Re: [PATCH 5/5] sched/rt: Optimize find_lowest_rq() to select a cache hot cpu

2015-02-04 Thread Xunlei Pang
Hi Peter, Steve, Thanks for all your valuable sharing. I'll keep them in mind. Regards, Xunlei On 30 January 2015 at 03:23, Peter Zijlstra wrote: > On Fri, Jan 30, 2015 at 12:42:47AM +0800, Xunlei Pang wrote: >> On 27 January 2015 at 22:56, Steven Rostedt wrote: >> > On Tue, 27 Jan 2015 15:21:

Re: [PATCH 5/5] sched/rt: Optimize find_lowest_rq() to select a cache hot cpu

2015-01-29 Thread Peter Zijlstra
On Fri, Jan 30, 2015 at 12:42:47AM +0800, Xunlei Pang wrote: > On 27 January 2015 at 22:56, Steven Rostedt wrote: > > On Tue, 27 Jan 2015 15:21:36 +0100 > > Peter Zijlstra wrote: > > > >> On Mon, Jan 19, 2015 at 04:49:40AM +, Xunlei Pang wrote: > >> > In find_lowest_rq(), if we can't find a w

Re: [PATCH 5/5] sched/rt: Optimize find_lowest_rq() to select a cache hot cpu

2015-01-29 Thread Steven Rostedt
On Fri, 30 Jan 2015 00:42:47 +0800 Xunlei Pang wrote: > I think the responsiveness is the most important feature for RT tasks, > so I think: > response latency > cache > SMT in significance. Unfortunately, sometimes cache affects response latency. > > I was wondering if we can take the cpuid

Re: [PATCH 5/5] sched/rt: Optimize find_lowest_rq() to select a cache hot cpu

2015-01-29 Thread Xunlei Pang
On 27 January 2015 at 22:56, Steven Rostedt wrote: > On Tue, 27 Jan 2015 15:21:36 +0100 > Peter Zijlstra wrote: > >> On Mon, Jan 19, 2015 at 04:49:40AM +, Xunlei Pang wrote: >> > In find_lowest_rq(), if we can't find a wake_affine cpu from >> > sched_domain, then we can actually determine a c

Re: [PATCH 5/5] sched/rt: Optimize find_lowest_rq() to select a cache hot cpu

2015-01-27 Thread Peter Zijlstra
On Tue, Jan 27, 2015 at 09:56:26AM -0500, Steven Rostedt wrote: > On Tue, 27 Jan 2015 15:21:36 +0100 > Peter Zijlstra wrote: > > > On Mon, Jan 19, 2015 at 04:49:40AM +, Xunlei Pang wrote: > > > In find_lowest_rq(), if we can't find a wake_affine cpu from > > > sched_domain, then we can actual

Re: [PATCH 5/5] sched/rt: Optimize find_lowest_rq() to select a cache hot cpu

2015-01-27 Thread Steven Rostedt
On Tue, 27 Jan 2015 15:21:36 +0100 Peter Zijlstra wrote: > On Mon, Jan 19, 2015 at 04:49:40AM +, Xunlei Pang wrote: > > In find_lowest_rq(), if we can't find a wake_affine cpu from > > sched_domain, then we can actually determine a cache hot cpu > > instead of simply calling "cpumask_any(lowe

Re: [PATCH 5/5] sched/rt: Optimize find_lowest_rq() to select a cache hot cpu

2015-01-27 Thread Peter Zijlstra
On Mon, Jan 19, 2015 at 04:49:40AM +, Xunlei Pang wrote: > In find_lowest_rq(), if we can't find a wake_affine cpu from > sched_domain, then we can actually determine a cache hot cpu > instead of simply calling "cpumask_any(lowest_mask)" which > always returns the first cpu in the mask. > > So