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Message-Id: <20201020014336.2076526-27-joel@joelfernandes.org>
Date: Mon, 19 Oct 2020 21:43:36 -0400
From: "Joel Fernandes (Google)" <joel@...lfernandes.org>
To: Nishanth Aravamudan <naravamudan@...italocean.com>,
Julien Desfossez <jdesfossez@...italocean.com>,
Peter Zijlstra <peterz@...radead.org>,
Tim Chen <tim.c.chen@...ux.intel.com>,
Vineeth Pillai <viremana@...ux.microsoft.com>,
Aaron Lu <aaron.lwe@...il.com>,
Aubrey Li <aubrey.intel@...il.com>, tglx@...utronix.de,
linux-kernel@...r.kernel.org
Cc: mingo@...nel.org, torvalds@...ux-foundation.org,
fweisbec@...il.com, keescook@...omium.org, kerrnel@...gle.com,
Phil Auld <pauld@...hat.com>,
Valentin Schneider <valentin.schneider@....com>,
Mel Gorman <mgorman@...hsingularity.net>,
Pawan Gupta <pawan.kumar.gupta@...ux.intel.com>,
Paolo Bonzini <pbonzini@...hat.com>, joel@...lfernandes.org,
vineeth@...byteword.org, Chen Yu <yu.c.chen@...el.com>,
Christian Brauner <christian.brauner@...ntu.com>,
Agata Gruza <agata.gruza@...el.com>,
Antonio Gomez Iglesias <antonio.gomez.iglesias@...el.com>,
graf@...zon.com, konrad.wilk@...cle.com, dfaggioli@...e.com,
pjt@...gle.com, rostedt@...dmis.org, derkling@...gle.com,
benbjiang@...cent.com,
Alexandre Chartre <alexandre.chartre@...cle.com>,
James.Bottomley@...senpartnership.com, OWeisse@...ch.edu,
Dhaval Giani <dhaval.giani@...cle.com>,
Junaid Shahid <junaids@...gle.com>, jsbarnes@...gle.com,
chris.hyser@...cle.com, Aubrey Li <aubrey.li@...ux.intel.com>,
"Paul E. McKenney" <paulmck@...nel.org>,
Tim Chen <tim.c.chen@...el.com>
Subject: [PATCH v8 -tip 26/26] sched: Debug bits...
From: Peter Zijlstra <peterz@...radead.org>
Tested-by: Julien Desfossez <jdesfossez@...italocean.com>
Not-Signed-off-by: Peter Zijlstra (Intel) <peterz@...radead.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
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