronix.de header.s=2020e header.b=igt4CRlk; spf=pass (imf10.hostedemail.com: domain of bigeasy@linutronix.de designates 193.142.43.55 as permitted sender) smtp.mailfrom=bigeasy@linutronix.de; dmarc=pass (policy=none) header.from=linutronix.de X-Rspamd-Server: rspam01 X-Rspamd-Queue-Id: CAFA8C0005 X-HE-Tag: 1643196268-542920 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 2022-01-26 11:06:40 [+0100], Vlastimil Babka wrote: > So it's like c68ed7945701 ("mm/vmstat: protect per cpu variables with > preempt disable on RT") but we still don't want a wrapper of those > constructs so they don't spread further, right :) Right. We only have them because of assumption based on spin_lock_irq() which are not true on PREEMPT_RT. Having a generic one might let people to use them for the wrong reasons. The commit you mentioned changed all users while here I only changed those which missed it. Also I wasn't sure if preemption should be disabled or interrupts (to align with the other local_irq_save()). > Acked-by: Vlastimil Babka Thank you. Sebastian