Re: [RFD] sched/deadline: Support single CPU affinity

On Thu, Dec 15, 2016 at 12:30:43PM +0100, Tommaso Cucinotta wrote: > Hi Peter, > > On 13/12/2016 11:21, Peter Zijlstra wrote: > >On Thu, Nov 10, 2016 at 11:01:59AM +0100, Tommaso Cucinotta wrote: > >>Just a note: if you want to recover arbitrary task affinities, you can > >>re-cast your above

Re: [RFD] sched/deadline: Support single CPU affinity

On Thu, Dec 15, 2016 at 12:30:43PM +0100, Tommaso Cucinotta wrote: > Hi Peter, > > On 13/12/2016 11:21, Peter Zijlstra wrote: > >On Thu, Nov 10, 2016 at 11:01:59AM +0100, Tommaso Cucinotta wrote: > >>Just a note: if you want to recover arbitrary task affinities, you can > >>re-cast your above

Re: [RFD] sched/deadline: Support single CPU affinity

Hi Peter, On 13/12/2016 11:21, Peter Zijlstra wrote: On Thu, Nov 10, 2016 at 11:01:59AM +0100, Tommaso Cucinotta wrote: Just a note: if you want to recover arbitrary task affinities, you can re-cast your above test like this: for_each_processor(cpu) \sum U[t]/A[t] \leq 1 (or U_max), for

Re: [RFD] sched/deadline: Support single CPU affinity

Hi Peter, On 13/12/2016 11:21, Peter Zijlstra wrote: On Thu, Nov 10, 2016 at 11:01:59AM +0100, Tommaso Cucinotta wrote: Just a note: if you want to recover arbitrary task affinities, you can re-cast your above test like this: for_each_processor(cpu) \sum U[t]/A[t] \leq 1 (or U_max), for

Re: [RFD] sched/deadline: Support single CPU affinity

On Thu, Nov 10, 2016 at 11:01:59AM +0100, Tommaso Cucinotta wrote: > > Just a note: if you want to recover arbitrary task affinities, you can > re-cast your above test like this: > > for_each_processor(cpu) > \sum U[t]/A[t] \leq 1 (or U_max), for each task t on cpu, with utilization > U[t]

Re: [RFD] sched/deadline: Support single CPU affinity

On Thu, Nov 10, 2016 at 11:01:59AM +0100, Tommaso Cucinotta wrote: > > Just a note: if you want to recover arbitrary task affinities, you can > re-cast your above test like this: > > for_each_processor(cpu) > \sum U[t]/A[t] \leq 1 (or U_max), for each task t on cpu, with utilization > U[t]

Re: [RFD] sched/deadline: Support single CPU affinity

Hi Henrik, On Thu, 10 Nov 2016 13:56:35 +0100 Henrik Austad wrote: > On Thu, Nov 10, 2016 at 01:38:40PM +0100, luca abeni wrote: > > Hi Henrik, > > Hi Luca, > > > On Thu, 10 Nov 2016 13:21:00 +0100 > > Henrik Austad wrote: > > > On Thu, Nov 10, 2016 at

Re: [RFD] sched/deadline: Support single CPU affinity

Hi Henrik, On Thu, 10 Nov 2016 13:56:35 +0100 Henrik Austad wrote: > On Thu, Nov 10, 2016 at 01:38:40PM +0100, luca abeni wrote: > > Hi Henrik, > > Hi Luca, > > > On Thu, 10 Nov 2016 13:21:00 +0100 > > Henrik Austad wrote: > > > On Thu, Nov 10, 2016 at 09:08:07AM +0100, Peter Zijlstra

Re: [RFD] sched/deadline: Support single CPU affinity

On Thu, 10 Nov 2016 12:03:47 +0100 Tommaso Cucinotta wrote: > On 10/11/2016 10:06, luca abeni wrote: > > is equivalent to the "least laxity first" (LLF) algorithm. > > Giving precedence to tasks with 0 laxity is a technique that is > > often used to improve the

