On Mon, Oct 14, 2019 at 5:57 AM Aaron Lu wrote:
>
> I now remembered why I used max().
>
> Assume rq1 and rq2's min_vruntime are both at 2000 and the core wide
> min_vruntime is also 2000. Also assume both runqueues are empty at the
> moment. Then task t1 is queued to rq1 and runs for a long time
On Sun, Oct 13, 2019 at 08:44:32AM -0400, Vineeth Remanan Pillai wrote:
> On Fri, Oct 11, 2019 at 11:55 PM Aaron Lu wrote:
>
> >
> > I don't think we need do the normalization afterwrads and it appears
> > we are on the same page regarding core wide vruntime.
Should be "we are not on the same pa
On Fri, Oct 11, 2019 at 11:55 PM Aaron Lu wrote:
>
> I don't think we need do the normalization afterwrads and it appears
> we are on the same page regarding core wide vruntime.
>
> The intent of my patch is to treat all the root level sched entities of
> the two siblings as if they are in a sing
On Fri, Oct 11, 2019 at 08:10:30AM -0400, Vineeth Remanan Pillai wrote:
> > Thanks for the clarification.
> >
> > Yes, this is the initialization issue I mentioned before when core
> > scheduling is initially enabled. rq1's vruntime is bumped the first time
> > update_core_cfs_rq_min_vruntime() is
> Thanks for the clarification.
>
> Yes, this is the initialization issue I mentioned before when core
> scheduling is initially enabled. rq1's vruntime is bumped the first time
> update_core_cfs_rq_min_vruntime() is called and if there are already
> some tasks queued, new tasks queued on rq1 will
On Fri, Oct 11, 2019 at 07:32:48AM -0400, Vineeth Remanan Pillai wrote:
> > > The reason we need to do this is because, new tasks that gets created will
> > > have a vruntime based on the new min_vruntime and old tasks will have it
> > > based on the old min_vruntime
> >
> > I think this is expecte
> > The reason we need to do this is because, new tasks that gets created will
> > have a vruntime based on the new min_vruntime and old tasks will have it
> > based on the old min_vruntime
>
> I think this is expected behaviour.
>
I don't think this is the expected behavior. If we hadn't changed t
On Thu, Oct 10, 2019 at 10:29:47AM -0400, Vineeth Remanan Pillai wrote:
> > I didn't see why we need do this.
> >
> > We only need to have the root level sched entities' vruntime become core
> > wide since we will compare vruntime for them across hyperthreads. For
> > sched entities on sub cfs_rqs,
> I didn't see why we need do this.
>
> We only need to have the root level sched entities' vruntime become core
> wide since we will compare vruntime for them across hyperthreads. For
> sched entities on sub cfs_rqs, we never(at least, not now) compare their
> vruntime outside their cfs_rqs.
>
The
On Wed, Oct 02, 2019 at 04:48:14PM -0400, Vineeth Remanan Pillai wrote:
> On Mon, Sep 30, 2019 at 7:53 AM Vineeth Remanan Pillai
> wrote:
> >
> > >
> > Sorry, I misunderstood the fix and I did not initially see the core wide
> > min_vruntime that you tried to maintain in the rq->core. This approac
On Mon, Sep 30, 2019 at 7:53 AM Vineeth Remanan Pillai
wrote:
>
> >
> Sorry, I misunderstood the fix and I did not initially see the core wide
> min_vruntime that you tried to maintain in the rq->core. This approach
> seems reasonable. I think we can fix the potential starvation that you
> mention
> I've made an attempt in the following two patches to address
> the load balancing of mismatched load between the siblings.
