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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/hw_breakpoint.c
parentfa407f35e0298d841e4088f95a7f9cf6e725c6d5 (diff)
downloadlinux-a4eaf7f14675cb512d69f0c928055e73d0c6d252.tar.bz2
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/hw_breakpoint.c')
-rw-r--r--kernel/hw_breakpoint.c29
1 files changed, 27 insertions, 2 deletions
diff --git a/kernel/hw_breakpoint.c b/kernel/hw_breakpoint.c
index e9c5cfa1fd20..6f150095cafe 100644
--- a/kernel/hw_breakpoint.c
+++ b/kernel/hw_breakpoint.c
@@ -586,10 +586,35 @@ static int hw_breakpoint_event_init(struct perf_event *bp)
return 0;
}
+static int hw_breakpoint_add(struct perf_event *bp, int flags)
+{
+ if (!(flags & PERF_EF_START))
+ bp->hw.state = PERF_HES_STOPPED;
+
+ return arch_install_hw_breakpoint(bp);
+}
+
+static void hw_breakpoint_del(struct perf_event *bp, int flags)
+{
+ arch_uninstall_hw_breakpoint(bp);
+}
+
+static void hw_breakpoint_start(struct perf_event *bp, int flags)
+{
+ bp->hw.state = 0;
+}
+
+static void hw_breakpoint_stop(struct perf_event *bp, int flags)
+{
+ bp->hw.state = PERF_HES_STOPPED;
+}
+
static struct pmu perf_breakpoint = {
.event_init = hw_breakpoint_event_init,
- .enable = arch_install_hw_breakpoint,
- .disable = arch_uninstall_hw_breakpoint,
+ .add = hw_breakpoint_add,
+ .del = hw_breakpoint_del,
+ .start = hw_breakpoint_start,
+ .stop = hw_breakpoint_stop,
.read = hw_breakpoint_pmu_read,
};