Re: [RFD] sched/deadline: Support single CPU affinity

On Thu, 10 Nov 2016 12:03:47 +0100 Tommaso Cucinotta wrote: > On 10/11/2016 10:06, luca abeni wrote: > > is equivalent to the "least laxity first" (LLF) algorithm. > > Giving precedence to tasks with 0 laxity is a technique that is > > often used to improve the schedulability on multi-processor

Re: [RFD] sched/deadline: Support single CPU affinity

On Thu, Nov 10, 2016 at 01:38:40PM +0100, luca abeni wrote: > Hi Henrik, Hi Luca, > On Thu, 10 Nov 2016 13:21:00 +0100 > Henrik Austad wrote: > > On Thu, Nov 10, 2016 at 09:08:07AM +0100, Peter Zijlstra wrote: > [...] > > > We define the time to fail as: > > > > > > ttf(t)

Re: [RFD] sched/deadline: Support single CPU affinity

On Thu, Nov 10, 2016 at 01:38:40PM +0100, luca abeni wrote: > Hi Henrik, Hi Luca, > On Thu, 10 Nov 2016 13:21:00 +0100 > Henrik Austad wrote: > > On Thu, Nov 10, 2016 at 09:08:07AM +0100, Peter Zijlstra wrote: > [...] > > > We define the time to fail as: > > > > > > ttf(t) := t_d - t_b;

Re: [RFD] sched/deadline: Support single CPU affinity

On Thu, Nov 10, 2016 at 01:21:00PM +0100, Henrik Austad wrote: > On Thu, Nov 10, 2016 at 09:08:07AM +0100, Peter Zijlstra wrote: > > We define the time to fail as: > > > > ttf(t) := t_d - t_b; where > > > > t_d is t's absolute deadline > > t_b is t's remaining budget > > > > This is

Re: [RFD] sched/deadline: Support single CPU affinity

On Thu, Nov 10, 2016 at 01:21:00PM +0100, Henrik Austad wrote: > On Thu, Nov 10, 2016 at 09:08:07AM +0100, Peter Zijlstra wrote: > > We define the time to fail as: > > > > ttf(t) := t_d - t_b; where > > > > t_d is t's absolute deadline > > t_b is t's remaining budget > > > > This is

Re: [RFD] sched/deadline: Support single CPU affinity

Hi Henrik, On Thu, 10 Nov 2016 13:21:00 +0100 Henrik Austad wrote: > On Thu, Nov 10, 2016 at 09:08:07AM +0100, Peter Zijlstra wrote: [...] > > We define the time to fail as: > > > > ttf(t) := t_d - t_b; where > > > > t_d is t's absolute deadline > > t_b is t's

Re: [RFD] sched/deadline: Support single CPU affinity

Hi Henrik, On Thu, 10 Nov 2016 13:21:00 +0100 Henrik Austad wrote: > On Thu, Nov 10, 2016 at 09:08:07AM +0100, Peter Zijlstra wrote: [...] > > We define the time to fail as: > > > > ttf(t) := t_d - t_b; where > > > > t_d is t's absolute deadline > > t_b is t's remaining budget > > >

Re: [RFD] sched/deadline: Support single CPU affinity

Hi Peter, On Thu, 10 Nov 2016 11:59:18 +0100 Peter Zijlstra wrote: [...] > > > MIXED CRITICALITY SCHEDULING > > > > > > Since we want to provide better guarantees for single CPU affine > > > tasks than the G-EDF scheduler provides for the single CPU tasks, > > > we need

Re: [RFD] sched/deadline: Support single CPU affinity

Hi Peter, On Thu, 10 Nov 2016 11:59:18 +0100 Peter Zijlstra wrote: [...] > > > MIXED CRITICALITY SCHEDULING > > > > > > Since we want to provide better guarantees for single CPU affine > > > tasks than the G-EDF scheduler provides for the single CPU tasks, > > > we need to somehow alter the

Re: [RFD] sched/deadline: Support single CPU affinity

On Thu, Nov 10, 2016 at 09:08:07AM +0100, Peter Zijlstra wrote: > > > Add support for single CPU affinity to SCHED_DEADLINE; the supposed reason for > wanting single CPU affinity is better QoS than provided by G-EDF. > > Therefore the aim is to provide harder guarantees, similar to UP, for