>
> It is applied on top of Aaron's patches:
> - sched: Fix incorrect rq tagged as forced idle
> - wrapper for cfs_rq->min_vruntime
> https://lore.kernel.org/lkml/20190725
On Wed, Sep 18, 2019 at 6:16 PM Aubrey Li wrote:
>
> On Thu, Sep 19, 2019 at 4:41 AM Tim Chen wrote:
> >
> > On 9/17/19 6:33 PM, Aubrey Li wrote:
> > > On Sun, Sep 15, 2019 at 10:14 PM Aaron Lu
> > > wrote:
> >
> > >>
> > >> And I have pushed Tim's branch to:
> > >> https://github.com/aaronlu/l
On Thu, Sep 12, 2019 at 8:35 AM Aaron Lu wrote:
> >
> > I think comparing parent's runtime also will have issues once
> > the task group has a lot more threads with different running
> > patterns. One example is a task group with lot of active threads
> > and a thread with fairly less activity. So
On Thu, Sep 26, 2019 at 1:24 AM Tim Chen wrote:
>
> On 9/24/19 7:40 PM, Aubrey Li wrote:
> > On Sat, Sep 7, 2019 at 2:30 AM Tim Chen wrote:
> >> +static inline s64 core_sched_imbalance_delta(int src_cpu, int dst_cpu,
> >> + int src_sibling, int dst_sibling,
> >> +
On 9/24/19 7:40 PM, Aubrey Li wrote:
> On Sat, Sep 7, 2019 at 2:30 AM Tim Chen wrote:
>> +static inline s64 core_sched_imbalance_delta(int src_cpu, int dst_cpu,
>> + int src_sibling, int dst_sibling,
>> + struct task_group *tg, u64 task_load)
>> +{
>> +
On Sat, Sep 7, 2019 at 2:30 AM Tim Chen wrote:
> +static inline s64 core_sched_imbalance_delta(int src_cpu, int dst_cpu,
> + int src_sibling, int dst_sibling,
> + struct task_group *tg, u64 task_load)
> +{
> + struct sched_entity *se, *se_sibling,
On Thu, Sep 19, 2019 at 4:41 AM Tim Chen wrote:
>
> On 9/17/19 6:33 PM, Aubrey Li wrote:
> > On Sun, Sep 15, 2019 at 10:14 PM Aaron Lu
> > wrote:
>
> >>
> >> And I have pushed Tim's branch to:
> >> https://github.com/aaronlu/linux coresched-v3-v5.1.5-test-tim
> >>
> >> Mine:
> >> https://github.
On 9/4/19 6:44 PM, Julien Desfossez wrote:
> +
> +static void coresched_idle_worker_fini(struct rq *rq)
> +{
> + if (rq->core_idle_task) {
> + kthread_stop(rq->core_idle_task);
> + rq->core_idle_task = NULL;
> + }
During testing, I have found access of rq->core_idl
On 9/10/19 7:27 AM, Julien Desfossez wrote:
> On 29-Aug-2019 04:38:21 PM, Peter Zijlstra wrote:
>> On Thu, Aug 29, 2019 at 10:30:51AM -0400, Phil Auld wrote:
>>> I think, though, that you were basically agreeing with me that the current
>>> core scheduler does not close the holes, or am I reading t
On 9/17/19 6:33 PM, Aubrey Li wrote:
> On Sun, Sep 15, 2019 at 10:14 PM Aaron Lu wrote:
>>
>> And I have pushed Tim's branch to:
>> https://github.com/aaronlu/linux coresched-v3-v5.1.5-test-tim
>>
>> Mine:
>> https://github.com/aaronlu/linux coresched-v3-v5.1.5-test-core_vruntime
Aubrey,
Thank
On Sun, Sep 15, 2019 at 10:14 PM Aaron Lu wrote:
>
> On Fri, Sep 13, 2019 at 07:12:52AM +0800, Aubrey Li wrote:
> > On Thu, Sep 12, 2019 at 8:04 PM Aaron Lu wrote:
> > >
> > > On Wed, Sep 11, 2019 at 09:19:02AM -0700, Tim Chen wrote:
> > > > On 9/11/19 7:02 AM, Aaron Lu wrote:
> > > > I think Jul
On Fri, Sep 13, 2019 at 07:12:52AM +0800, Aubrey Li wrote:
> On Thu, Sep 12, 2019 at 8:04 PM Aaron Lu wrote:
> >
> > On Wed, Sep 11, 2019 at 09:19:02AM -0700, Tim Chen wrote:
> > > On 9/11/19 7:02 AM, Aaron Lu wrote:
> > > I think Julien's result show that my patches did not do as well as
> > > yo
On 9/13/19 7:15 AM, Aaron Lu wrote:
> On Thu, Sep 12, 2019 at 10:29:13AM -0700, Tim Chen wrote:
>
>> The better thing to do is to move one task from cgroupA to another core,
>> that has only one cgroupA task so it can be paired up
>> with that lonely cgroupA task. This will eliminate the forced
On Thu, Sep 12, 2019 at 10:29:13AM -0700, Tim Chen wrote:
> On 9/12/19 5:35 AM, Aaron Lu wrote:
> > On Wed, Sep 11, 2019 at 12:47:34PM -0400, Vineeth Remanan Pillai wrote:
>
> >
> > core wide vruntime makes sense when there are multiple tasks of
> > different cgroups queued on the same core. e.g.
