Re: [PATCH 1/3] x86/sched/context_tracking: Call new schedule_preempt_user() from entry_64.S

2013-05-14 Thread Li Zhong
On Tue, 2013-05-14 at 16:13 +0200, Frederic Weisbecker wrote: > On Fri, May 10, 2013 at 05:12:26PM -0400, Steven Rostedt wrote: > > +/* > > + * This is a entry point to the scheduler() just before going > > + * back to user space. This is called with irqs disabled > > + * which prevents races with

Re: [PATCH 1/3] x86/sched/context_tracking: Call new schedule_preempt_user() from entry_64.S

2013-05-14 Thread Frederic Weisbecker
On Fri, May 10, 2013 at 05:12:26PM -0400, Steven Rostedt wrote: > +/* > + * This is a entry point to the scheduler() just before going > + * back to user space. This is called with irqs disabled > + * which prevents races with the CONTEXT_TRACKING updates. > + */ > +asmlinkage void __sched schedule

Re: [PATCH 1/3] x86/sched/context_tracking: Call new schedule_preempt_user() from entry_64.S

2013-05-14 Thread Li Zhong
On Mon, 2013-05-13 at 11:03 -0400, Steven Rostedt wrote: > On Mon, 2013-05-13 at 17:56 +0800, Li Zhong wrote: > > > > All this before schedule_user() was able to call user_exit() and take us > > > out of dynamic tick user context. > > > > Maybe we could just disable function trace for schedule_us

Re: [PATCH 1/3] x86/sched/context_tracking: Call new schedule_preempt_user() from entry_64.S

2013-05-13 Thread Steven Rostedt
On Mon, 2013-05-13 at 17:56 +0800, Li Zhong wrote: > > All this before schedule_user() was able to call user_exit() and take us > > out of dynamic tick user context. > > Maybe we could just disable function trace for schedule_user()? > > It seems that function trace might use RCU, at least in _

Re: [PATCH 1/3] x86/sched/context_tracking: Call new schedule_preempt_user() from entry_64.S

2013-05-13 Thread Li Zhong
On Fri, 2013-05-10 at 17:12 -0400, Steven Rostedt wrote: > plain text document attachment (fix-user-exit-preempt.patch) > I started testing the new NOHZ_FULL in the kernel and had some issues, > so I started function tracing and this bug report came out: > > > [23446.458073] [ cut her

Re: [PATCH 1/3] x86/sched/context_tracking: Call new schedule_preempt_user() from entry_64.S

2013-05-10 Thread Frederic Weisbecker
On Fri, May 10, 2013 at 05:12:26PM -0400, Steven Rostedt wrote: > +/* > + * This is a entry point to the scheduler() just before going > + * back to user space. This is called with irqs disabled > + * which prevents races with the CONTEXT_TRACKING updates. > + */ > +asmlinkage void __sched schedule

[PATCH 1/3] x86/sched/context_tracking: Call new schedule_preempt_user() from entry_64.S

2013-05-10 Thread Steven Rostedt
I started testing the new NOHZ_FULL in the kernel and had some issues, so I started function tracing and this bug report came out: [23446.458073] [ cut here ] [23446.461028] WARNING: at /home/rostedt/work/git/linux-trace.git/kernel/rcutree.c:388 rcu_eqs_enter+0x4b/0x89() [