Mojiong Qiu 772aebcefe 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>
2012-11-07 10:41:27 -05:00
..
2012-10-02 17:26:42 -07:00
2012-10-07 20:55:16 +09:00
2012-10-12 10:21:02 +09:00
2012-10-11 00:45:21 -07:00
2012-09-26 22:28:21 -04:00
2012-09-22 10:29:19 +01:00
2012-10-08 06:33:44 +09:00
2012-09-24 10:07:40 -07:00
2012-10-13 13:22:01 -07:00
2012-10-07 17:29:24 +09:00
2012-10-10 20:15:24 +09:00
2012-10-12 13:56:52 -04:00
2012-10-03 09:44:08 -07:00
2012-10-09 16:11:46 +09:00
2012-10-01 19:11:38 -07:00
2012-10-10 20:15:24 +09:00
2012-10-13 10:57:01 +09:00
2012-10-01 19:11:38 -07:00
2012-10-13 11:16:58 +09:00
2012-10-01 12:09:59 -07:00
2012-10-01 18:46:13 -07:00