From: Borislav Petkov <bp@alien8.de>
To: Jiri Kosina <jkosina@suse.cz>
Cc: Frederic Weisbecker <fweisbec@gmail.com>,
Tony Luck <tony.luck@intel.com>,
linux-kernel@vger.kernel.org, x86@kernel.org
Subject: Re: NOHZ: WARNING: at arch/x86/kernel/smp.c:123 native_smp_send_reschedule
Date: Fri, 10 May 2013 17:21:02 +0200 [thread overview]
Message-ID: <20130510152102.GD22942@pd.tnic> (raw)
In-Reply-To: <alpine.LNX.2.00.1305101702250.23038@pobox.suse.cz>
On Fri, May 10, 2013 at 05:03:56PM +0200, Jiri Kosina wrote:
> [ ... snip ... ]
> Enabling non-boot CPUs ...
> smpboot: Booting Node 0 Processor 1 APIC 0x1
> CPU1 microcode updated early to revision 0x60f, date = 2010-09-29
> Disabled fast string operations
> 1 1
> CPU: 1 PID: 0 Comm: swapper/1 Not tainted 3.9.0-12317-gb2031d4 #1
> Hardware name: LENOVO 7470BN2/7470BN2, BIOS 6DET38WW (2.02 ) 12/19/2008
> ffff88007c28cca0 ffff880079851e08 ffffffff8154837e ffff880079851e28
> ffffffff81077514 ffff88007c28cca0 ffff88007c28cca0 ffff880079851e68
> ffffffff810529db 0000000179851e78 ffff88007c28cca0 0000000000000001
> Call Trace:
> [<ffffffff8154837e>] dump_stack+0x19/0x1b
> [<ffffffff81077514>] wake_up_nohz_cpu+0xd4/0xf0
> [<ffffffff810529db>] add_timer_on+0xdb/0x110
> [<ffffffff8101e4f4>] mce_start_timer+0x64/0x70
> [<ffffffff8101e552>] __mcheck_cpu_init_timer+0x52/0x60
> [<ffffffff8153e22e>] mcheck_cpu_init+0x6f/0x111
> [<ffffffff8153b94e>] identify_cpu+0x3cc/0x3f9
> [<ffffffff8153b98d>] identify_secondary_cpu+0x12/0x1d
> [<ffffffff8153fdd6>] smp_store_cpu_info+0x3a/0x3c
> [<ffffffff8153fec2>] smp_callin+0xea/0x1c1
> [<ffffffff8153ffbd>] start_secondary+0x24/0x97
Ok, I got it:
smp_callin is called by start_secondary() and down that path we add the
timer and do wake_up_nohz_cpu.
HOWEVER(!), the bit in the cpu_online_mask is set much later in
smp_callin() with
set_cpu_online(smp_processor_id(), true);
Thus, when we come to send the IPI, the cpu is still offline, according
to the cpu_online_mask, thus the WARN_ON.
Nice :-\
--
Regards/Gruss,
Boris.
Sent from a fat crate under my desk. Formatting is fine.
--
next prev parent reply other threads:[~2013-05-10 15:14 UTC|newest]
Thread overview: 54+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-05-09 12:29 NOHZ: WARNING: at arch/x86/kernel/smp.c:123 native_smp_send_reschedule Jiri Kosina
2013-05-09 12:50 ` Borislav Petkov
2013-05-09 12:58 ` Borislav Petkov
2013-05-15 18:45 ` Paul E. McKenney
2013-05-15 22:43 ` Borislav Petkov
2013-05-15 23:55 ` Paul E. McKenney
2013-05-17 13:56 ` NOHZ: WARNING: at arch/x86/kernel/smp.c:123 native_smp_send_reschedule, round 2 Borislav Petkov
2013-05-20 3:16 ` Michael Wang
2013-05-20 4:50 ` Borislav Petkov
2013-05-20 6:23 ` Michael Wang
2013-05-20 6:47 ` Borislav Petkov
2013-05-20 6:58 ` Michael Wang
2013-05-20 7:06 ` Michael Wang
2013-05-20 7:12 ` Viresh Kumar
2013-05-20 7:25 ` Michael Wang
2013-05-20 8:56 ` Michael Wang
2013-05-20 9:09 ` Viresh Kumar
2013-05-20 9:24 ` Michael Wang
2013-05-20 13:23 ` Borislav Petkov
2013-05-20 13:43 ` Viresh Kumar
2013-05-20 15:08 ` Borislav Petkov
2013-05-21 2:20 ` Michael Wang
2013-05-21 2:37 ` Michael Wang
2013-05-21 7:21 ` Borislav Petkov
2013-05-21 7:58 ` Michael Wang
2013-05-20 7:36 ` Tejun Heo
2013-05-20 8:10 ` Frederic Weisbecker
2013-05-20 9:31 ` Srivatsa S. Bhat
2013-05-20 9:40 ` Viresh Kumar
2013-05-20 10:24 ` Viresh Kumar
2013-06-04 21:20 ` Jiri Kosina
2013-06-05 2:30 ` Michael Wang
2013-06-05 8:08 ` Jiri Kosina
2013-06-05 8:12 ` Michael Wang
2013-05-10 0:29 ` NOHZ: WARNING: at arch/x86/kernel/smp.c:123 native_smp_send_reschedule Frederic Weisbecker
2013-05-10 9:28 ` Borislav Petkov
2013-05-10 9:26 ` Frederic Weisbecker
2013-05-10 9:37 ` Ingo Molnar
2013-05-10 9:45 ` Borislav Petkov
2013-05-10 15:31 ` Frederic Weisbecker
2013-05-10 9:43 ` Borislav Petkov
2013-05-10 15:42 ` Jiri Kosina
2013-05-10 15:03 ` Jiri Kosina
2013-05-10 15:21 ` Borislav Petkov [this message]
2013-05-10 15:43 ` Frederic Weisbecker
2013-05-10 16:23 ` Borislav Petkov
2013-05-10 21:38 ` Frederic Weisbecker
2013-05-13 14:56 ` Jiri Kosina
2013-05-13 19:40 ` Thomas Gleixner
2013-05-13 20:01 ` Jiri Kosina
2013-05-14 15:46 ` [tip:timers/urgent] tick: Don't invoke tick_nohz_stop_sched_tick( ) if the cpu is offline tip-bot for Thomas Gleixner
2013-05-15 19:41 ` Frederic Weisbecker
2013-05-16 14:06 ` Thomas Gleixner
2013-05-16 14:15 ` Borislav Petkov
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