|
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH v2 09/10] xen/tools: tracing: trace (Credit2) runq traversal.
On Thu, Feb 9, 2017 at 1:59 PM, Dario Faggioli
<dario.faggioli@xxxxxxxxxx> wrote:
> When traversing a Credit2 runqueue to select the
> best candidate vCPU to be run next, show in the
> trace which vCPUs we consider.
>
> A bit verbose, but quite useful, considering that
> we may end up looking at, but then discarding, one
> of more vCPU. This will help understand which ones
> are skipped and why.
This sounds useful -- but what I don't quite understand is why it's
useful simply to know that a vcpu was considered, and not also know
specifically why it was decided against. (I'm sure you've found it
useful or you wouldn't have submitted the patch.)
Anyway, I can check it in as-is (if it applies).
Acked-by: George Dunlap <george.dunlap@xxxxxxxxxx>
>
> Also, add how much credits the chosen vCPU has
> (in the TRC_CSCHED2_RUNQ_CANDIDATE record). And,
> while there, fix a bug in tools/xentrace/formats
> (still in the output of TRC_CSCHED2_RUNQ_CANDIDATE).
>
> Signed-off-by: Dario Faggioli <dario.faggioli@xxxxxxxxxx>
> ---
> Cc: George Dunlap <george.dunlap@xxxxxxxxxxxxx>
> ---
> tools/xentrace/formats | 3 ++-
> tools/xentrace/xenalyze.c | 15 +++++++++++++--
> xen/common/sched_credit2.c | 15 +++++++++++++++
> 3 files changed, 30 insertions(+), 3 deletions(-)
>
> diff --git a/tools/xentrace/formats b/tools/xentrace/formats
> index db89f92..72c0b24 100644
> --- a/tools/xentrace/formats
> +++ b/tools/xentrace/formats
> @@ -65,9 +65,10 @@
> 0x00022210 CPU%(cpu)d %(tsc)d (+%(reltsc)8d) csched2:load_check [
> lrq_id[16]:orq_id[16] = 0x%(1)08x, delta = %(2)d ]
> 0x00022211 CPU%(cpu)d %(tsc)d (+%(reltsc)8d) csched2:load_balance [
> l_bavgload = 0x%(2)08x%(1)08x, o_bavgload = 0x%(4)08x%(3)08x,
> lrq_id[16]:orq_id[16] = 0x%(5)08x ]
> 0x00022212 CPU%(cpu)d %(tsc)d (+%(reltsc)8d) csched2:pick_cpu [
> b_avgload = 0x%(2)08x%(1)08x, dom:vcpu = 0x%(3)08x, rq_id[16]:new_cpu[16] =
> %(4)d ]
> -0x00022213 CPU%(cpu)d %(tsc)d (+%(reltsc)8d) csched2:runq_candidate [
> dom:vcpu = 0x%(1)08x, skipped_vcpus = %(2)d tickled_cpu = %(3)d ]
> +0x00022213 CPU%(cpu)d %(tsc)d (+%(reltsc)8d) csched2:runq_candidate [
> dom:vcpu = 0x%(1)08x, credit = %(4)d, skipped_vcpus = %(3)d, tickled_cpu =
> %(2)d ]
> 0x00022214 CPU%(cpu)d %(tsc)d (+%(reltsc)8d) csched2:schedule [
> rq:cpu = 0x%(1)08x, tasklet[8]:idle[8]:smt_idle[8]:tickled[8] = %(2)08x ]
> 0x00022215 CPU%(cpu)d %(tsc)d (+%(reltsc)8d) csched2:ratelimit [
> dom:vcpu = 0x%(1)08x, runtime = %(2)d ]
> +0x00022216 CPU%(cpu)d %(tsc)d (+%(reltsc)8d) csched2:runq_cand_chk [
> dom:vcpu = 0x%(1)08x ]
>
> 0x00022801 CPU%(cpu)d %(tsc)d (+%(reltsc)8d) rtds:tickle [ cpu =
> %(1)d ]
> 0x00022802 CPU%(cpu)d %(tsc)d (+%(reltsc)8d) rtds:runq_pick [
> dom:vcpu = 0x%(1)08x, cur_deadline = 0x%(3)08x%(2)08x, cur_budget =
> 0x%(5)08x%(4)08x ]
