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Subject[PATCH 08/12] perf/core, x86: Add support for PERF_SAMPLE_CODE_PAGE_SIZE
Date
From: Stephane Eranian <eranian@google.com>

When studying code layout, it is useful to capture the page size of the
sampled code address.

Add a new sample type for code page size.
The new sample type requires collecting the ip. The code page size can
be calculated from the IRQ-safe perf_get_page_size().

Only the generic support is covered. The large PEBS will be disabled
with this sample type.

Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
---
include/linux/perf_event.h | 1 +
include/uapi/linux/perf_event.h | 4 +++-
kernel/events/core.c | 11 ++++++++++-
3 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 3f94d0a..3551e20 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -939,6 +939,7 @@ struct perf_sample_data {

u64 phys_addr;
u64 data_page_size;
+ u64 code_page_size;
} ____cacheline_aligned;

/* default value for data source */
diff --git a/include/uapi/linux/perf_event.h b/include/uapi/linux/perf_event.h
index 513c8ae..dc29149 100644
--- a/include/uapi/linux/perf_event.h
+++ b/include/uapi/linux/perf_event.h
@@ -142,8 +142,9 @@ enum perf_event_sample_format {
PERF_SAMPLE_REGS_INTR = 1U << 18,
PERF_SAMPLE_PHYS_ADDR = 1U << 19,
PERF_SAMPLE_DATA_PAGE_SIZE = 1U << 20,
+ PERF_SAMPLE_CODE_PAGE_SIZE = 1U << 21,

- PERF_SAMPLE_MAX = 1U << 21, /* non-ABI */
+ PERF_SAMPLE_MAX = 1U << 22, /* non-ABI */

__PERF_SAMPLE_CALLCHAIN_EARLY = 1ULL << 63, /* non-ABI; internal use */
};
@@ -863,6 +864,7 @@ enum perf_event_type {
* u64 regs[weight(mask)]; } && PERF_SAMPLE_REGS_INTR
* { u64 phys_addr;} && PERF_SAMPLE_PHYS_ADDR
* { u64 data_page_size;} && PERF_SAMPLE_DATA_PAGE_SIZE
+ * { u64 code_page_size;} && PERF_SAMPLE_CODE_PAGE_SIZE
* };
*/
PERF_RECORD_SAMPLE = 9,
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 0ddb9c2..35871cd 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -1754,6 +1754,9 @@ static void __perf_event_header_size(struct perf_event *event, u64 sample_type)
if (sample_type & PERF_SAMPLE_DATA_PAGE_SIZE)
size += sizeof(data->data_page_size);

+ if (sample_type & PERF_SAMPLE_CODE_PAGE_SIZE)
+ size += sizeof(data->code_page_size);
+
event->header_size = size;
}

@@ -6305,6 +6308,9 @@ void perf_output_sample(struct perf_output_handle *handle,
if (sample_type & PERF_SAMPLE_DATA_PAGE_SIZE)
perf_output_put(handle, data->data_page_size);

+ if (sample_type & PERF_SAMPLE_CODE_PAGE_SIZE)
+ perf_output_put(handle, data->code_page_size);
+
if (!event->attr.watermark) {
int wakeup_events = event->attr.wakeup_events;

@@ -6393,7 +6399,7 @@ void perf_prepare_sample(struct perf_event_header *header,

__perf_event_header__init_id(header, data, event);

- if (sample_type & PERF_SAMPLE_IP)
+ if (sample_type & (PERF_SAMPLE_IP | PERF_SAMPLE_CODE_PAGE_SIZE))
data->ip = perf_instruction_pointer(regs);

if (sample_type & PERF_SAMPLE_CALLCHAIN) {
@@ -6502,6 +6508,9 @@ void perf_prepare_sample(struct perf_event_header *header,

if (sample_type & PERF_SAMPLE_DATA_PAGE_SIZE)
data->data_page_size = perf_get_page_size(data->addr);
+
+ if (sample_type & PERF_SAMPLE_CODE_PAGE_SIZE)
+ data->code_page_size = perf_get_page_size(data->ip);
}

static __always_inline void
--
2.7.4
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