Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933018AbbBIIjg (ORCPT ); Mon, 9 Feb 2015 03:39:36 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:45127 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932880AbbBIIh4 (ORCPT ); Mon, 9 Feb 2015 03:37:56 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Sedat Dilek , "Paul E. McKenney" , Dave Hansen , Steven Rostedt Subject: [PATCH 3.18 39/39] x86/tlb/trace: Do not trace on CPU that is offline Date: Mon, 9 Feb 2015 16:34:22 +0800 Message-Id: <20150209083330.627711836@linuxfoundation.org> X-Mailer: git-send-email 2.3.0 In-Reply-To: <20150209083328.753647350@linuxfoundation.org> References: <20150209083328.753647350@linuxfoundation.org> User-Agent: quilt/0.63-1 MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3397 Lines: 93 3.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: "Steven Rostedt (Red Hat)" commit 6c8465a82a605bc692304bab42703017dcfff013 upstream. When taking a CPU down for suspend and resume, a tracepoint may be called when the CPU has been designated offline. As tracepoints require RCU for protection, they must not be called if the current CPU is offline. Unfortunately, trace_tlb_flush() is called in this scenario as was noted by LOCKDEP: ... Disabling non-boot CPUs ... intel_pstate CPU 1 exiting =============================== smpboot: CPU 1 didn't die... [ INFO: suspicious RCU usage. ] 3.19.0-rc7-next-20150204.1-iniza-small #1 Not tainted ------------------------------- include/trace/events/tlb.h:35 suspicious rcu_dereference_check() usage! other info that might help us debug this: RCU used illegally from offline CPU! rcu_scheduler_active = 1, debug_locks = 0 no locks held by swapper/1/0. stack backtrace: CPU: 1 PID: 0 Comm: swapper/1 Not tainted 3.19.0-rc7-next-20150204.1-iniza-small #1 Hardware name: SAMSUNG ELECTRONICS CO., LTD. 530U3BI/530U4BI/530U4BH/530U3BI/530U4BI/530U4BH, BIOS 13XK 03/28/2013 0000000000000001 ffff88011a44fe18 ffffffff817e370d 0000000000000011 ffff88011a448290 ffff88011a44fe48 ffffffff810d6847 ffff8800c66b9600 0000000000000001 ffff88011a44c000 ffffffff81cb3900 ffff88011a44fe78 Call Trace: [] dump_stack+0x4c/0x65 [] lockdep_rcu_suspicious+0xe7/0x120 [] idle_task_exit+0x205/0x2c0 [] play_dead_common+0xe/0x50 [] native_play_dead+0x15/0x140 [] arch_cpu_idle_dead+0xf/0x20 [] cpu_startup_entry+0x37e/0x580 [] start_secondary+0x140/0x150 intel_pstate CPU 2 exiting ... By converting the tlb_flush tracepoint to a TRACE_EVENT_CONDITION where the condition is cpu_online(smp_processor_id()), we can avoid calling RCU protected code when the CPU is offline. Link: http://lkml.kernel.org/r/CA+icZUUGiGDoL5NU8RuxKzFjoLjEKRtUWx=JB8B9a0EQv-eGzQ@mail.gmail.com Fixes: d17d8f9dedb9 "x86/mm: Add tracepoints for TLB flushes" Reported-by: Sedat Dilek Tested-by: Sedat Dilek Suggested-by: Paul E. McKenney Acked-by: Paul E. McKenney Acked-by: Dave Hansen Signed-off-by: Steven Rostedt Signed-off-by: Greg Kroah-Hartman diff --git a/include/trace/events/tlb.h b/include/trace/events/tlb.h index 13391d288107..0e7635765153 100644 --- a/include/trace/events/tlb.h +++ b/include/trace/events/tlb.h @@ -13,11 +13,13 @@ { TLB_LOCAL_SHOOTDOWN, "local shootdown" }, \ { TLB_LOCAL_MM_SHOOTDOWN, "local mm shootdown" } -TRACE_EVENT(tlb_flush, +TRACE_EVENT_CONDITION(tlb_flush, TP_PROTO(int reason, unsigned long pages), TP_ARGS(reason, pages), + TP_CONDITION(cpu_online(smp_processor_id())), + TP_STRUCT__entry( __field( int, reason) __field(unsigned long, pages) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/