Re: [PATCH] rcu: Remove redundant rcu_is_cpu_rrupt_from_idle() function

2014-10-31 Thread Alexander Gordeev
On Thu, Oct 30, 2014 at 08:45:59PM -0700, Paul E. McKenney wrote: > On Thu, Oct 30, 2014 at 09:54:34PM +, Alexander Gordeev wrote: > > On Thu, Oct 30, 2014 at 01:43:18PM -0700, Paul E. McKenney wrote: > > > > > Have you done any testing of this change? > > > > > > > > Just booted to a unicore

Re: [PATCH] rcu: Remove redundant rcu_is_cpu_rrupt_from_idle() function

2014-10-31 Thread Alexander Gordeev
On Thu, Oct 30, 2014 at 08:45:59PM -0700, Paul E. McKenney wrote: On Thu, Oct 30, 2014 at 09:54:34PM +, Alexander Gordeev wrote: On Thu, Oct 30, 2014 at 01:43:18PM -0700, Paul E. McKenney wrote: Have you done any testing of this change? Just booted to a unicore kernel and

Re: [PATCH] rcu: Remove redundant rcu_is_cpu_rrupt_from_idle() function

2014-10-30 Thread Paul E. McKenney
On Thu, Oct 30, 2014 at 09:54:34PM +, Alexander Gordeev wrote: > On Thu, Oct 30, 2014 at 01:43:18PM -0700, Paul E. McKenney wrote: > > > > Have you done any testing of this change? > > > > > > Just booted to a unicore kernel and dd'ed 1G of /dev/sda to /dev/null. > > > > OK, that is a start.

Re: [PATCH] rcu: Remove redundant rcu_is_cpu_rrupt_from_idle() function

2014-10-30 Thread Alexander Gordeev
On Thu, Oct 30, 2014 at 01:43:18PM -0700, Paul E. McKenney wrote: > > > Have you done any testing of this change? > > > > Just booted to a unicore kernel and dd'ed 1G of /dev/sda to /dev/null. > > OK, that is a start. Could I convince you to build a kernel? I did build one with the patch I

Re: [PATCH] rcu: Remove redundant rcu_is_cpu_rrupt_from_idle() function

2014-10-30 Thread Paul E. McKenney
On Thu, Oct 30, 2014 at 05:54:35PM +, Alexander Gordeev wrote: > On Wed, Oct 29, 2014 at 05:05:24PM -0700, Paul E. McKenney wrote: > > > > Although it is true that tiny RCU cannot hang a synchronize_rcu() > > > > grace period, it most certainly can hang a call_rcu() grace period > > > > in

Re: [PATCH] rcu: Remove redundant rcu_is_cpu_rrupt_from_idle() function

2014-10-30 Thread Alexander Gordeev
On Wed, Oct 29, 2014 at 05:05:24PM -0700, Paul E. McKenney wrote: > > > Although it is true that tiny RCU cannot hang a synchronize_rcu() > > > grace period, it most certainly can hang a call_rcu() grace period > > > in exactly the same way. > > > > Sorry for being a pain in the neck - just want

Re: [PATCH] rcu: Remove redundant rcu_is_cpu_rrupt_from_idle() function

2014-10-30 Thread Alexander Gordeev
On Wed, Oct 29, 2014 at 05:05:24PM -0700, Paul E. McKenney wrote: Although it is true that tiny RCU cannot hang a synchronize_rcu() grace period, it most certainly can hang a call_rcu() grace period in exactly the same way. Sorry for being a pain in the neck - just want to make sure

Re: [PATCH] rcu: Remove redundant rcu_is_cpu_rrupt_from_idle() function

2014-10-30 Thread Paul E. McKenney
On Thu, Oct 30, 2014 at 05:54:35PM +, Alexander Gordeev wrote: On Wed, Oct 29, 2014 at 05:05:24PM -0700, Paul E. McKenney wrote: Although it is true that tiny RCU cannot hang a synchronize_rcu() grace period, it most certainly can hang a call_rcu() grace period in exactly the same

Re: [PATCH] rcu: Remove redundant rcu_is_cpu_rrupt_from_idle() function

2014-10-30 Thread Alexander Gordeev
On Thu, Oct 30, 2014 at 01:43:18PM -0700, Paul E. McKenney wrote: Have you done any testing of this change? Just booted to a unicore kernel and dd'ed 1G of /dev/sda to /dev/null. OK, that is a start. Could I convince you to build a kernel? I did build one with the patch I posted. Or

