* [PATCH] xen/events: xen/events: fix RCU warning
@ 2012-11-06 8:08 Mojiong Qiu
0 siblings, 0 replies; 3+ messages in thread
From: Mojiong Qiu @ 2012-11-06 8:08 UTC (permalink / raw)
To: linux-kernel
Cc: Jeremy Fitzhardinge, xen-devel, Konrad Rzeszutek Wilk,
Mojiong Qiu, Mojiong Qiu, virtualization, at least to 3.0.y
exit_idle() should be called after irq_enter(), otherwise it throws:
[ 2.513020] [ INFO: suspicious RCU usage. ]
[ 2.513076] 3.6.5 #1 Not tainted
[ 2.513128] -------------------------------
[ 2.513183] include/linux/rcupdate.h:725 rcu_read_lock() used illegally while idle!
[ 2.513271]
[ 2.513271] other info that might help us debug this:
[ 2.513271]
[ 2.513388]
[ 2.513388] RCU used illegally from idle CPU!
[ 2.513388] rcu_scheduler_active = 1, debug_locks = 1
[ 2.513511] RCU used illegally from extended quiescent state!
[ 2.513572] 1 lock held by swapper/0/0:
[ 2.513626] #0: (rcu_read_lock){......}, at: [<ffffffff810e9fe0>] __atomic_notifier_call_chain+0x0/0x140
[ 2.513815]
[ 2.513815] stack backtrace:
[ 2.513897] Pid: 0, comm: swapper/0 Not tainted 3.6.5 #1
[ 2.513954] Call Trace:
[ 2.514005] <IRQ> [<ffffffff811259a2>] lockdep_rcu_suspicious+0xe2/0x130
[ 2.514107] [<ffffffff810ea10c>] __atomic_notifier_call_chain+0x12c/0x140
[ 2.514169] [<ffffffff810e9fe0>] ? atomic_notifier_chain_unregister+0x90/0x90
[ 2.514258] [<ffffffff811216cd>] ? trace_hardirqs_off+0xd/0x10
[ 2.514318] [<ffffffff810ea136>] atomic_notifier_call_chain+0x16/0x20
[ 2.514381] [<ffffffff810777c3>] exit_idle+0x43/0x50
[ 2.514441] [<ffffffff81568865>] xen_evtchn_do_upcall+0x25/0x50
[ 2.514503] [<ffffffff81aa690e>] xen_do_hypervisor_callback+0x1e/0x30
[ 2.514562] <EOI> [<ffffffff810013aa>] ? hypercall_page+0x3aa/0x1000
[ 2.514662] [<ffffffff810013aa>] ? hypercall_page+0x3aa/0x1000
[ 2.514722] [<ffffffff81061540>] ? xen_safe_halt+0x10/0x20
[ 2.514782] [<ffffffff81075cfa>] ? default_idle+0xba/0x570
[ 2.514841] [<ffffffff810778af>] ? cpu_idle+0xdf/0x140
[ 2.514900] [<ffffffff81a4d881>] ? rest_init+0x135/0x144
[ 2.514960] [<ffffffff81a4d74c>] ? csum_partial_copy_generic+0x16c/0x16c
[ 2.515022] [<ffffffff82520c45>] ? start_kernel+0x3db/0x3e8
[ 2.515081] [<ffffffff8252066a>] ? repair_env_string+0x5a/0x5a
[ 2.515141] [<ffffffff82520356>] ? x86_64_start_reservations+0x131/0x135
[ 2.515202] [<ffffffff82524aca>] ? xen_start_kernel+0x465/0x46
Signed-off-by: Mojiong Qiu <mjqiu@tencent.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: xen-devel@lists.xensource.com
Cc: virtualization@lists.linux-foundation.org
Cc: linux-kernel@vger.kernel.org
Cc: stable@kernel.org (at least to 3.0.y)
---
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 912ac81..0be4df3 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();
--
1.6.3.2
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] xen/events: xen/events: fix RCU warning
[not found] <1352189295-7111-1-git-send-email-qiumojiong@gmail.com>
@ 2012-11-06 16:17 ` Konrad Rzeszutek Wilk
2012-11-07 8:03 ` 邱模炯
0 siblings, 1 reply; 3+ messages in thread
From: Konrad Rzeszutek Wilk @ 2012-11-06 16:17 UTC (permalink / raw)
To: Mojiong Qiu
Cc: Jeremy Fitzhardinge, xen-devel, Mojiong Qiu, linux-kernel,
virtualization, at least to 3.0.y
On Tue, Nov 06, 2012 at 04:08:15PM +0800, Mojiong Qiu wrote:
> exit_idle() should be called after irq_enter(), otherwise it throws:
That seems odd - wouldn't "smp_x86_platform_ipi"
also need the same treatment [edit: I was looking at 3.0 kernel code] ?