On Thu, Sep 12, 2019 at 10:05:43AM -0700, Tim Chen wrote:
> On 9/12/19 5:04 AM, Aaron Lu wrote:
>
> > Well, I have done following tests:
> > 1 Julien's test script: https://paste.debian.net/plainh/834cf45c
> > 2 start two tagged will-it-scale/page_fault1, see how each performs;
> > 3 Aubrey's mysq
On Thu, Sep 12, 2019 at 8:04 PM Aaron Lu wrote:
>
> On Wed, Sep 11, 2019 at 09:19:02AM -0700, Tim Chen wrote:
> > On 9/11/19 7:02 AM, Aaron Lu wrote:
> > I think Julien's result show that my patches did not do as well as
> > your patches for fairness. Aubrey did some other testing with the same
>
On 9/12/19 5:35 AM, Aaron Lu wrote:
> On Wed, Sep 11, 2019 at 12:47:34PM -0400, Vineeth Remanan Pillai wrote:
>
> core wide vruntime makes sense when there are multiple tasks of
> different cgroups queued on the same core. e.g. when there are two
> tasks of cgroupA and one task of cgroupB are que
On 9/12/19 5:04 AM, Aaron Lu wrote:
> Well, I have done following tests:
> 1 Julien's test script: https://paste.debian.net/plainh/834cf45c
> 2 start two tagged will-it-scale/page_fault1, see how each performs;
> 3 Aubrey's mysql test: https://github.com/aubreyli/coresched_bench.git
>
> They all
On Wed, Sep 11, 2019 at 12:47:34PM -0400, Vineeth Remanan Pillai wrote:
> > > So both of you are working on top of my 2 patches that deal with the
> > > fairness issue, but I had the feeling Tim's alternative patches[1] are
> > > simpler than mine and achieves the same result(after the force idle t
On Wed, Sep 11, 2019 at 09:19:02AM -0700, Tim Chen wrote:
> On 9/11/19 7:02 AM, Aaron Lu wrote:
> > Hi Tim & Julien,
> >
> > On Fri, Sep 06, 2019 at 11:30:20AM -0700, Tim Chen wrote:
> >> On 8/7/19 10:10 AM, Tim Chen wrote:
> >>
> >>> 3) Load balancing between CPU cores
> >>> -
> > So both of you are working on top of my 2 patches that deal with the
> > fairness issue, but I had the feeling Tim's alternative patches[1] are
> > simpler than mine and achieves the same result(after the force idle tag
>
> I think Julien's result show that my patches did not do as well as
> yo
On 9/11/19 7:02 AM, Aaron Lu wrote:
> Hi Tim & Julien,
>
> On Fri, Sep 06, 2019 at 11:30:20AM -0700, Tim Chen wrote:
>> On 8/7/19 10:10 AM, Tim Chen wrote:
>>
>>> 3) Load balancing between CPU cores
>>> ---
>>> Say if one CPU core's sibling threads get forced idled
Hi Tim & Julien,
On Fri, Sep 06, 2019 at 11:30:20AM -0700, Tim Chen wrote:
> On 8/7/19 10:10 AM, Tim Chen wrote:
>
> > 3) Load balancing between CPU cores
> > ---
> > Say if one CPU core's sibling threads get forced idled
> > a lot as it has mostly incompatible tas
On 29-Aug-2019 04:38:21 PM, Peter Zijlstra wrote:
> On Thu, Aug 29, 2019 at 10:30:51AM -0400, Phil Auld wrote:
> > I think, though, that you were basically agreeing with me that the current
> > core scheduler does not close the holes, or am I reading that wrong.
>
> Agreed; the missing bits for L1T
On 9/4/19 6:44 PM, Julien Desfossez wrote:
>@@ -3853,7 +3880,7 @@ pick_next_task(struct rq *rq, struct task_struct *prev,
>struct rq_flags *rf)
> goto done;
> }
>
>- if (!is_idle_task(p))
>+ if (!is_fo
On 8/7/19 10:10 AM, Tim Chen wrote:
> 3) Load balancing between CPU cores
> ---
> Say if one CPU core's sibling threads get forced idled
> a lot as it has mostly incompatible tasks between the siblings,
> moving the incompatible load to other cores and pulling
> com
> 1) Unfairness between the sibling threads
> -
> One sibling thread could be suppressing and force idling
> the sibling thread over proportionally. Resulting in
> the force idled CPU not getting run and stall tasks on
> suppressed CPU.
