[PATCH 1/5] perf events: add support for realtime clock attribute

From: David Ahern
Date: Sun Mar 20 2011 - 14:55:49 EST


Kernel side plumbing for PERF_SAMPLE_REALTIME.

Signed-off-by: David Ahern <daahern@xxxxxxxxx>
---
include/linux/perf_event.h | 4 +++-
kernel/perf_event.c | 12 ++++++++++++
2 files changed, 15 insertions(+), 1 deletions(-)

diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index f495c01..d64f0fd 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -125,8 +125,9 @@ enum perf_event_sample_format {
PERF_SAMPLE_PERIOD = 1U << 8,
PERF_SAMPLE_STREAM_ID = 1U << 9,
PERF_SAMPLE_RAW = 1U << 10,
+ PERF_SAMPLE_REALTIME = 1U << 11,

- PERF_SAMPLE_MAX = 1U << 11, /* non-ABI */
+ PERF_SAMPLE_MAX = 1U << 12, /* non-ABI */
};

/*
@@ -998,6 +999,7 @@ struct perf_sample_data {
u32 cpu;
u32 reserved;
} cpu_entry;
+ u64 realtime;
u64 period;
struct perf_callchain_entry *callchain;
struct perf_raw_record *raw;
diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index 3472bb1..977a07b 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -903,6 +903,9 @@ static void perf_event__id_header_size(struct perf_event *event)
if (sample_type & PERF_SAMPLE_CPU)
size += sizeof(data->cpu_entry);

+ if (sample_type & PERF_SAMPLE_REALTIME)
+ size += sizeof(data->realtime);
+
event->id_header_size = size;
}

@@ -4016,6 +4019,9 @@ static void __perf_event_header__init_id(struct perf_event_header *header,
data->cpu_entry.cpu = raw_smp_processor_id();
data->cpu_entry.reserved = 0;
}
+
+ if (sample_type & PERF_SAMPLE_REALTIME)
+ data->realtime = ktime_to_ns(ktime_get_real());
}

static void perf_event_header__init_id(struct perf_event_header *header,
@@ -4045,6 +4051,9 @@ static void __perf_event__output_id_sample(struct perf_output_handle *handle,

if (sample_type & PERF_SAMPLE_CPU)
perf_output_put(handle, data->cpu_entry);
+
+ if (sample_type & PERF_SAMPLE_REALTIME)
+ perf_output_put(handle, data->realtime);
}

static void perf_event__output_id_sample(struct perf_event *event,
@@ -4289,6 +4298,9 @@ void perf_output_sample(struct perf_output_handle *handle,
if (sample_type & PERF_SAMPLE_CPU)
perf_output_put(handle, data->cpu_entry);

+ if (sample_type & PERF_SAMPLE_REALTIME)
+ perf_output_put(handle, data->realtime);
+
if (sample_type & PERF_SAMPLE_PERIOD)
perf_output_put(handle, data->period);

--
1.7.4

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/