Ah, this is caused by
commit 98ad1cc14a5c4fd658f9d72c6ba5c86dfd3ce0d5
Author: Frederic Weisbecker <fweisbec@gmail.com>
Date: Fri Oct 7 18:22:09 2011 +0200
x86: Call idle notifier after irq_enter()
and it missed the xen-case
which means that any kernel v3.3 and newer need this, but earlier do
not.
Thx. Will put in 3.7 tree.
>
> [ 2.513020] [ INFO: suspicious RCU usage. ]
> [ 2.513076] 3.6.5 #1 Not tainted
> [ 2.513128] -------------------------------
> [ 2.513183] include/linux/rcupdate.h:725 rcu_read_lock() used illegally while idle!
> [ 2.513271]
> [ 2.513271] other info that might help us debug this:
> [ 2.513271]
> [ 2.513388]
> [ 2.513388] RCU used illegally from idle CPU!
> [ 2.513388] rcu_scheduler_active = 1, debug_locks = 1
> [ 2.513511] RCU used illegally from extended quiescent state!
> [ 2.513572] 1 lock held by swapper/0/0:
> [ 2.513626] #0: (rcu_read_lock){......}, at: [<ffffffff810e9fe0>] __atomic_notifier_call_chain+0x0/0x140
> [ 2.513815]
> [ 2.513815] stack backtrace:
> [ 2.513897] Pid: 0, comm: swapper/0 Not tainted 3.6.5 #1
> [ 2.513954] Call Trace:
> [ 2.514005] <IRQ> [<ffffffff811259a2>] lockdep_rcu_suspicious+0xe2/0x130
> [ 2.514107] [<ffffffff810ea10c>] __atomic_notifier_call_chain+0x12c/0x140
> [ 2.514169] [<ffffffff810e9fe0>] ? atomic_notifier_chain_unregister+0x90/0x90
> [ 2.514258] [<ffffffff811216cd>] ? trace_hardirqs_off+0xd/0x10
> [ 2.514318] [<ffffffff810ea136>] atomic_notifier_call_chain+0x16/0x20
> [ 2.514381] [<ffffffff810777c3>] exit_idle+0x43/0x50
> [ 2.514441] [<ffffffff81568865>] xen_evtchn_do_upcall+0x25/0x50
> [ 2.514503] [<ffffffff81aa690e>] xen_do_hypervisor_callback+0x1e/0x30
> [ 2.514562] <EOI> [<ffffffff810013aa>] ? hypercall_page+0x3aa/0x1000
> [ 2.514662] [<ffffffff810013aa>] ? hypercall_page+0x3aa/0x1000
> [ 2.514722] [<ffffffff81061540>] ? xen_safe_halt+0x10/0x20
> [ 2.514782] [<ffffffff81075cfa>] ? default_idle+0xba/0x570
> [ 2.514841] [<ffffffff810778af>] ? cpu_idle+0xdf/0x140
> [ 2.514900] [<ffffffff81a4d881>] ? rest_init+0x135/0x144
> [ 2.514960] [<ffffffff81a4d74c>] ? csum_partial_copy_generic+0x16c/0x16c
> [ 2.515022] [<ffffffff82520c45>] ? start_kernel+0x3db/0x3e8
> [ 2.515081] [<ffffffff8252066a>] ? repair_env_string+0x5a/0x5a
> [ 2.515141] [<ffffffff82520356>] ? x86_64_start_reservations+0x131/0x135
> [ 2.515202] [<ffffffff82524aca>] ? xen_start_kernel+0x465/0x46
>
> Signed-off-by: Mojiong Qiu <mjqiu@tencent.com>
> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
> Cc: Jeremy Fitzhardinge <jeremy@goop.org>
> Cc: xen-devel@lists.xensource.com
> Cc: virtualization@lists.linux-foundation.org
> Cc: linux-kernel@vger.kernel.org
> Cc: stable@kernel.org (at least to 3.0.y)
^^^- vger.kernel.org
You mean 3.3.x
> ---
> 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 912ac81..0be4df3 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();
>
> --
> 1.6.3.2
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] xen/events: xen/events: fix RCU warning
2012-11-06 16:17 ` [PATCH] xen/events: xen/events: fix RCU warning Konrad Rzeszutek Wilk
@ 2012-11-07 8:03 ` 邱模炯
0 siblings, 0 replies; 3+ messages in thread
From: 邱模炯 @ 2012-11-07 8:03 UTC (permalink / raw)
To: Konrad Rzeszutek Wilk
Cc: Jeremy Fitzhardinge, xen-devel, Mojiong Qiu, linux-kernel,
virtualization, at least to 3.0.y
Thanks Konrad. You are right, commit 98ad1cc14 missed the xen case.
And before merging, please modify the title a bit. one redundant
"xen/events" there.
"xen/events: xen/events: fix RCU warning" -> "xen/events: fix RCU warning"
>> Cc: stable@kernel.org (at least to 3.0.y)
> ^^^- vger.kernel.org
>
> You mean 3.3.x
This is my mistake. 3.0.y is OK. please ignore it.