>
> Status:
> i) Aar
On Thu, Aug 29, 2019 at 10:30:51AM -0400, Phil Auld wrote:
> On Wed, Aug 28, 2019 at 06:01:14PM +0200 Peter Zijlstra wrote:
> > On Wed, Aug 28, 2019 at 11:30:34AM -0400, Phil Auld wrote:
> > > On Tue, Aug 27, 2019 at 11:50:35PM +0200 Peter Zijlstra wrote:
> >
> > > > And given MDS, I'm still not e
On Wed, Aug 28, 2019 at 06:01:14PM +0200 Peter Zijlstra wrote:
> On Wed, Aug 28, 2019 at 11:30:34AM -0400, Phil Auld wrote:
> > On Tue, Aug 27, 2019 at 11:50:35PM +0200 Peter Zijlstra wrote:
>
> > > And given MDS, I'm still not entirely convinced it all makes sense. If
> > > it were just L1TF, the
On 8/28/19 9:01 AM, Peter Zijlstra wrote:
> On Wed, Aug 28, 2019 at 11:30:34AM -0400, Phil Auld wrote:
>> On Tue, Aug 27, 2019 at 11:50:35PM +0200 Peter Zijlstra wrote:
>
>> The current core scheduler implementation, I believe, still has
>> (theoretical?)
>> holes involving interrupts, once/if t
On Wed, Aug 28, 2019 at 08:59:21AM -0700, Tim Chen wrote:
> On 8/27/19 2:50 PM, Peter Zijlstra wrote:
> > On Tue, Aug 27, 2019 at 10:14:17PM +0100, Matthew Garrett wrote:
> >> Apple have provided a sysctl that allows applications to indicate that
> >> specific threads should make use of core isola
On Wed, Aug 28, 2019 at 11:30:34AM -0400, Phil Auld wrote:
> On Tue, Aug 27, 2019 at 11:50:35PM +0200 Peter Zijlstra wrote:
> > And given MDS, I'm still not entirely convinced it all makes sense. If
> > it were just L1TF, then yes, but now...
>
> I was thinking MDS is really the reason for this.
On 8/27/19 2:50 PM, Peter Zijlstra wrote:
> On Tue, Aug 27, 2019 at 10:14:17PM +0100, Matthew Garrett wrote:
>> Apple have provided a sysctl that allows applications to indicate that
>> specific threads should make use of core isolation while allowing
>> the rest of the system to make use of SMT,
On Tue, Aug 27, 2019 at 11:50:35PM +0200 Peter Zijlstra wrote:
> On Tue, Aug 27, 2019 at 10:14:17PM +0100, Matthew Garrett wrote:
> > Apple have provided a sysctl that allows applications to indicate that
> > specific threads should make use of core isolation while allowing
> > the rest of the sy
On Wed, Aug 28, 2019 at 5:14 AM Matthew Garrett wrote:
>
> Apple have provided a sysctl that allows applications to indicate that
> specific threads should make use of core isolation while allowing
> the rest of the system to make use of SMT, and browsers (Safari, Firefox
> and Chrome, at least) a
On Tue, Aug 27, 2019 at 10:14:17PM +0100, Matthew Garrett wrote:
> Apple have provided a sysctl that allows applications to indicate that
> specific threads should make use of core isolation while allowing
> the rest of the system to make use of SMT, and browsers (Safari, Firefox
> and Chrome, a
Apple have provided a sysctl that allows applications to indicate that
specific threads should make use of core isolation while allowing
the rest of the system to make use of SMT, and browsers (Safari, Firefox
and Chrome, at least) are now making use of this. Trying to do something
similar usin
On Thu, Aug 15, 2019 at 06:09:28PM +0200, Dario Faggioli wrote:
> On Wed, 2019-08-07 at 10:10 -0700, Tim Chen wrote:
> > On 8/7/19 1:58 AM, Dario Faggioli wrote:
> >
> > > Since I see that, in this thread, there are various patches being
> > > proposed and discussed... should I rerun my benchmarks
On Wed, 2019-08-07 at 10:10 -0700, Tim Chen wrote:
> On 8/7/19 1:58 AM, Dario Faggioli wrote:
>
> > Since I see that, in this thread, there are various patches being
> > proposed and discussed... should I rerun my benchmarks with them
> > applied? If yes, which ones? And is there, by any chance, o
On 2019/8/12 23:38, Vineeth Remanan Pillai wrote:
>> I have two other small changes that I think are worth sending out.
