Re: [PATCH 6/7] sched: Clean up preempt_enable_no_resched() abuse

2013-11-26 Thread Thomas Gleixner
On Tue, 26 Nov 2013, Eliezer Tamir wrote: > On 22/11/2013 13:30, Peter Zijlstra wrote: > > On Fri, Nov 22, 2013 at 08:56:00AM +0200, Eliezer Tamir wrote: > >> On 21/11/2013 15:39, Peter Zijlstra wrote: > >>> On Thu, Nov 21, 2013 at 03:26:17PM +0200, Eliezer Tamir wrote: > > > > Please use local_c

Re: [PATCH 6/7] sched: Clean up preempt_enable_no_resched() abuse

2013-11-25 Thread Eliezer Tamir
On 22/11/2013 13:30, Peter Zijlstra wrote: > On Fri, Nov 22, 2013 at 08:56:00AM +0200, Eliezer Tamir wrote: >> On 21/11/2013 15:39, Peter Zijlstra wrote: >>> On Thu, Nov 21, 2013 at 03:26:17PM +0200, Eliezer Tamir wrote: > > Please use local_clock(), yes its slightly more expensive, but I doubt >

Re: [PATCH 6/7] sched: Clean up preempt_enable_no_resched() abuse

2013-11-22 Thread Peter Zijlstra
On Fri, Nov 22, 2013 at 08:56:00AM +0200, Eliezer Tamir wrote: > On 21/11/2013 15:39, Peter Zijlstra wrote: > > On Thu, Nov 21, 2013 at 03:26:17PM +0200, Eliezer Tamir wrote: > > >> We don't override any limit the user has put on the system call. > > > > You are in fact, note how the normal selec

Re: [PATCH 6/7] sched: Clean up preempt_enable_no_resched() abuse

2013-11-21 Thread Eliezer Tamir
On 21/11/2013 15:39, Peter Zijlstra wrote: > On Thu, Nov 21, 2013 at 03:26:17PM +0200, Eliezer Tamir wrote: >> We don't override any limit the user has put on the system call. > > You are in fact, note how the normal select @endtime argument is only > set up _after_ you're done polling. So if the

Re: [PATCH 6/7] sched: Clean up preempt_enable_no_resched() abuse

2013-11-20 Thread Eliezer Tamir
On 20/11/2013 18:04, Peter Zijlstra wrote: > The only valid use of preempt_enable_no_resched() is if the very next > line is schedule() or if we know preemption cannot actually be enabled > by that statement due to known more preempt_count 'refs'. The reason I used the no resched version is that b