Re: [PATCH 6/7] cputime: Introduce vtime accounting check for readers

2015-11-23 Thread Frederic Weisbecker
On Mon, Nov 23, 2015 at 03:35:16PM +0100, Peter Zijlstra wrote: > On Mon, Nov 23, 2015 at 03:19:19PM +0100, Frederic Weisbecker wrote: > > On Thu, Nov 19, 2015 at 09:28:28PM +0100, Peter Zijlstra wrote: > > > On Thu, Nov 19, 2015 at 04:47:33PM +0100, Frederic Weisbecker wrote: > > > > +++

Re: [PATCH 6/7] cputime: Introduce vtime accounting check for readers

2015-11-23 Thread Peter Zijlstra
On Mon, Nov 23, 2015 at 03:19:19PM +0100, Frederic Weisbecker wrote: > On Thu, Nov 19, 2015 at 09:28:28PM +0100, Peter Zijlstra wrote: > > On Thu, Nov 19, 2015 at 04:47:33PM +0100, Frederic Weisbecker wrote: > > > +++ b/include/linux/vtime.h > > > @@ -17,9 +17,20 @@ static inline bool

Re: [PATCH 6/7] cputime: Introduce vtime accounting check for readers

2015-11-23 Thread Frederic Weisbecker
On Thu, Nov 19, 2015 at 09:28:28PM +0100, Peter Zijlstra wrote: > On Thu, Nov 19, 2015 at 04:47:33PM +0100, Frederic Weisbecker wrote: > > +++ b/include/linux/vtime.h > > @@ -17,9 +17,20 @@ static inline bool vtime_accounting_cpu_enabled(void) { > > return true; } > > #endif /*

Re: [PATCH 6/7] cputime: Introduce vtime accounting check for readers

2015-11-23 Thread Frederic Weisbecker
On Thu, Nov 19, 2015 at 09:28:28PM +0100, Peter Zijlstra wrote: > On Thu, Nov 19, 2015 at 04:47:33PM +0100, Frederic Weisbecker wrote: > > +++ b/include/linux/vtime.h > > @@ -17,9 +17,20 @@ static inline bool vtime_accounting_cpu_enabled(void) { > > return true; } > > #endif /*

Re: [PATCH 6/7] cputime: Introduce vtime accounting check for readers

2015-11-23 Thread Peter Zijlstra
On Mon, Nov 23, 2015 at 03:19:19PM +0100, Frederic Weisbecker wrote: > On Thu, Nov 19, 2015 at 09:28:28PM +0100, Peter Zijlstra wrote: > > On Thu, Nov 19, 2015 at 04:47:33PM +0100, Frederic Weisbecker wrote: > > > +++ b/include/linux/vtime.h > > > @@ -17,9 +17,20 @@ static inline bool

Re: [PATCH 6/7] cputime: Introduce vtime accounting check for readers

2015-11-23 Thread Frederic Weisbecker
On Mon, Nov 23, 2015 at 03:35:16PM +0100, Peter Zijlstra wrote: > On Mon, Nov 23, 2015 at 03:19:19PM +0100, Frederic Weisbecker wrote: > > On Thu, Nov 19, 2015 at 09:28:28PM +0100, Peter Zijlstra wrote: > > > On Thu, Nov 19, 2015 at 04:47:33PM +0100, Frederic Weisbecker wrote: > > > > +++

Re: [PATCH 6/7] cputime: Introduce vtime accounting check for readers

2015-11-19 Thread Peter Zijlstra
On Thu, Nov 19, 2015 at 04:47:33PM +0100, Frederic Weisbecker wrote: > +++ b/include/linux/vtime.h > @@ -17,9 +17,20 @@ static inline bool vtime_accounting_cpu_enabled(void) { > return true; } > #endif /* CONFIG_VIRT_CPU_ACCOUNTING_NATIVE */ > > #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN > +/* > +

[PATCH 6/7] cputime: Introduce vtime accounting check for readers

2015-11-19 Thread Frederic Weisbecker
Readers need to know if vtime runs at all on some CPU somewhere, this is a fast-path check to determine if we need to check further the need to add up any tickless cputime delta. This fast path check uses context tracking state because vtime is tied to context tracking as of now. This check

Re: [PATCH 6/7] cputime: Introduce vtime accounting check for readers

2015-11-19 Thread Peter Zijlstra
On Thu, Nov 19, 2015 at 04:47:33PM +0100, Frederic Weisbecker wrote: > +++ b/include/linux/vtime.h > @@ -17,9 +17,20 @@ static inline bool vtime_accounting_cpu_enabled(void) { > return true; } > #endif /* CONFIG_VIRT_CPU_ACCOUNTING_NATIVE */ > > #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN > +/* > +

[PATCH 6/7] cputime: Introduce vtime accounting check for readers

2015-11-19 Thread Frederic Weisbecker
Readers need to know if vtime runs at all on some CPU somewhere, this is a fast-path check to determine if we need to check further the need to add up any tickless cputime delta. This fast path check uses context tracking state because vtime is tied to context tracking as of now. This check