From: Stephane Eranian Date: Tue, 12 Nov 2013 16:58:48 +0000 (+0100) Subject: perf: Add active_entry list head to struct perf_event X-Git-Tag: v4.9.8~7132^2~23 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=71ad88efebbcde374bddf904b96f3a7fc82d45d4;p=platform%2Fkernel%2Flinux-rpi3.git perf: Add active_entry list head to struct perf_event 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 Reviewed-by: Andi Kleen Signed-off-by: Peter Zijlstra Cc: acme@redhat.com Cc: jolsa@redhat.com Cc: zheng.z.yan@intel.com Cc: bp@alien8.de Cc: maria.n.dimakopoulou@gmail.com Link: http://lkml.kernel.org/r/1384275531-10892-2-git-send-email-eranian@google.com Signed-off-by: Ingo Molnar --- 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 72348dc..403b781 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -6655,6 +6655,7 @@ 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);