Re: [RFD] sched/deadline: Support single CPU affinity

On Thu, Nov 10, 2016 at 09:08:07AM +0100, Peter Zijlstra wrote: > > > Add support for single CPU affinity to SCHED_DEADLINE; the supposed reason for > wanting single CPU affinity is better QoS than provided by G-EDF. > > Therefore the aim is to provide harder guarantees, similar to UP, for

Re: [RFD] sched/deadline: Support single CPU affinity

On 10/11/2016 10:06, luca abeni wrote: is equivalent to the "least laxity first" (LLF) algorithm. Giving precedence to tasks with 0 laxity is a technique that is often used to improve the schedulability on multi-processor systems. EDZL (EDF / Zero Laxity first), right? AFAICR, there's quite a

Re: [RFD] sched/deadline: Support single CPU affinity

On 10/11/2016 10:06, luca abeni wrote: is equivalent to the "least laxity first" (LLF) algorithm. Giving precedence to tasks with 0 laxity is a technique that is often used to improve the schedulability on multi-processor systems. EDZL (EDF / Zero Laxity first), right? AFAICR, there's quite a

Re: [RFD] sched/deadline: Support single CPU affinity

On Thu, Nov 10, 2016 at 10:06:02AM +0100, luca abeni wrote: > Hi Peter, > > On Thu, 10 Nov 2016 09:08:07 +0100 > Peter Zijlstra wrote: > > > Add support for single CPU affinity to SCHED_DEADLINE; the supposed > > reason for wanting single CPU affinity is better QoS than

Re: [RFD] sched/deadline: Support single CPU affinity

On Thu, Nov 10, 2016 at 10:06:02AM +0100, luca abeni wrote: > Hi Peter, > > On Thu, 10 Nov 2016 09:08:07 +0100 > Peter Zijlstra wrote: > > > Add support for single CPU affinity to SCHED_DEADLINE; the supposed > > reason for wanting single CPU affinity is better QoS than provided by > > G-EDF. >

Re: [RFD] sched/deadline: Support single CPU affinity

Hi, On 10/11/2016 09:08, Peter Zijlstra wrote: Add support for single CPU affinity to SCHED_DEADLINE; the supposed reason for wanting single CPU affinity is better QoS than provided by G-EDF. Therefore the aim is to provide harder guarantees, similar to UP, for single CPU affine tasks. This

Re: [RFD] sched/deadline: Support single CPU affinity

Hi, On 10/11/2016 09:08, Peter Zijlstra wrote: Add support for single CPU affinity to SCHED_DEADLINE; the supposed reason for wanting single CPU affinity is better QoS than provided by G-EDF. Therefore the aim is to provide harder guarantees, similar to UP, for single CPU affine tasks. This

Re: [RFD] sched/deadline: Support single CPU affinity

Hi Peter, On Thu, 10 Nov 2016 09:08:07 +0100 Peter Zijlstra wrote: > Add support for single CPU affinity to SCHED_DEADLINE; the supposed > reason for wanting single CPU affinity is better QoS than provided by > G-EDF. This looks very interesting, thanks for sharing! I have

Re: [RFD] sched/deadline: Support single CPU affinity

Hi Peter, On Thu, 10 Nov 2016 09:08:07 +0100 Peter Zijlstra wrote: > Add support for single CPU affinity to SCHED_DEADLINE; the supposed > reason for wanting single CPU affinity is better QoS than provided by > G-EDF. This looks very interesting, thanks for sharing! I have some "theoretical"

[RFD] sched/deadline: Support single CPU affinity

Add support for single CPU affinity to SCHED_DEADLINE; the supposed reason for wanting single CPU affinity is better QoS than provided by G-EDF. Therefore the aim is to provide harder guarantees, similar to UP, for single CPU affine tasks. This then leads to a mixed criticality scheduling

[RFD] sched/deadline: Support single CPU affinity

Add support for single CPU affinity to SCHED_DEADLINE; the supposed reason for wanting single CPU affinity is better QoS than provided by G-EDF. Therefore the aim is to provide harder guarantees, similar to UP, for single CPU affine tasks. This then leads to a mixed criticality scheduling