Re: [patch 6/6] rtmutex: Avoid pointless requeueing in the deadlock detection chain walk

2014-05-30 Thread Steven Rostedt
On Wed, 28 May 2014 11:43:16 +0200 (CEST) Thomas Gleixner wrote: [snip] > > > > In the above case, could we go 1 step further and avoid taking the pi > > lock as well? [snip] > > Indeed. > > Are you going to repost this patch? I'd like to review that one instead of this one if you're

Re: [patch 6/6] rtmutex: Avoid pointless requeueing in the deadlock detection chain walk

2014-05-30 Thread Steven Rostedt
On Wed, 28 May 2014 11:43:16 +0200 (CEST) Thomas Gleixner t...@linutronix.de wrote: [snip] In the above case, could we go 1 step further and avoid taking the pi lock as well? [snip] Indeed. Are you going to repost this patch? I'd like to review that one instead of this one if

Re: [patch 6/6] rtmutex: Avoid pointless requeueing in the deadlock detection chain walk

2014-05-28 Thread Thomas Gleixner
On Tue, 27 May 2014, Jason Low wrote: > On Wed, May 21, 2014 at 8:25 PM, Thomas Gleixner wrote: > > > @@ -440,32 +452,41 @@ static int rt_mutex_adjust_prio_chain(st > > get_task_struct(task); > > raw_spin_lock_irqsave(>pi_lock, flags); > > > > - if (waiter ==

Re: [patch 6/6] rtmutex: Avoid pointless requeueing in the deadlock detection chain walk

2014-05-28 Thread Thomas Gleixner
On Tue, 27 May 2014, Jason Low wrote: On Wed, May 21, 2014 at 8:25 PM, Thomas Gleixner t...@linutronix.de wrote: @@ -440,32 +452,41 @@ static int rt_mutex_adjust_prio_chain(st get_task_struct(task); raw_spin_lock_irqsave(task-pi_lock, flags); - if (waiter ==

Re: [patch 6/6] rtmutex: Avoid pointless requeueing in the deadlock detection chain walk

2014-05-27 Thread Jason Low
On Wed, May 21, 2014 at 8:25 PM, Thomas Gleixner wrote: > @@ -440,32 +452,41 @@ static int rt_mutex_adjust_prio_chain(st > get_task_struct(task); > raw_spin_lock_irqsave(>pi_lock, flags); > > - if (waiter == rt_mutex_top_waiter(lock)) { > - /* > -

Re: [patch 6/6] rtmutex: Avoid pointless requeueing in the deadlock detection chain walk

2014-05-27 Thread Jason Low
On Wed, May 21, 2014 at 8:25 PM, Thomas Gleixner t...@linutronix.de wrote: @@ -440,32 +452,41 @@ static int rt_mutex_adjust_prio_chain(st get_task_struct(task); raw_spin_lock_irqsave(task-pi_lock, flags); - if (waiter == rt_mutex_top_waiter(lock)) { - /*

[patch 6/6] rtmutex: Avoid pointless requeueing in the deadlock detection chain walk

2014-05-21 Thread Thomas Gleixner
In case the dead lock detector is enabled we follow the lock chain to the end in rt_mutex_adjust_prio_chain, even if we could stop earlier due to the priority/waiter constellation. But once we are not longer the top priority waiter in a certain step or the task holding the lock has already the

[patch 6/6] rtmutex: Avoid pointless requeueing in the deadlock detection chain walk

2014-05-21 Thread Thomas Gleixner
In case the dead lock detector is enabled we follow the lock chain to the end in rt_mutex_adjust_prio_chain, even if we could stop earlier due to the priority/waiter constellation. But once we are not longer the top priority waiter in a certain step or the task holding the lock has already the