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Commit 80d496be authored by Pekka Enberg's avatar Pekka Enberg Committed by Ingo Molnar
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perf report: Add support for profiling JIT generated code 



This patch adds support for profiling JIT generated code to 'perf
report'. A JIT compiler is required to generate a "/tmp/perf-$PID.map"
symbols map that is parsed when looking and displaying symbols.

Thanks to Peter Zijlstra for his help with this patch!

Example "perf report" output with the Jato JIT:

 #
 # (40311 samples)
 #
 # Overhead           Command  Shared Object              Symbol
 # ........  ................  .........................  ......
 #
     97.80%              jato  /tmp/perf-11915.map        [.] Fibonacci.fib(I)I
      0.56%              jato  00000000b7fa023b           0x000000b7fa023b
      0.45%              jato  /tmp/perf-11915.map        [.] Fibonacci.main([Ljava/lang/String;)V
      0.38%              jato  [kernel]                   [k] get_page_from_freelist
      0.06%              jato  [kernel]                   [k] kunmap_atomic
      0.05%              jato  ./jato                     [.] utf8Hash
      0.04%              jato  ./jato                     [.] executeJava
      0.04%              jato  ./jato                     [.] defineClass

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: default avatarPekka Enberg <penberg@cs.helsinki.fi>
Cc: a.p.zijlstra@chello.nl
Cc: acme@redhat.com
LKML-Reference: <Pine.LNX.4.64.0906082111590.12407@melkki.cs.Helsinki.FI>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent dab5855b

tools/perf/builtin-report.c

+14 −1
Original line number Diff line number Diff line
@@ -209,6 +209,11 @@ static uint64_t vdso__map_ip(struct map *map, uint64_t ip) 
	return ip;

}



static inline int is_anon_memory(const char *filename)

{

     return strcmp(filename, "//anon") == 0;

}



static struct map *map__new(struct mmap_event *event)

{

	struct map *self = malloc(sizeof(*self));
@@ -216,6 +221,7 @@ static struct map *map__new(struct mmap_event *event) 
	if (self != NULL) {

		const char *filename = event->filename;

		char newfilename[PATH_MAX];

		int anon;



		if (cwd) {

			int n = strcommon(filename);
@@ -227,6 +233,13 @@ static struct map *map__new(struct mmap_event *event) 
			}

		}



		anon = is_anon_memory(filename);



		if (anon) {

			snprintf(newfilename, sizeof(newfilename), "/tmp/perf-%d.map", event->pid);

			filename = newfilename;

		}



		self->start = event->start;

		self->end   = event->start + event->len;

		self->pgoff = event->pgoff;
@@ -235,7 +248,7 @@ static struct map *map__new(struct mmap_event *event) 
		if (self->dso == NULL)

			goto out_delete;



		if (self->dso == vdso)

		if (self->dso == vdso || anon)

			self->map_ip = vdso__map_ip;

		else

			self->map_ip = map__map_ip;

tools/perf/util/symbol.c

+65 −0
Original line number Diff line number Diff line
@@ -220,6 +220,68 @@ static int dso__load_kallsyms(struct dso *self, symbol_filter_t filter, int verb 
	return -1;

}



static int dso__load_perf_map(struct dso *self, symbol_filter_t filter, int verbose)

{

	char *line = NULL;

	size_t n;

	FILE *file;

	int nr_syms = 0;



	file = fopen(self->name, "r");

	if (file == NULL)

		goto out_failure;



	while (!feof(file)) {

		__u64 start, size;

		struct symbol *sym;

		int line_len, len;



		line_len = getline(&line, &n, file);

		if (line_len < 0)

			break;



		if (!line)

			goto out_failure;



		line[--line_len] = '\0'; /* \n */



		len = hex2u64(line, &start);



		len++;

		if (len + 2 >= line_len)

			continue;



		len += hex2u64(line + len, &size);



		len++;

		if (len + 2 >= line_len)

			continue;



		sym = symbol__new(start, size, line + len,

				  self->sym_priv_size, start, verbose);



		if (sym == NULL)

			goto out_delete_line;



		if (filter && filter(self, sym))

			symbol__delete(sym, self->sym_priv_size);

		else {

			dso__insert_symbol(self, sym);

			nr_syms++;

		}

	}



	free(line);

	fclose(file);



	return nr_syms;



out_delete_line:

	free(line);

out_failure:

	return -1;

}



/**

 * elf_symtab__for_each_symbol - iterate thru all the symbols

 *
@@ -507,6 +569,9 @@ int dso__load(struct dso *self, symbol_filter_t filter, int verbose) 
	if (!name)

		return -1;



	if (strncmp(self->name, "/tmp/perf-", 10) == 0)

		return dso__load_perf_map(self, filter, verbose);



more:

	do {

		switch (variant) {