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| author | Mojiong Qiu <qiumojiong@gmail.com> | 2012-11-06 16:08:15 +0800 |
|---|---|---|
| committer | Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> | 2012-11-07 10:41:27 -0500 |
| commit | 772aebcefeff310f80e32b874988af0076cb799d (patch) | |
| tree | 5e3e899b8b67a7905813360dc82302907eb65783 | |
| parent | 6d877e6b85691e0b2b22e90aeb9b86c3dafcfc6b (diff) | |
| download | linux-772aebcefeff310f80e32b874988af0076cb799d.tar.gz linux-772aebcefeff310f80e32b874988af0076cb799d.tar.bz2 linux-772aebcefeff310f80e32b874988af0076cb799d.zip | |
xen/events: fix RCU warning, or Call idle notifier after irq_enter()
exit_idle() should be called after irq_enter(), otherwise it throws:
[ INFO: suspicious RCU usage. ]
3.6.5 #1 Not tainted
-------------------------------
include/linux/rcupdate.h:725 rcu_read_lock() used illegally while idle!
other info that might help us debug this:
RCU used illegally from idle CPU!
rcu_scheduler_active = 1, debug_locks = 1
RCU used illegally from extended quiescent state!
1 lock held by swapper/0/0:
#0: (rcu_read_lock){......}, at: [<ffffffff810e9fe0>] __atomic_notifier_call_chain+0x0/0x140
stack backtrace:
Pid: 0, comm: swapper/0 Not tainted 3.6.5 #1
Call Trace:
<IRQ> [<ffffffff811259a2>] lockdep_rcu_suspicious+0xe2/0x130
[<ffffffff810ea10c>] __atomic_notifier_call_chain+0x12c/0x140
[<ffffffff810e9fe0>] ? atomic_notifier_chain_unregister+0x90/0x90
[<ffffffff811216cd>] ? trace_hardirqs_off+0xd/0x10
[<ffffffff810ea136>] atomic_notifier_call_chain+0x16/0x20
[<ffffffff810777c3>] exit_idle+0x43/0x50
[<ffffffff81568865>] xen_evtchn_do_upcall+0x25/0x50
[<ffffffff81aa690e>] xen_do_hypervisor_callback+0x1e/0x30
<EOI> [<ffffffff810013aa>] ? hypercall_page+0x3aa/0x1000
[<ffffffff810013aa>] ? hypercall_page+0x3aa/0x1000
[<ffffffff81061540>] ? xen_safe_halt+0x10/0x20
[<ffffffff81075cfa>] ? default_idle+0xba/0x570
[<ffffffff810778af>] ? cpu_idle+0xdf/0x140
[<ffffffff81a4d881>] ? rest_init+0x135/0x144
[<ffffffff81a4d74c>] ? csum_partial_copy_generic+0x16c/0x16c
[<ffffffff82520c45>] ? start_kernel+0x3db/0x3e8
[<ffffffff8252066a>] ? repair_env_string+0x5a/0x5a
[<ffffffff82520356>] ? x86_64_start_reservations+0x131/0x135
[<ffffffff82524aca>] ? xen_start_kernel+0x465/0x46
Git commit 98ad1cc14a5c4fd658f9d72c6ba5c86dfd3ce0d5
Author: Frederic Weisbecker <fweisbec@gmail.com>
Date: Fri Oct 7 18:22:09 2011 +0200
x86: Call idle notifier after irq_enter()
did this, but it missed the Xen code.
Signed-off-by: Mojiong Qiu <mjqiu@tencent.com>
Cc: stable@vger.kernel.org # from 3.3 and newer.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
| -rw-r--r-- | drivers/xen/events.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/xen/events.c b/drivers/xen/events.c index 912ac81b6dbf..0be4df39e953 100644 --- a/drivers/xen/events.c +++ b/drivers/xen/events.c @@ -1395,10 +1395,10 @@ void xen_evtchn_do_upcall(struct pt_regs *regs) { struct pt_regs *old_regs = set_irq_regs(regs); + irq_enter(); #ifdef CONFIG_X86 exit_idle(); #endif - irq_enter(); __xen_evtchn_do_upcall(); |