From: Peter Zijlstra <pet...@infradead.org> Tested-by: Julien Desfossez <jdesfos...@digitalocean.com> Not-Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org> --- kernel/sched/core.c | 37 ++++++++++++++++++++++++++++++++++++- 1 file changed, 36 insertions(+), 1 deletion(-)
diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 211e0784675f..61758b5478d8 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -127,6 +127,10 @@ static inline bool prio_less(struct task_struct *a, struct task_struct *b) int pa = __task_prio(a), pb = __task_prio(b); + trace_printk("(%s/%d;%d,%Lu,%Lu) ?< (%s/%d;%d,%Lu,%Lu)\n", + a->comm, a->pid, pa, a->se.vruntime, a->dl.deadline, + b->comm, b->pid, pb, b->se.vruntime, b->dl.deadline); + if (-pa < -pb) return true; @@ -317,12 +321,16 @@ static void __sched_core_enable(void) static_branch_enable(&__sched_core_enabled); stop_machine(__sched_core_stopper, (void *)true, NULL); + + printk("core sched enabled\n"); } static void __sched_core_disable(void) { stop_machine(__sched_core_stopper, (void *)false, NULL); static_branch_disable(&__sched_core_enabled); + + printk("core sched disabled\n"); } void sched_core_get(void) @@ -4978,6 +4986,13 @@ pick_next_task(struct rq *rq, struct task_struct *prev, struct rq_flags *rf) set_next_task(rq, next); } + trace_printk("pick pre selected (%u %u %u): %s/%d %lx\n", + rq->core->core_task_seq, + rq->core->core_pick_seq, + rq->core_sched_seq, + next->comm, next->pid, + next->core_cookie); + rq->core_pick = NULL; return next; } @@ -5066,6 +5081,8 @@ pick_next_task(struct rq *rq, struct task_struct *prev, struct rq_flags *rf) */ if (i == cpu && !need_sync && !p->core_cookie) { next = p; + trace_printk("unconstrained pick: %s/%d %lx\n", + next->comm, next->pid, next->core_cookie); goto done; } @@ -5074,6 +5091,9 @@ pick_next_task(struct rq *rq, struct task_struct *prev, struct rq_flags *rf) rq_i->core_pick = p; + trace_printk("cpu(%d): selected: %s/%d %lx\n", + i, p->comm, p->pid, p->core_cookie); + /* * If this new candidate is of higher priority than the * previous; and they're incompatible; we need to wipe @@ -5090,6 +5110,8 @@ pick_next_task(struct rq *rq, struct task_struct *prev, struct rq_flags *rf) rq->core->core_cookie = p->core_cookie; max = p; + trace_printk("max: %s/%d %lx\n", max->comm, max->pid, max->core_cookie); + if (old_max) { for_each_cpu(j, smt_mask) { if (j == i) @@ -5120,6 +5142,7 @@ next_class:; /* Something should have been selected for current CPU */ WARN_ON_ONCE(!next); + trace_printk("picked: %s/%d %lx\n", next->comm, next->pid, next->core_cookie); /* * Reschedule siblings @@ -5155,13 +5178,21 @@ next_class:; } /* Did we break L1TF mitigation requirements? */ - WARN_ON_ONCE(!cookie_match(next, rq_i->core_pick)); + if (unlikely(!cookie_match(next, rq_i->core_pick))) { + trace_printk("[%d]: cookie mismatch. %s/%d/0x%lx/0x%lx\n", + rq_i->cpu, rq_i->core_pick->comm, + rq_i->core_pick->pid, + rq_i->core_pick->core_cookie, + rq_i->core->core_cookie); + WARN_ON_ONCE(1); + } if (rq_i->curr == rq_i->core_pick) { rq_i->core_pick = NULL; continue; } + trace_printk("IPI(%d)\n", i); resched_curr(rq_i); } @@ -5209,6 +5240,10 @@ static bool try_steal_cookie(int this, int that) if (p->core_occupation > dst->idle->core_occupation) goto next; + trace_printk("core fill: %s/%d (%d->%d) %d %d %lx\n", + p->comm, p->pid, that, this, + p->core_occupation, dst->idle->core_occupation, cookie); + p->on_rq = TASK_ON_RQ_MIGRATING; deactivate_task(src, p, 0); set_task_cpu(p, this); -- 2.29.0.rc1.297.gfa9743e501-goog