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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no 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 99149C48BE8 for ; Mon, 14 Jun 2021 11:16:25 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 3DB4760D07 for ; Mon, 14 Jun 2021 11:16:25 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3DB4760D07 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 A90436B006C; Mon, 14 Jun 2021 07:16:24 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id A402B6B006E; Mon, 14 Jun 2021 07:16:24 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 86B496B0070; Mon, 14 Jun 2021 07:16:24 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0031.hostedemail.com [216.40.44.31]) by kanga.kvack.org (Postfix) with ESMTP id 50A426B006C for ; Mon, 14 Jun 2021 07:16:24 -0400 (EDT) Received: from smtpin29.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id E5819180AD807 for ; Mon, 14 Jun 2021 11:16:23 +0000 (UTC) X-FDA: 78252075846.29.8F67B50 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by imf02.hostedemail.com (Postfix) with ESMTP id ACFE14202A2A for ; Mon, 14 Jun 2021 11:16:18 +0000 (UTC) Date: Mon, 14 Jun 2021 13:16:19 +0200 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1623669381; 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=++e4A/S400E85MA7JQbxrze69YWqU4ooV/kaCLvdV1M=; b=LrPKSkXilgXlJ80Tlo2vEln+cxsJ/bOVcQL9pwU4dfucv71qBhsKGEn6/kvL2TPJ/SJlrA 2bz3ynWqUuT8TYrRp4FNF3WySeWXE4fL7Z5Yp05grcyC+BJIkmEA+hkM3Nfkf+ddCDVMY2 MjEpGbLZ5Iir4mbVH4FOK/vyVca4vJf6yHyxhokjHm0j/R6B8jPSC5bxZTJ1piZIe6ku1f RtRmaUqkRdONvxV38zafFtjdw6QAwA8GgYJQXgz9TnNieTnSwN2VUGgFuEqDZa9Am5TAre MYeKV7DAmeHIx5b4HsC3Ueqtld+KPJyCYrVTbr3APyTu8X35cxqXjsZSYqH7OQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1623669381; 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=++e4A/S400E85MA7JQbxrze69YWqU4ooV/kaCLvdV1M=; b=7t5RdSbKecVbT7rqp3zRhYOnZm2a/qTFJ9Y569zzdkoOCsTDGP2ZN065AYWGbOAOlmnT+a 1nBIEkCUO7ty+BAA== From: Sebastian Andrzej Siewior To: Vlastimil Babka Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Christoph Lameter , David Rientjes , Pekka Enberg , Joonsoo Kim , Thomas Gleixner , Mel Gorman , Jesper Dangaard Brouer , Peter Zijlstra , Jann Horn Subject: Re: [RFC v2 33/34] mm, slub: use migrate_disable() on PREEMPT_RT Message-ID: <20210614111619.l3ral7tt2wasvlb4@linutronix.de> References: <20210609113903.1421-1-vbabka@suse.cz> <20210609113903.1421-34-vbabka@suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: Authentication-Results: imf02.hostedemail.com; dkim=pass header.d=linutronix.de header.s=2020 header.b=LrPKSkXi; dkim=pass header.d=linutronix.de header.s=2020e header.b=7t5RdSbK; dmarc=pass (policy=none) header.from=linutronix.de; spf=pass (imf02.hostedemail.com: domain of bigeasy@linutronix.de designates 193.142.43.55 as permitted sender) smtp.mailfrom=bigeasy@linutronix.de X-Stat-Signature: j4srey875inzzkk4btsj65emsmxugisz X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: ACFE14202A2A X-HE-Tag: 1623669378-400214 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 2021-06-14 13:07:14 [+0200], Vlastimil Babka wrote: > > +#ifdef CONFIG_PREEMPT_RT > > +#define slub_get_cpu_ptr(var) get_cpu_ptr(var) > > +#define slub_put_cpu_ptr(var) put_cpu_ptr(var) > > After Mel's report and bisect pointing to this patch, I realized I got the > #ifdef wrong and it should be #ifnded So if you got the ifdef wrong (and kept everything as-is) then you tested the RT version on !RT. migrate_disable() behaves on !RT as on RT. As per changelog you don't use migrate_disable() unconditionally because it increases the overhead on !RT. I haven't looked at the series and I have just this tiny question: why did migrate_disable() crash for Mel on !RT and why do you expect that it does not happen on PREEMPT_RT? Sebastian