Messages in this thread Patch in this message | | | From | Stephane Eranian <> | Subject | [PATCH v6 1/4] perf: add active_entry list head to struct perf_event | Date | Fri, 8 Nov 2013 20:46:00 +0100 |
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This patch adds a new field to the struct perf_event. It is intended to be used to chain events which are active (enabled). It helps in the hardware layer for PMUs which do not have actual counter restrictions, i.e., free running read-only counters. Active events are chained as opposed to being tracked via the counter they use.
To save space we use a union with hlist_entry as both are mutually exclusive (suggested by Jiri Olsa).
Signed-off-by: Stephane Eranian <eranian@google.com> --- include/linux/perf_event.h | 5 ++++- kernel/events/core.c | 1 + 2 files changed, 5 insertions(+), 1 deletion(-)
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index 2e069d1..8f4a70f 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -319,7 +319,10 @@ struct perf_event { */ struct list_head migrate_entry; - struct hlist_node hlist_entry; + union { + struct hlist_node hlist_entry; + struct list_head active_entry; + }; int nr_siblings; int group_flags; struct perf_event *group_leader; diff --git a/kernel/events/core.c b/kernel/events/core.c index 4dc078d..90dca5c 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -6663,6 +6663,7 @@ perf_event_alloc(struct perf_event_attr *attr, int cpu, INIT_LIST_HEAD(&event->event_entry); INIT_LIST_HEAD(&event->sibling_list); INIT_LIST_HEAD(&event->rb_entry); + INIT_LIST_HEAD(&event->active_entry); init_waitqueue_head(&event->waitq); init_irq_work(&event->pending, perf_pending_event); -- 1.7.9.5
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