>>
>> The first simplify logic in pick_task() and the 2nd avoid task pick all
>> over again when max is preempted. I also refined the previous hack patch to
>> make schedule alway
> I have two other small changes that I think are worth sending out.
>
> The first simplify logic in pick_task() and the 2nd avoid task pick all
> over again when max is preempted. I also refined the previous hack patch to
> make schedule always happen only for root cfs rq. Please see below for
> d
On Thu, Aug 08, 2019 at 09:39:45AM -0700, Tim Chen wrote:
> On 8/8/19 5:55 AM, Aaron Lu wrote:
> > On Mon, Aug 05, 2019 at 08:55:28AM -0700, Tim Chen wrote:
> >> On 8/2/19 8:37 AM, Julien Desfossez wrote:
> >>> We tested both Aaron's and Tim's patches and here are our results.
>
> >
> > diff --gi
On Thu, Aug 08, 2019 at 02:42:57PM -0700, Tim Chen wrote:
> On 8/8/19 10:27 AM, Tim Chen wrote:
> > On 8/7/19 11:47 PM, Aaron Lu wrote:
> >> On Tue, Aug 06, 2019 at 02:19:57PM -0700, Tim Chen wrote:
> >>> +void account_core_idletime(struct task_struct *p, u64 exec)
> >>> +{
> >>> + const struct cpu
On 8/8/19 10:27 AM, Tim Chen wrote:
> On 8/7/19 11:47 PM, Aaron Lu wrote:
>> On Tue, Aug 06, 2019 at 02:19:57PM -0700, Tim Chen wrote:
>>> +void account_core_idletime(struct task_struct *p, u64 exec)
>>> +{
>>> + const struct cpumask *smt_mask;
>>> + struct rq *rq;
>>> + bool force_idle, refi
On 8/7/19 11:47 PM, Aaron Lu wrote:
> On Tue, Aug 06, 2019 at 02:19:57PM -0700, Tim Chen wrote:
>> +void account_core_idletime(struct task_struct *p, u64 exec)
>> +{
>> +const struct cpumask *smt_mask;
>> +struct rq *rq;
>> +bool force_idle, refill;
>> +int i, cpu;
>> +
>> +rq =
On 8/8/19 5:55 AM, Aaron Lu wrote:
> On Mon, Aug 05, 2019 at 08:55:28AM -0700, Tim Chen wrote:
>> On 8/2/19 8:37 AM, Julien Desfossez wrote:
>>> We tested both Aaron's and Tim's patches and here are our results.
>
> diff --git a/kernel/sched/core.c b/kernel/sched/core.c
> index 26fea68f7f54..5429
On Mon, Aug 05, 2019 at 08:55:28AM -0700, Tim Chen wrote:
> On 8/2/19 8:37 AM, Julien Desfossez wrote:
> > We tested both Aaron's and Tim's patches and here are our results.
> >
> > Test setup:
> > - 2 1-thread sysbench, one running the cpu benchmark, the other one the
> > mem benchmark
> > - bo
On Tue, Aug 06, 2019 at 02:19:57PM -0700, Tim Chen wrote:
> +void account_core_idletime(struct task_struct *p, u64 exec)
> +{
> + const struct cpumask *smt_mask;
> + struct rq *rq;
> + bool force_idle, refill;
> + int i, cpu;
> +
> + rq = task_rq(p);
> + if (!sched_core_enab
On 8/7/19 1:58 AM, Dario Faggioli wrote:
> So, here comes my question: I've done a benchmarking campaign (yes,
> I'll post numbers soon) using this branch:
>
> https://github.com/digitalocean/linux-coresched.git
> vpillai/coresched-v3-v5.1.5-test
> https://github.com/digitalocean/linux-coresche
Hello everyone,
This is Dario, from SUSE. I'm also interesting in core-scheduling, and
using it in virtualization use cases.
Just for context, I'm working in virt since a few years, mostly on Xen,
but I've done Linux stuff before, and I am getting back at it.
