Commit 978410ff authored by Jiri Olsa's avatar Jiri Olsa Committed by Arnaldo Carvalho de Melo
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perf tools: Allow using PERF_RECORD_MMAP2 to synthesize the kernel map 



Allow using PERF_RECORD_MMAP2 to synthesize the kernel map so that we
can use PERF_RECORD_MMAP2 to encode the kernel build id in the following
csets.

It's enabled by a new symbol_conf.buildid_mmap2 bool field, which will
be switchable in following changes.

Signed-off-by: default avatarJiri Olsa <jolsa@kernel.org>
Acked-by: default avatarNamhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Alexei Budankov <abudankov@huawei.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20201214105457.543111-9-jolsa@kernel.org


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 1ca6e802

tools/perf/util/symbol_conf.h

+2 −1
Original line number Diff line number Diff line
@@ -42,7 +42,8 @@ struct symbol_conf { 
			report_block,

			report_individual_block,

			inline_name,

			disable_add2line_warn;

			disable_add2line_warn,

			buildid_mmap2;

	const char	*vmlinux_name,

			*kallsyms_name,

			*source_prefix,

tools/perf/util/synthetic-events.c

+27 −13
Original line number Diff line number Diff line
@@ -991,11 +991,12 @@ static int __perf_event__synthesize_kernel_mmap(struct perf_tool *tool, 
						perf_event__handler_t process,

						struct machine *machine)

{

	size_t size;

	union perf_event *event;

	size_t size = symbol_conf.buildid_mmap2 ?

			sizeof(event->mmap2) : sizeof(event->mmap);

	struct map *map = machine__kernel_map(machine);

	struct kmap *kmap;

	int err;

	union perf_event *event;



	if (map == NULL)

		return -1;
@@ -1009,7 +1010,7 @@ static int __perf_event__synthesize_kernel_mmap(struct perf_tool *tool, 
	 * available use this, and after it is use this as a fallback for older

	 * kernels.

	 */

	event = zalloc((sizeof(event->mmap) + machine->id_hdr_size));

	event = zalloc(size + machine->id_hdr_size);

	if (event == NULL) {

		pr_debug("Not enough memory synthesizing mmap event "

			 "for kernel modules\n");
@@ -1026,6 +1027,18 @@ static int __perf_event__synthesize_kernel_mmap(struct perf_tool *tool, 
		event->header.misc = PERF_RECORD_MISC_GUEST_KERNEL;

	}



	if (symbol_conf.buildid_mmap2) {

		size = snprintf(event->mmap2.filename, sizeof(event->mmap2.filename),

				"%s%s", machine->mmap_name, kmap->ref_reloc_sym->name) + 1;

		size = PERF_ALIGN(size, sizeof(u64));

		event->mmap2.header.type = PERF_RECORD_MMAP2;

		event->mmap2.header.size = (sizeof(event->mmap2) -

				(sizeof(event->mmap2.filename) - size) + machine->id_hdr_size);

		event->mmap2.pgoff = kmap->ref_reloc_sym->addr;

		event->mmap2.start = map->start;

		event->mmap2.len   = map->end - event->mmap.start;

		event->mmap2.pid   = machine->pid;

	} else {

		size = snprintf(event->mmap.filename, sizeof(event->mmap.filename),

				"%s%s", machine->mmap_name, kmap->ref_reloc_sym->name) + 1;

		size = PERF_ALIGN(size, sizeof(u64));
@@ -1036,6 +1049,7 @@ static int __perf_event__synthesize_kernel_mmap(struct perf_tool *tool, 
		event->mmap.start = map->start;

		event->mmap.len   = map->end - event->mmap.start;

		event->mmap.pid   = machine->pid;

	}



	err = perf_tool__process_synth_event(tool, event, machine, process);

	free(event);