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authorStephane Eranian <eranian@google.com>2020-10-01 06:57:49 -0700
committerPeter Zijlstra <peterz@infradead.org>2020-10-29 11:00:39 +0100
commit995f088efebe1eba0282a6ffa12411b37f8990c2 (patch)
tree9e3185b05657e50aa991790dde6d74ba4dd8ee02 /kernel/events
parent4cb6a42e4c4bc1902644eced67563e7405d4588e (diff)
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
Diffstat (limited to 'kernel/events')
-rw-r--r--kernel/events/core.c11
1 files changed, 10 insertions, 1 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c
index a796db2f3b57..7f655d19b8c4 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;