For now, I've been looking at the co
On 8/6/19 10:12 AM, Peter Zijlstra wrote:
>> I'm wondering if something simpler will work. It is easier to maintain
>> fairness
>> between the CPU threads. A simple scheme may be if the force idle deficit
>> on a CPU thread exceeds a threshold compared to its sibling, we will
>> bias in choosin
On Tue, Aug 06, 2019 at 10:03:29AM -0700, Tim Chen wrote:
> On 8/5/19 8:24 PM, Aaron Lu wrote:
>
> > I've been thinking if we should consider core wide tenent fairness?
> >
> > Let's say there are 3 tasks on 2 threads' rq of the same core, 2 tasks
> > (e.g. A1, A2) belong to tenent A and the 3rd
On 8/5/19 8:24 PM, Aaron Lu wrote:
> I've been thinking if we should consider core wide tenent fairness?
>
> Let's say there are 3 tasks on 2 threads' rq of the same core, 2 tasks
> (e.g. A1, A2) belong to tenent A and the 3rd B1 belong to another tenent
> B. Assume A1 and B1 are queued on the sa
> I think tenant will have per core weight, similar to sched entity's per
> cpu weight. The tenant's per core weight could derive from its
> corresponding taskgroup's per cpu sched entities' weight(sum them up
> perhaps). Tenant with higher weight will have its core wide vruntime
> advance slower t
>
> What accounting in particular is upset? Is it things like
> select_idle_sibling() that thinks the thread is idle and tries to place
> tasks there?
>
The major issue that we saw was, certain work load causes the idle cpu to never
wakeup and schedule again even when there are runnable threads in
On Tue, Aug 06, 2019 at 10:41:25PM +0800 Aaron Lu wrote:
> On 2019/8/6 22:17, Phil Auld wrote:
> > On Tue, Aug 06, 2019 at 09:54:01PM +0800 Aaron Lu wrote:
> >> On Mon, Aug 05, 2019 at 04:09:15PM -0400, Phil Auld wrote:
> >>> Hi,
> >>>
> >>> On Fri, Aug 02, 2019 at 11:37:15AM -0400 Julien Desfossez
On 2019/8/6 22:17, Phil Auld wrote:
> On Tue, Aug 06, 2019 at 09:54:01PM +0800 Aaron Lu wrote:
>> On Mon, Aug 05, 2019 at 04:09:15PM -0400, Phil Auld wrote:
>>> Hi,
>>>
>>> On Fri, Aug 02, 2019 at 11:37:15AM -0400 Julien Desfossez wrote:
We tested both Aaron's and Tim's patches and here are ou
On Tue, Aug 06, 2019 at 09:54:01PM +0800 Aaron Lu wrote:
> On Mon, Aug 05, 2019 at 04:09:15PM -0400, Phil Auld wrote:
> > Hi,
> >
> > On Fri, Aug 02, 2019 at 11:37:15AM -0400 Julien Desfossez wrote:
> > > We tested both Aaron's and Tim's patches and here are our results.
> > >
> > > Test setup:
>
On Tue, Aug 06, 2019 at 08:24:17AM -0400, Vineeth Remanan Pillai wrote:
> Peter's rebalance logic actually takes care of most of the runq
> imbalance caused
> due to cookie tagging. What we have found from our testing is, fairness issue
> is
> caused mostly due to a Hyperthread going idle and not
On Mon, Aug 05, 2019 at 04:09:15PM -0400, Phil Auld wrote:
> Hi,
>
> On Fri, Aug 02, 2019 at 11:37:15AM -0400 Julien Desfossez wrote:
> > We tested both Aaron's and Tim's patches and here are our results.
> >
> > Test setup:
> > - 2 1-thread sysbench, one running the cpu benchmark, the other one
On Tue, Aug 06, 2019 at 08:24:17AM -0400, Vineeth Remanan Pillai wrote:
> > >
> > > I also think a way to make fairness per cookie per core, is this what you
> > > want to propose?
> >
> > Yes, that's what I meant.
>
> I think that would hurt some kind of workloads badly, especially if
> one tenan
> >
> > I also think a way to make fairness per cookie per core, is this what you
> > want to propose?
>
> Yes, that's what I meant.
I think that would hurt some kind of workloads badly, especially if
one tenant is
having way more tasks than the other. Tenant with more task on the same core
might
On 2019/8/6 14:56, Aubrey Li wrote:
> On Tue, Aug 6, 2019 at 11:24 AM Aaron Lu wrote:
>> I've been thinking if we should consider core wide tenent fairness?
