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authorPeter Zijlstra <a.p.zijlstra@chello.nl>2010-06-16 14:37:10 +0200
committerIngo Molnar <mingo@elte.hu>2010-09-09 20:46:30 +0200
commita4eaf7f14675cb512d69f0c928055e73d0c6d252 (patch)
treee8a0f631fc28d4bd9becd2e9e2c71743c64ee3ec /kernel/trace/trace_event_perf.c
parentfa407f35e0298d841e4088f95a7f9cf6e725c6d5 (diff)
perf: Rework the PMU methods
Replace pmu::{enable,disable,start,stop,unthrottle} with pmu::{add,del,start,stop}, all of which take a flags argument. The new interface extends the capability to stop a counter while keeping it scheduled on the PMU. We replace the throttled state with the generic stopped state. This also allows us to efficiently stop/start counters over certain code paths (like IRQ handlers). It also allows scheduling a counter without it starting, allowing for a generic frozen state (useful for rotating stopped counters). The stopped state is implemented in two different ways, depending on how the architecture implemented the throttled state: 1) We disable the counter: a) the pmu has per-counter enable bits, we flip that b) we program a NOP event, preserving the counter state 2) We store the counter state and ignore all read/overflow events Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: paulus <paulus@samba.org> Cc: stephane eranian <eranian@googlemail.com> Cc: Robert Richter <robert.richter@amd.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Cyrill Gorcunov <gorcunov@gmail.com> Cc: Lin Ming <ming.m.lin@intel.com> Cc: Yanmin <yanmin_zhang@linux.intel.com> Cc: Deng-Cheng Zhu <dengcheng.zhu@gmail.com> Cc: David Miller <davem@davemloft.net> Cc: Michael Cree <mcree@orcon.net.nz> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/trace/trace_event_perf.c')
-rw-r--r--kernel/trace/trace_event_perf.c7
1 files changed, 5 insertions, 2 deletions
diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c
index f3bbcd1c90c8..39c059ca670e 100644
--- a/kernel/trace/trace_event_perf.c
+++ b/kernel/trace/trace_event_perf.c
@@ -101,7 +101,7 @@ int perf_trace_init(struct perf_event *p_event)
return ret;
}
-int perf_trace_enable(struct perf_event *p_event)
+int perf_trace_add(struct perf_event *p_event, int flags)
{
struct ftrace_event_call *tp_event = p_event->tp_event;
struct hlist_head __percpu *pcpu_list;
@@ -111,13 +111,16 @@ int perf_trace_enable(struct perf_event *p_event)
if (WARN_ON_ONCE(!pcpu_list))
return -EINVAL;
+ if (!(flags & PERF_EF_START))
+ p_event->hw.state = PERF_HES_STOPPED;
+
list = this_cpu_ptr(pcpu_list);
hlist_add_head_rcu(&p_event->hlist_entry, list);
return 0;
}
-void perf_trace_disable(struct perf_event *p_event)
+void perf_trace_del(struct perf_event *p_event, int flags)
{
hlist_del_rcu(&p_event->hlist_entry);
}