On Wed, Nov 7, 2012 at 12:17 AM, Konrad Rzeszutek Wilk
<konrad.wilk@oracle.com> wrote:
> On Tue, Nov 06, 2012 at 04:08:15PM +0800, Mojiong Qiu wrote:
>> exit_idle() should be called after irq_enter(), otherwise it throws:
>
> That seems odd - wouldn't "smp_x86_platform_ipi"
> also need the same treatment [edit: I was looking at 3.0 kernel code] ?
>
> Ah, this is caused by
>
> commit 98ad1cc14a5c4fd658f9d72c6ba5c86dfd3ce0d5
> Author: Frederic Weisbecker <fweisbec@gmail.com>
> Date: Fri Oct 7 18:22:09 2011 +0200
>
> x86: Call idle notifier after irq_enter()
>
>
> and it missed the xen-case
>
> which means that any kernel v3.3 and newer need this, but earlier do
> not.
>
> Thx. Will put in 3.7 tree.
>
>>
>> [ 2.513020] [ INFO: suspicious RCU usage. ]
>> [ 2.513076] 3.6.5 #1 Not tainted
>> [ 2.513128] -------------------------------
>> [ 2.513183] include/linux/rcupdate.h:725 rcu_read_lock() used illegally while idle!
>> [ 2.513271]
>> [ 2.513271] other info that might help us debug this:
>> [ 2.513271]
>> [ 2.513388]
>> [ 2.513388] RCU used illegally from idle CPU!
>> [ 2.513388] rcu_scheduler_active = 1, debug_locks = 1
>> [ 2.513511] RCU used illegally from extended quiescent state!
>> [ 2.513572] 1 lock held by swapper/0/0:
>> [ 2.513626] #0: (rcu_read_lock){......}, at: [<ffffffff810e9fe0>] __atomic_notifier_call_chain+0x0/0x140
>> [ 2.513815]
>> [ 2.513815] stack backtrace:
>> [ 2.513897] Pid: 0, comm: swapper/0 Not tainted 3.6.5 #1
>> [ 2.513954] Call Trace:
>> [ 2.514005] <IRQ> [<ffffffff811259a2>] lockdep_rcu_suspicious+0xe2/0x130
>> [ 2.514107] [<ffffffff810ea10c>] __atomic_notifier_call_chain+0x12c/0x140
>> [ 2.514169] [<ffffffff810e9fe0>] ? atomic_notifier_chain_unregister+0x90/0x90
>> [ 2.514258] [<ffffffff811216cd>] ? trace_hardirqs_off+0xd/0x10
>> [ 2.514318] [<ffffffff810ea136>] atomic_notifier_call_chain+0x16/0x20
>> [ 2.514381] [<ffffffff810777c3>] exit_idle+0x43/0x50
>> [ 2.514441] [<ffffffff81568865>] xen_evtchn_do_upcall+0x25/0x50
>> [ 2.514503] [<ffffffff81aa690e>] xen_do_hypervisor_callback+0x1e/0x30
>> [ 2.514562] <EOI> [<ffffffff810013aa>] ? hypercall_page+0x3aa/0x1000
>> [ 2.514662] [<ffffffff810013aa>] ? hypercall_page+0x3aa/0x1000
>> [ 2.514722] [<ffffffff81061540>] ? xen_safe_halt+0x10/0x20
>> [ 2.514782] [<ffffffff81075cfa>] ? default_idle+0xba/0x570
>> [ 2.514841] [<ffffffff810778af>] ? cpu_idle+0xdf/0x140
>> [ 2.514900] [<ffffffff81a4d881>] ? rest_init+0x135/0x144
>> [ 2.514960] [<ffffffff81a4d74c>] ? csum_partial_copy_generic+0x16c/0x16c
>> [ 2.515022] [<ffffffff82520c45>] ? start_kernel+0x3db/0x3e8
>> [ 2.515081] [<ffffffff8252066a>] ? repair_env_string+0x5a/0x5a
>> [ 2.515141] [<ffffffff82520356>] ? x86_64_start_reservations+0x131/0x135
>> [ 2.515202] [<ffffffff82524aca>] ? xen_start_kernel+0x465/0x46
>>
>> Signed-off-by: Mojiong Qiu <mjqiu@tencent.com>
>> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
>> Cc: Jeremy Fitzhardinge <jeremy@goop.org>
>> Cc: xen-devel@lists.xensource.com
>> Cc: virtualization@lists.linux-foundation.org
>> Cc: linux-kernel@vger.kernel.org
>> Cc: stable@kernel.org (at least to 3.0.y)
> ^^^- vger.kernel.org
>
> You mean 3.3.x
>
>> ---
>> 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 912ac81..0be4df3 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();
>>
>> --
>> 1.6.3.2
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2012-11-07 8:03 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
[not found] <1352189295-7111-1-git-send-email-qiumojiong@gmail.com>
2012-11-06 16:17 ` [PATCH] xen/events: xen/events: fix RCU warning Konrad Rzeszutek Wilk
2012-11-07 8:03 ` 邱模炯
2012-11-06 8:08 Mojiong Qiu
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).