>>
>> Let's say there are 3 tasks on 2 threads' rq of the same core, 2 tasks
>> (e.g. A1, A2) belong to tenent A and the 3rd B1 belong to ano
On Tue, Aug 6, 2019 at 11:24 AM Aaron Lu wrote:
>
> On Mon, Aug 05, 2019 at 08:55:28AM -0700, Tim Chen wrote:
> > On 8/2/19 8:37 AM, Julien Desfossez wrote:
> > > We tested both Aaron's and Tim's patches and here are our results.
> > >
> > > Test setup:
> > > - 2 1-thread sysbench, one running the
On Mon, Aug 05, 2019 at 08:55:28AM -0700, Tim Chen wrote:
> On 8/2/19 8:37 AM, Julien Desfossez wrote:
> > We tested both Aaron's and Tim's patches and here are our results.
> >
> > Test setup:
> > - 2 1-thread sysbench, one running the cpu benchmark, the other one the
> > mem benchmark
> > - bo
Hi,
On Fri, Aug 02, 2019 at 11:37:15AM -0400 Julien Desfossez wrote:
> We tested both Aaron's and Tim's patches and here are our results.
>
> Test setup:
> - 2 1-thread sysbench, one running the cpu benchmark, the other one the
> mem benchmark
> - both started at the same time
> - both are pinn
On 8/2/19 8:37 AM, Julien Desfossez wrote:
> We tested both Aaron's and Tim's patches and here are our results.
>
> Test setup:
> - 2 1-thread sysbench, one running the cpu benchmark, the other one the
> mem benchmark
> - both started at the same time
> - both are pinned on the same core (2 hard
We tested both Aaron's and Tim's patches and here are our results.
Test setup:
- 2 1-thread sysbench, one running the cpu benchmark, the other one the
mem benchmark
- both started at the same time
- both are pinned on the same core (2 hardware threads)
- 10 30-seconds runs
- test script: https:/
On 2019/7/26 23:21, Julien Desfossez wrote:
> On 25-Jul-2019 10:30:03 PM, Aaron Lu wrote:
>>
>> I tried a different approach based on vruntime with 3 patches following.
> [...]
>
> We have experimented with this new patchset and indeed the fairness is
> now much better. Interactive tasks with v3 w
On 7/26/19 8:21 AM, Julien Desfossez wrote:
> On 25-Jul-2019 10:30:03 PM, Aaron Lu wrote:
>>
>> I tried a different approach based on vruntime with 3 patches following.
> [...]
>
> We have experimented with this new patchset and indeed the fairness is
> now much better. Interactive tasks with v3 w
On 25-Jul-2019 10:30:03 PM, Aaron Lu wrote:
>
> I tried a different approach based on vruntime with 3 patches following.
[...]
We have experimented with this new patchset and indeed the fairness is
now much better. Interactive tasks with v3 were complete starving when
there were cpu-intensive tas
On 2019/7/25 22:30, Aaron Lu wrote:
> On Mon, Jul 22, 2019 at 06:26:46PM +0800, Aubrey Li wrote:
>> The granularity period of util_avg seems too large to decide task priority
>> during pick_task(), at least it is in my case, cfs_prio_less() always picked
>> core max task, so pick_task() eventually
On Mon, Jul 22, 2019 at 06:26:46PM +0800, Aubrey Li wrote:
> The granularity period of util_avg seems too large to decide task priority
> during pick_task(), at least it is in my case, cfs_prio_less() always picked
> core max task, so pick_task() eventually picked idle, which causes this change
> n
On Mon, Jul 22, 2019 at 6:43 PM Aaron Lu wrote:
>
> On 2019/7/22 18:26, Aubrey Li wrote:
> > The granularity period of util_avg seems too large to decide task priority
> > during pick_task(), at least it is in my case, cfs_prio_less() always picked
> > core max task, so pick_task() eventually pick
On 2019/7/22 18:26, Aubrey Li wrote:
> The granularity period of util_avg seems too large to decide task priority
> during pick_task(), at least it is in my case, cfs_prio_less() always picked
> core max task, so pick_task() eventually picked idle, which causes this change
> not very helpful for my
On Thu, Jul 18, 2019 at 6:07 PM Aaron Lu wrote:
>
> On Wed, Jun 19, 2019 at 02:33:02PM -0400, Julien Desfossez wrote:
> > On 17-Jun-2019 10:51:27 AM, Aubrey Li wrote:
> > > The result looks still unfair, and particularly, the variance is too high,