Re: [PATCH] rcu: Remove redundant rcu_is_cpu_rrupt_from_idle() function

2014-10-30 Thread Paul E. McKenney
On Thu, Oct 30, 2014 at 09:54:34PM +, Alexander Gordeev wrote: On Thu, Oct 30, 2014 at 01:43:18PM -0700, Paul E. McKenney wrote: Have you done any testing of this change? Just booted to a unicore kernel and dd'ed 1G of /dev/sda to /dev/null. OK, that is a start. Could I

Re: [PATCH] rcu: Remove redundant rcu_is_cpu_rrupt_from_idle() function

2014-10-29 Thread Paul E. McKenney
On Wed, Oct 29, 2014 at 09:09:16PM +, Alexander Gordeev wrote: > On Wed, Oct 29, 2014 at 08:46:15AM -0700, Paul E. McKenney wrote: > > On Wed, Oct 29, 2014 at 03:16:23PM +, Alexander Gordeev wrote: > > > On Wed, Oct 29, 2014 at 07:34:39AM -0700, Paul E. McKenney wrote: > > > > On Wed, Oct

Re: [PATCH] rcu: Remove redundant rcu_is_cpu_rrupt_from_idle() function

2014-10-29 Thread Alexander Gordeev
On Wed, Oct 29, 2014 at 08:46:15AM -0700, Paul E. McKenney wrote: > On Wed, Oct 29, 2014 at 03:16:23PM +, Alexander Gordeev wrote: > > On Wed, Oct 29, 2014 at 07:34:39AM -0700, Paul E. McKenney wrote: > > > On Wed, Oct 29, 2014 at 01:45:19PM +, Alexander Gordeev wrote: > > > > On Wed, Oct

Re: [PATCH] rcu: Remove redundant rcu_is_cpu_rrupt_from_idle() function

2014-10-29 Thread Paul E. McKenney
On Wed, Oct 29, 2014 at 03:16:23PM +, Alexander Gordeev wrote: > On Wed, Oct 29, 2014 at 07:34:39AM -0700, Paul E. McKenney wrote: > > On Wed, Oct 29, 2014 at 01:45:19PM +, Alexander Gordeev wrote: > > > On Wed, Oct 29, 2014 at 05:47:29AM -0700, Paul E. McKenney wrote: > > > > On Wed, Oct

Re: [PATCH] rcu: Remove redundant rcu_is_cpu_rrupt_from_idle() function

2014-10-29 Thread Alexander Gordeev
On Wed, Oct 29, 2014 at 07:34:39AM -0700, Paul E. McKenney wrote: > On Wed, Oct 29, 2014 at 01:45:19PM +, Alexander Gordeev wrote: > > On Wed, Oct 29, 2014 at 05:47:29AM -0700, Paul E. McKenney wrote: > > > On Wed, Oct 29, 2014 at 12:07:07PM +0100, Alexander Gordeev wrote: > > > > Function

Re: [PATCH] rcu: Remove redundant rcu_is_cpu_rrupt_from_idle() function

2014-10-29 Thread Paul E. McKenney
On Wed, Oct 29, 2014 at 01:45:19PM +, Alexander Gordeev wrote: > On Wed, Oct 29, 2014 at 05:47:29AM -0700, Paul E. McKenney wrote: > > On Wed, Oct 29, 2014 at 12:07:07PM +0100, Alexander Gordeev wrote: > > > Function rcu_is_cpu_rrupt_from_idle() is called from scheduling- > > > clock interrupt

Re: [PATCH] rcu: Remove redundant rcu_is_cpu_rrupt_from_idle() function

2014-10-29 Thread Alexander Gordeev
On Wed, Oct 29, 2014 at 05:47:29AM -0700, Paul E. McKenney wrote: > On Wed, Oct 29, 2014 at 12:07:07PM +0100, Alexander Gordeev wrote: > > Function rcu_is_cpu_rrupt_from_idle() is called from scheduling- > > clock interrupt handler to check if the current CPU was interrupted > > from idle. If

Re: [PATCH] rcu: Remove redundant rcu_is_cpu_rrupt_from_idle() function

2014-10-29 Thread Paul E. McKenney
On Wed, Oct 29, 2014 at 12:07:07PM +0100, Alexander Gordeev wrote: > Function rcu_is_cpu_rrupt_from_idle() is called from scheduling- > clock interrupt handler to check if the current CPU was interrupted > from idle. If true, it results in invocation of RCU callbacks. But > the common hardware

