From: Stephane Eranian <eranian@google.com>
Date: Thu, 1 Oct 2020 13:57:49 +0000 (-0700)
Subject: perf/core: Add support for PERF_SAMPLE_CODE_PAGE_SIZE
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=995f088efebe;p=linux.git
perf/core: Add support for PERF_SAMPLE_CODE_PAGE_SIZE
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 NMI-safe perf_get_page_size().
For large PEBS, it's very unlikely that the mapping is gone for the
earlier PEBS records. Enable the feature for the large PEBS. The worst
case is that page-size '0' is returned.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201001135749.2804-5-kan.liang@linux.intel.com
---
diff --git a/arch/x86/events/perf_event.h b/arch/x86/events/perf_event.h
index ee2b9b9fc2a50..10032f023fcc2 100644
--- a/arch/x86/events/perf_event.h
+++ b/arch/x86/events/perf_event.h
@@ -132,7 +132,7 @@ struct amd_nb {
PERF_SAMPLE_DATA_SRC | PERF_SAMPLE_IDENTIFIER | \
PERF_SAMPLE_TRANSACTION | PERF_SAMPLE_PHYS_ADDR | \
PERF_SAMPLE_REGS_INTR | PERF_SAMPLE_REGS_USER | \
- PERF_SAMPLE_PERIOD)
+ PERF_SAMPLE_PERIOD | PERF_SAMPLE_CODE_PAGE_SIZE)
#define PEBS_GP_REGS \
((1ULL << PERF_REG_X86_AX) | \
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 7e3785dd27d93..e533b03af053a 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -1035,6 +1035,7 @@ struct perf_sample_data {
u64 phys_addr;
u64 cgroup;
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 cc6ea346e9f99..c2f20ee3124d5 100644
--- a/include/uapi/linux/perf_event.h
+++ b/include/uapi/linux/perf_event.h
@@ -144,8 +144,9 @@ enum perf_event_sample_format {
PERF_SAMPLE_AUX = 1U << 20,
PERF_SAMPLE_CGROUP = 1U << 21,
PERF_SAMPLE_DATA_PAGE_SIZE = 1U << 22,
+ PERF_SAMPLE_CODE_PAGE_SIZE = 1U << 23,
- PERF_SAMPLE_MAX = 1U << 23, /* non-ABI */
+ PERF_SAMPLE_MAX = 1U << 24, /* non-ABI */
__PERF_SAMPLE_CALLCHAIN_EARLY = 1ULL << 63, /* non-ABI; internal use */
};
@@ -898,6 +899,7 @@ enum perf_event_type {
* { u64 size;
* char data[size]; } && PERF_SAMPLE_AUX
* { 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 a796db2f3b579..7f655d19b8c40 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -1898,6 +1898,9 @@ 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;
}
@@ -6945,6 +6948,9 @@ 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 (sample_type & PERF_SAMPLE_AUX) {
perf_output_put(handle, data->aux_size);
@@ -7125,7 +7131,7 @@ 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) {
@@ -7253,6 +7259,9 @@ 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);
+
if (sample_type & PERF_SAMPLE_AUX) {
u64 size;