> >
> > I just want to confirm that I am also seei
On 7/18/19 10:52 PM, Aaron Lu wrote:
> On Thu, Jul 18, 2019 at 04:27:19PM -0700, Tim Chen wrote:
>>
>>
>> On 7/18/19 3:07 AM, Aaron Lu wrote:
>>> On Wed, Jun 19, 2019 at 02:33:02PM -0400, Julien Desfossez wrote:
>>
>>>
>>> With the below patch on top of v3 that makes use of util_avg to decide
>>> w
On Fri, Jul 19, 2019 at 1:53 PM Aaron Lu wrote:
>
> On Thu, Jul 18, 2019 at 04:27:19PM -0700, Tim Chen wrote:
> >
> >
> > On 7/18/19 3:07 AM, Aaron Lu wrote:
> > > On Wed, Jun 19, 2019 at 02:33:02PM -0400, Julien Desfossez wrote:
> >
> > >
> > > With the below patch on top of v3 that makes use of
On Thu, Jul 18, 2019 at 04:27:19PM -0700, Tim Chen wrote:
>
>
> On 7/18/19 3:07 AM, Aaron Lu wrote:
> > On Wed, Jun 19, 2019 at 02:33:02PM -0400, Julien Desfossez wrote:
>
> >
> > With the below patch on top of v3 that makes use of util_avg to decide
> > which task win, I can do all 8 steps and
On 7/18/19 3:07 AM, Aaron Lu wrote:
> On Wed, Jun 19, 2019 at 02:33:02PM -0400, Julien Desfossez wrote:
>
> With the below patch on top of v3 that makes use of util_avg to decide
> which task win, I can do all 8 steps and the final scores of the 2
> workloads are: 1796191 and 2199586. The scor
On Wed, Jun 19, 2019 at 02:33:02PM -0400, Julien Desfossez wrote:
> On 17-Jun-2019 10:51:27 AM, Aubrey Li wrote:
> > The result looks still unfair, and particularly, the variance is too high,
>
> I just want to confirm that I am also seeing the same issue with a
> similar setup. I also tried with
On 17-Jun-2019 10:51:27 AM, Aubrey Li wrote:
> The result looks still unfair, and particularly, the variance is too high,
I just want to confirm that I am also seeing the same issue with a
similar setup. I also tried with the priority boost fix we previously
posted, the results are slightly better
On Thu, Jun 13, 2019 at 11:22 AM Julien Desfossez
wrote:
>
> On 12-Jun-2019 05:03:08 PM, Subhra Mazumdar wrote:
> >
> > On 6/12/19 9:33 AM, Julien Desfossez wrote:
> > >After reading more traces and trying to understand why only untagged
> > >tasks are starving when there are cpu-intensive tasks r
On 6/12/19 9:33 AM, Julien Desfossez wrote:
After reading more traces and trying to understand why only untagged
tasks are starving when there are cpu-intensive tasks running on the
same set of CPUs, we noticed a difference in behavior in ‘pick_task’. In
the case where ‘core_cookie’ is 0, we ar
On 12-Jun-2019 05:03:08 PM, Subhra Mazumdar wrote:
>
> On 6/12/19 9:33 AM, Julien Desfossez wrote:
> >After reading more traces and trying to understand why only untagged
> >tasks are starving when there are cpu-intensive tasks running on the
> >same set of CPUs, we noticed a difference in behavio
After reading more traces and trying to understand why only untagged
tasks are starving when there are cpu-intensive tasks running on the
same set of CPUs, we noticed a difference in behavior in ‘pick_task’. In
the case where ‘core_cookie’ is 0, we are supposed to only prefer the
tagged task if it’
> The data on my side looks good with CORESCHED_STALL_FIX = true.
Thank you for testing this fix, I'm glad it works for this use-case as
well.
We will be posting another (simpler) version today, stay tuned :-)
Julien
On 2019/6/6 23:26, Julien Desfossez wrote:
> As mentioned above, we have come up with a fix for the long starvation
> of untagged interactive threads competing for the same core with tagged
> threads at the same priority. The idea is to detect the stall and boost
> the stalling threads priority so
On 31-May-2019 05:08:16 PM, Julien Desfossez wrote:
> > My first reaction is: when shell wakes up from sleep, it will
> > fork date. If the script is untagged and those workloads are
> > tagged and all available cores are already running workload
> > threads, the forked date can lose to the running
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