Commit 995f088e authored by Stephane Eranian's avatar Stephane Eranian Committed by Peter Zijlstra
Browse files

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: default avatarKan Liang <kan.liang@linux.intel.com>
Signed-off-by: default avatarStephane Eranian <eranian@google.com>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201001135749.2804-5-kan.liang@linux.intel.com
parent 4cb6a42e

arch/x86/events/perf_event.h

+1 −1
Original line number Diff line number Diff line
@@ -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)    | \

include/linux/perf_event.h

+1 −0
Original line number Diff line number Diff line
@@ -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 */

include/uapi/linux/perf_event.h

+3 −1
Original line number Diff line number Diff line
@@ -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,

kernel/events/core.c

+10 −1
Original line number Diff line number Diff line
@@ -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;