From: Wanpeng Li <kernellwp@gmail.com>
To: linux-kernel@vger.kernel.org
Cc: Wanpeng Li <wanpeng.li@hotmail.com>,
Ingo Molnar <mingo@kernel.org>, Mike Galbraith <efault@gmx.de>,
Peter Zijlstra <peterz@infradead.org>,
Thomas Gleixner <tglx@linutronix.de>
Subject: [PATCH] x86/smp: Add irq_enter/exit() in smp_reschedule_interrupt()
Date: Fri, 14 Oct 2016 09:48:53 +0800 [thread overview]
Message-ID: <1476409733-5133-1-git-send-email-wanpeng.li@hotmail.com> (raw)
===============================
[ INFO: suspicious RCU usage. ]
4.8.0+ #24 Not tainted
-------------------------------
./arch/x86/include/asm/msr-trace.h:47 suspicious rcu_dereference_check() usage!
other info that might help us debug this:
RCU used illegally from idle CPU!
rcu_scheduler_active = 1, debug_locks = 0
RCU used illegally from extended quiescent state!
no locks held by swapper/1/0.
stack backtrace:
CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.8.0+ #24
Hardware name: Dell Inc. OptiPlex 7020/0F5C5X, BIOS A03 01/08/2015
ffff90285de03f58 ffffffff9d44a0c9 ffff90285ca5d100 0000000000000001
ffff90285de03f88 ffffffff9d0ebd67 ffff902845165410 000000000000080b
0000000000000000 0000000000000000 ffff90285de03fb8 ffffffff9d492b95
Call Trace:
<IRQ> [<ffffffff9d44a0c9>] dump_stack+0x99/0xd0
[<ffffffff9d0ebd67>] lockdep_rcu_suspicious+0xe7/0x120
[<ffffffff9d492b95>] do_trace_write_msr+0x135/0x140
[<ffffffff9d06f860>] native_write_msr+0x20/0x30
[<ffffffff9d065fad>] native_apic_msr_eoi_write+0x1d/0x30
[<ffffffff9d05bd1d>] smp_reschedule_interrupt+0x1d/0x30
[<ffffffff9d8daec6>] reschedule_interrupt+0x96/0xa0
<EOI> [<ffffffff9d732634>] ? cpuidle_enter_state+0xe4/0x360
[<ffffffff9d73261f>] ? cpuidle_enter_state+0xcf/0x360
[<ffffffff9d7328e7>] cpuidle_enter+0x17/0x20
[<ffffffff9d0e1a73>] call_cpuidle+0x23/0x50
[<ffffffff9d0e1d0c>] cpu_startup_entry+0x15c/0x280
[<ffffffff9d05ce64>] start_secondary+0x154/0x180
Reschedule interrupt may be called in cpu idle state. This causes lockdep
check warning above.
Add irq_enter/exit() in smp_reschedule_interrupt(), irq_enter() tells the RCU
subsystems to end the extended quiescent state, so the following trace call in
ack_APIC_irq() works correctly.
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
---
arch/x86/kernel/smp.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/arch/x86/kernel/smp.c b/arch/x86/kernel/smp.c
index 658777c..ac2ee87 100644
--- a/arch/x86/kernel/smp.c
+++ b/arch/x86/kernel/smp.c
@@ -259,8 +259,10 @@ static inline void __smp_reschedule_interrupt(void)
__visible void smp_reschedule_interrupt(struct pt_regs *regs)
{
+ irq_enter();
ack_APIC_irq();
__smp_reschedule_interrupt();
+ irq_exit();
/*
* KVM uses this interrupt to force a cpu out of guest mode
*/
--
1.9.1
next reply other threads:[~2016-10-14 1:49 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-10-14 1:48 Wanpeng Li [this message]
2016-10-14 12:19 ` [tip:x86/urgent] x86/smp: Add irq_enter/exit() in smp_reschedule_interrupt() tip-bot for Wanpeng Li
2016-10-16 13:39 ` [PATCH] " Peter Zijlstra
2016-10-17 4:19 ` Wanpeng Li
2016-10-17 8:22 ` Peter Zijlstra
2016-10-17 9:45 ` Wanpeng Li
2016-10-17 10:08 ` Paolo Bonzini
2016-10-17 10:23 ` Wanpeng Li
2016-10-18 0:01 ` Wanpeng Li
2016-10-19 14:01 ` Wanpeng Li
2016-10-19 14:10 ` Paolo Bonzini
2016-10-19 14:30 ` Wanpeng Li
2016-10-24 14:32 ` Paolo Bonzini
2016-10-25 2:52 ` Wanpeng Li
2016-10-17 12:19 ` Wanpeng Li
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1476409733-5133-1-git-send-email-wanpeng.li@hotmail.com \
--to=kernellwp@gmail.com \
--cc=efault@gmx.de \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@kernel.org \
--cc=peterz@infradead.org \
--cc=tglx@linutronix.de \
--cc=wanpeng.li@hotmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).