[PATCH] rcu: Remove redundant rcu_is_cpu_rrupt_from_idle() function

2014-10-29 Thread Alexander Gordeev
Function rcu_is_cpu_rrupt_from_idle() is called from scheduling- clock interrupt handler to check if the current CPU was interrupted from idle. If true, it results in invocation of RCU callbacks. But the common hardware interrupt exit path also contains similar check and therefore the call to

[PATCH] rcu: Remove redundant rcu_is_cpu_rrupt_from_idle() function

2014-10-29 Thread Alexander Gordeev
Function rcu_is_cpu_rrupt_from_idle() is called from scheduling- clock interrupt handler to check if the current CPU was interrupted from idle. If true, it results in invocation of RCU callbacks. But the common hardware interrupt exit path also contains similar check and therefore the call to

Re: [PATCH] rcu: Remove redundant rcu_is_cpu_rrupt_from_idle() function

2014-10-29 Thread Paul E. McKenney
On Wed, Oct 29, 2014 at 12:07:07PM +0100, Alexander Gordeev wrote: Function rcu_is_cpu_rrupt_from_idle() is called from scheduling- clock interrupt handler to check if the current CPU was interrupted from idle. If true, it results in invocation of RCU callbacks. But the common hardware

Re: [PATCH] rcu: Remove redundant rcu_is_cpu_rrupt_from_idle() function

2014-10-29 Thread Alexander Gordeev
On Wed, Oct 29, 2014 at 05:47:29AM -0700, Paul E. McKenney wrote: On Wed, Oct 29, 2014 at 12:07:07PM +0100, Alexander Gordeev wrote: Function rcu_is_cpu_rrupt_from_idle() is called from scheduling- clock interrupt handler to check if the current CPU was interrupted from idle. If true, it

Re: [PATCH] rcu: Remove redundant rcu_is_cpu_rrupt_from_idle() function

2014-10-29 Thread Paul E. McKenney
On Wed, Oct 29, 2014 at 01:45:19PM +, Alexander Gordeev wrote: On Wed, Oct 29, 2014 at 05:47:29AM -0700, Paul E. McKenney wrote: On Wed, Oct 29, 2014 at 12:07:07PM +0100, Alexander Gordeev wrote: Function rcu_is_cpu_rrupt_from_idle() is called from scheduling- clock interrupt handler

Re: [PATCH] rcu: Remove redundant rcu_is_cpu_rrupt_from_idle() function

2014-10-29 Thread Alexander Gordeev
On Wed, Oct 29, 2014 at 07:34:39AM -0700, Paul E. McKenney wrote: On Wed, Oct 29, 2014 at 01:45:19PM +, Alexander Gordeev wrote: On Wed, Oct 29, 2014 at 05:47:29AM -0700, Paul E. McKenney wrote: On Wed, Oct 29, 2014 at 12:07:07PM +0100, Alexander Gordeev wrote: Function

Re: [PATCH] rcu: Remove redundant rcu_is_cpu_rrupt_from_idle() function

2014-10-29 Thread Paul E. McKenney
On Wed, Oct 29, 2014 at 03:16:23PM +, Alexander Gordeev wrote: On Wed, Oct 29, 2014 at 07:34:39AM -0700, Paul E. McKenney wrote: On Wed, Oct 29, 2014 at 01:45:19PM +, Alexander Gordeev wrote: On Wed, Oct 29, 2014 at 05:47:29AM -0700, Paul E. McKenney wrote: On Wed, Oct 29, 2014

Re: [PATCH] rcu: Remove redundant rcu_is_cpu_rrupt_from_idle() function

2014-10-29 Thread Alexander Gordeev
On Wed, Oct 29, 2014 at 08:46:15AM -0700, Paul E. McKenney wrote: On Wed, Oct 29, 2014 at 03:16:23PM +, Alexander Gordeev wrote: On Wed, Oct 29, 2014 at 07:34:39AM -0700, Paul E. McKenney wrote: On Wed, Oct 29, 2014 at 01:45:19PM +, Alexander Gordeev wrote: On Wed, Oct 29, 2014

Re: [PATCH] rcu: Remove redundant rcu_is_cpu_rrupt_from_idle() function

2014-10-29 Thread Paul E. McKenney
On Wed, Oct 29, 2014 at 09:09:16PM +, Alexander Gordeev wrote: On Wed, Oct 29, 2014 at 08:46:15AM -0700, Paul E. McKenney wrote: On Wed, Oct 29, 2014 at 03:16:23PM +, Alexander Gordeev wrote: On Wed, Oct 29, 2014 at 07:34:39AM -0700, Paul E. McKenney wrote: On Wed, Oct 29, 2014