> diff --git a/tools/xentrace/xenalyze.c b/tools/xentrace/xenalyze.c
> index a90da20..2678e2a 100644
> --- a/tools/xentrace/xenalyze.c
> +++ b/tools/xentrace/xenalyze.c
> @@ -7825,12 +7825,13 @@ void sched_process(struct pcpu_info *p)
> struct {
> unsigned vcpuid:16, domid:16;
> unsigned tickled_cpu, skipped;
> + int credit;
> } *r = (typeof(r))ri->d;
>
> - printf(" %s csched2:runq_candidate d%uv%u, "
> + printf(" %s csched2:runq_candidate d%uv%u, credit = %d, "
> "%u vcpus skipped, ",
> ri->dump_header, r->domid, r->vcpuid,
> - r->skipped);
> + r->credit, r->skipped);
> if (r->tickled_cpu == (unsigned)-1)
> printf("no cpu was tickled\n");
> else
> @@ -7864,6 +7865,16 @@ void sched_process(struct pcpu_info *p)
> r->runtime / 1000, r->runtime % 1000);
> }
> break;
> + case TRC_SCHED_CLASS_EVT(CSCHED2, 23): /* RUNQ_CAND_CHECK */
> + if(opt.dump_all) {
> + struct {
> + unsigned int vcpuid:16, domid:16;
> + } *r = (typeof(r))ri->d;
> +
> + printf(" %s csched2:runq_cand_check d%uv%u\n",
> + ri->dump_header, r->domid, r->vcpuid);
> + }
> + break;
> /* RTDS (TRC_RTDS_xxx) */
> case TRC_SCHED_CLASS_EVT(RTDS, 1): /* TICKLE */
> if(opt.dump_all) {
> diff --git a/xen/common/sched_credit2.c b/xen/common/sched_credit2.c
> index 8057abf..35d6988 100644
> --- a/xen/common/sched_credit2.c
> +++ b/xen/common/sched_credit2.c
> @@ -57,6 +57,7 @@
> #define TRC_CSCHED2_RUNQ_CANDIDATE TRC_SCHED_CLASS_EVT(CSCHED2, 20)
> #define TRC_CSCHED2_SCHEDULE TRC_SCHED_CLASS_EVT(CSCHED2, 21)
> #define TRC_CSCHED2_RATELIMIT TRC_SCHED_CLASS_EVT(CSCHED2, 22)
> +#define TRC_CSCHED2_RUNQ_CAND_CHECK TRC_SCHED_CLASS_EVT(CSCHED2, 23)
>
> /*
> * WARNING: This is still in an experimental phase. Status and work can be
> found at the
> @@ -2498,6 +2499,18 @@ runq_candidate(struct csched2_runqueue_data *rqd,
> {
> struct csched2_vcpu * svc = list_entry(iter, struct csched2_vcpu,
> runq_elem);
>
> + if ( unlikely(tb_init_done) )
> + {
> + struct {
> + unsigned vcpu:16, dom:16;
> + } d;
> + d.dom = svc->vcpu->domain->domain_id;
> + d.vcpu = svc->vcpu->vcpu_id;
> + __trace_var(TRC_CSCHED2_RUNQ_CAND_CHECK, 1,
> + sizeof(d),
> + (unsigned char *)&d);
> + }
> +
> /* Only consider vcpus that are allowed to run on this processor. */
> if ( !cpumask_test_cpu(cpu, svc->vcpu->cpu_hard_affinity) )
> {
> @@ -2546,9 +2559,11 @@ runq_candidate(struct csched2_runqueue_data *rqd,
> struct {
> unsigned vcpu:16, dom:16;
> unsigned tickled_cpu, skipped;
> + int credit;
> } d;
> d.dom = snext->vcpu->domain->domain_id;
> d.vcpu = snext->vcpu->vcpu_id;
> + d.credit = snext->credit;
> d.tickled_cpu = snext->tickled_cpu;
> d.skipped = *skipped;
> __trace_var(TRC_CSCHED2_RUNQ_CANDIDATE, 1,
>
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@xxxxxxxxxxxxx
> https://lists.xen.org/xen-devel
_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
https://lists.xen.org/xen-devel
|
 |
Lists.xenproject.org is hosted with RackSpace, monitoring our |