From: David Carrillo-Cisneros <davidcc@google.com>
To: linux-kernel@vger.kernel.org
Cc: "x86@kernel.org" <x86@kernel.org>, Ingo Molnar <mingo@redhat.com>,
Thomas Gleixner <tglx@linutronix.de>,
Andi Kleen <ak@linux.intel.com>, Kan Liang <kan.liang@intel.com>,
Peter Zijlstra <peterz@infradead.org>,
Borislav Petkov <bp@suse.de>,
Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>,
Dave Hansen <dave.hansen@linux.intel.com>,
Vikas Shivappa <vikas.shivappa@linux.intel.com>,
Mark Rutland <mark.rutland@arm.com>,
Arnaldo Carvalho de Melo <acme@kernel.org>,
Vince Weaver <vince@deater.net>, Paul Turner <pjt@google.com>,
Stephane Eranian <eranian@google.com>,
David Carrillo-Cisneros <davidcc@google.com>
Subject: [RFC 4/6] perf/core: avoid rb-tree traversal when no inactive events
Date: Tue, 10 Jan 2017 02:25:00 -0800 [thread overview]
Message-ID: <20170110102502.106187-5-davidcc@google.com> (raw)
In-Reply-To: <20170110102502.106187-1-davidcc@google.com>
Avoid unnecessary rb-tree queries.
Signed-off-by: David Carrillo-Cisneros <davidcc@google.com>
---
include/linux/perf_event.h | 2 ++
kernel/events/core.c | 17 +++++++++++++++--
2 files changed, 17 insertions(+), 2 deletions(-)
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index fd32ecc37d33..2e0c94a770e2 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -748,6 +748,8 @@ struct perf_event_context {
struct list_head event_list;
int nr_events;
int nr_active;
+ int nr_inactive_pinned;
+ int nr_inactive_flexible;
int is_active;
int nr_stat;
int nr_freq;
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 302f13ca75dc..c7715b2627a9 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -1531,6 +1531,10 @@ rbtree_add_inactive(struct perf_event *event,
/* Add new node and rebalance tree. */
rb_link_node(&event->rbtree_node, parent, pos);
rb_insert_color(&event->rbtree_node, &ctx->rbtree_root);
+ if (event->attr.pinned)
+ ctx->nr_inactive_pinned++;
+ else
+ ctx->nr_inactive_flexible++;
}
static void
@@ -1754,6 +1758,11 @@ static void ctx_sched_groups_del(struct perf_event *group,
WARN_ON(group->state != PERF_EVENT_STATE_INACTIVE);
rb_erase(&group->rbtree_node, &ctx->rbtree_root);
list_del_init(&group->ctx_active_entry);
+ if (group->attr.pinned)
+ ctx->nr_inactive_pinned--;
+ else
+ ctx->nr_inactive_flexible--;
+
}
/*
@@ -2142,6 +2151,10 @@ ctx_sched_groups_to_active(struct perf_event *event, struct perf_event_context *
WARN_ON(event->state != PERF_EVENT_STATE_ACTIVE);
rb_erase(&event->rbtree_node, &ctx->rbtree_root);
list_move_tail(&event->ctx_active_entry, h);
+ if (event->attr.pinned)
+ ctx->nr_inactive_pinned--;
+ else
+ ctx->nr_inactive_flexible--;
}
static int
@@ -3371,11 +3384,11 @@ ctx_sched_in(struct perf_event_context *ctx,
* First go through the list and put on any pinned groups
* in order to give them the best chance of going on.
*/
- if (is_active & EVENT_PINNED)
+ if (is_active & EVENT_PINNED && ctx->nr_inactive_pinned)
ctx_pinned_sched_in(ctx, cpuctx);
/* Then walk through the lower prio flexible groups */
- if (is_active & EVENT_FLEXIBLE)
+ if (is_active & EVENT_FLEXIBLE && ctx->nr_inactive_flexible)
ctx_flexible_sched_in(ctx, cpuctx);
}
--
2.11.0.390.gc69c2f50cf-goog
next prev parent reply other threads:[~2017-01-10 10:26 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-01-10 10:24 [RFC 0/6] optimize ctx switch with rb-tree David Carrillo-Cisneros
2017-01-10 10:24 ` [RFC 1/6] perf/core: create active and inactive event groups David Carrillo-Cisneros
2017-01-10 13:49 ` Mark Rutland
2017-01-10 20:45 ` David Carrillo-Cisneros
2017-01-12 11:05 ` Mark Rutland
[not found] ` <CALcN6mhPmpSqKhE3Ua+j-xROLzeAyrgdCk4AGGtfF9kExXRTJg@mail.gmail.com>
2017-01-13 11:01 ` Mark Rutland
2017-01-10 10:24 ` [RFC 2/6] perf/core: add a rb-tree index to inactive_groups David Carrillo-Cisneros
2017-01-10 14:14 ` Mark Rutland
2017-01-10 20:20 ` David Carrillo-Cisneros
2017-01-12 11:47 ` Mark Rutland
2017-01-13 7:34 ` David Carrillo-Cisneros
2017-01-16 2:03 ` [lkp-developer] [perf/core] 33da94bd89: BUG:unable_to_handle_kernel kernel test robot
2017-01-10 10:24 ` [RFC 3/6] perf/core: use rb-tree to sched in event groups David Carrillo-Cisneros
2017-01-10 16:38 ` Mark Rutland
2017-01-10 20:51 ` David Carrillo-Cisneros
2017-01-12 12:14 ` Mark Rutland
2017-01-13 8:01 ` David Carrillo-Cisneros
2017-01-13 10:24 ` Mark Rutland
2017-01-11 20:31 ` Liang, Kan
2017-01-12 10:11 ` Mark Rutland
2017-01-12 13:28 ` Liang, Kan
2017-01-13 8:05 ` David Carrillo-Cisneros
2017-01-10 10:25 ` David Carrillo-Cisneros [this message]
2017-01-10 10:25 ` [RFC 5/6] perf/core: rotation no longer necessary. Behavior has changed. Beware David Carrillo-Cisneros
2017-01-10 10:25 ` [RFC 6/6] perf/core: use rb-tree index to optimize filtered perf_iterate_ctx David Carrillo-Cisneros
2017-01-16 2:05 ` [lkp-developer] [perf/core] 49c04ee1a7: WARNING:at_kernel/events/core.c:#perf_iterate_ctx_matching kernel test robot
2017-04-25 17:27 ` [RFC 0/6] optimize ctx switch with rb-tree Liang, Kan
2017-04-25 17:49 ` David Carrillo-Cisneros
2017-04-25 18:11 ` Budankov, Alexey
2017-04-25 18:54 ` David Carrillo-Cisneros
2017-04-26 10:34 ` Budankov, Alexey
2017-04-26 19:40 ` David Carrillo-Cisneros
2017-04-26 10:52 ` Mark Rutland
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