perf_counter tools: Add 'perf annotate' feature

Add new perf sub-command to display annotated source code:

$ perf annotate decode_tree_entry

------------------------------------------------
Percent | Source code & Disassembly of /home/mingo/git/git
------------------------------------------------
:
: /home/mingo/git/git: file format elf64-x86-64
:
:
: Disassembly of section .text:
:
: 00000000004a0da0 <decode_tree_entry>:
: *modep = mode;
: return str;
: }
:
: static void decode_tree_entry(struct tree_desc *desc, const char *buf, unsigned long size)
: {
3.82 : 4a0da0: 41 54 push %r12
: const char *path;
: unsigned int mode, len;
:
: if (size < 24 || buf[size - 21])
0.17 : 4a0da2: 48 83 fa 17 cmp $0x17,%rdx
: *modep = mode;
: return str;
: }
:
: static void decode_tree_entry(struct tree_desc *desc, const char *buf, unsigned long size)
: {
0.00 : 4a0da6: 49 89 fc mov %rdi,%r12
0.00 : 4a0da9: 55 push %rbp
3.37 : 4a0daa: 53 push %rbx
: const char *path;
: unsigned int mode, len;
:
: if (size < 24 || buf[size - 21])
0.08 : 4a0dab: 76 73 jbe 4a0e20 <decode_tree_entry+0x80>
0.00 : 4a0dad: 80 7c 16 eb 00 cmpb $0x0,-0x15(%rsi,%rdx,1)
3.48 : 4a0db2: 75 6c jne 4a0e20 <decode_tree_entry+0x80>
: static const char *get_mode(const char *str, unsigned int *modep)
: {
: unsigned char c;
: unsigned int mode = 0;
:
: if (*str == ' ')
1.94 : 4a0db4: 0f b6 06 movzbl (%rsi),%eax
0.39 : 4a0db7: 3c 20 cmp $0x20,%al
0.00 : 4a0db9: 74 65 je 4a0e20 <decode_tree_entry+0x80>
: return NULL;
:
: while ((c = *str++) != ' ') {
0.06 : 4a0dbb: 89 c2 mov %eax,%edx
: if (c < '0' || c > '7')
1.99 : 4a0dbd: 31 ed xor %ebp,%ebp
: unsigned int mode = 0;
:
: if (*str == ' ')
: return NULL;
:
: while ((c = *str++) != ' ') {
1.74 : 4a0dbf: 48 8d 5e 01 lea 0x1(%rsi),%rbx
: if (c < '0' || c > '7')
0.00 : 4a0dc3: 8d 42 d0 lea -0x30(%rdx),%eax
0.17 : 4a0dc6: 3c 07 cmp $0x7,%al
0.00 : 4a0dc8: 76 0d jbe 4a0dd7 <decode_tree_entry+0x37>
0.00 : 4a0dca: eb 54 jmp 4a0e20 <decode_tree_entry+0x80>
0.00 : 4a0dcc: 0f 1f 40 00 nopl 0x0(%rax)
16.57 : 4a0dd0: 8d 42 d0 lea -0x30(%rdx),%eax
0.14 : 4a0dd3: 3c 07 cmp $0x7,%al
0.00 : 4a0dd5: 77 49 ja 4a0e20 <decode_tree_entry+0x80>
: return NULL;
: mode = (mode << 3) + (c - '0');
3.12 : 4a0dd7: 0f b6 c2 movzbl %dl,%eax
: unsigned int mode = 0;
:
: if (*str == ' ')
: return NULL;
:
: while ((c = *str++) != ' ') {
0.00 : 4a0dda: 0f b6 13 movzbl (%rbx),%edx
16.74 : 4a0ddd: 48 83 c3 01 add $0x1,%rbx
: if (c < '0' || c > '7')
: return NULL;
: mode = (mode << 3) + (c - '0');

The first column is the percentage of samples that arrived on that
particular line - relative to the total cost of the function.

Cc: Peter Zijlstra <[e-mail]>
Cc: Mike Galbraith <[e-mail]>
Cc: Paul Mackerras <[e-mail]>
Cc: Arnaldo Carvalho de Melo <[e-mail]>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <[e-mail]>

Documentation/perf_counter/Documentation/perf-annotate.txt

···
 
 NAME
 ----
-perf-annotate - Read perf.data (created by perf record) and annotate functions
+perf-annotate - Read perf.data (created by perf record) and display annotated code
 
 SYNOPSIS
 --------
···
 
 DESCRIPTION
 -----------
-This command displays the performance counter profile information recorded
-via perf record.
+This command reads the input file and displays an annotated version of the
+code. If the object file has debug symbols then the source code will be
+displayed alongside assembly code.
+
+If there is no debug info in the object, then annotated assembly is displayed.
 
 OPTIONS
 -------

Documentation/perf_counter/builtin-annotate.c

···
 static char		const *input_name = "perf.data";
 static char		*vmlinux = NULL;
 
-static char		default_sort_order[] = "comm,dso";
+static char		default_sort_order[] = "comm,symbol";
 static char		*sort_order = default_sort_order;
 
 static int		input;
···
 #define dprintf(x...)	do { if (dump_trace) printf(x); } while (0)
 
 static int		verbose;
-static int		full_paths;
 
 static unsigned long	page_size;
 static unsigned long	mmap_window = 32;
···
 static LIST_HEAD(dsos);
 static struct dso *kernel_dso;
 static struct dso *vdso;
+
 
 static void dsos__add(struct dso *dso)
 {
···
 	return err;
 }
 
-static char __cwd[PATH_MAX];
-static char *cwd = __cwd;
-static int cwdlen;
-
-static int strcommon(const char *pathname)
-{
-	int n = 0;
-
-	while (pathname[n] == cwd[n] && n < cwdlen)
-		++n;
-
-	return n;
-}
-
 struct map {
 	struct list_head node;
 	uint64_t	 start;
···
 
 	if (self != NULL) {
 		const char *filename = event->filename;
-		char newfilename[PATH_MAX];
-
-		if (cwd) {
-			int n = strcommon(filename);
-
-			if (n == cwdlen) {
-				snprintf(newfilename, sizeof(newfilename),
-					 ".%s", filename + n);
-				filename = newfilename;
-			}
-		}
 
 		self->start = event->start;
 		self->end   = event->start + event->len;
···
 	return cmp;
 }
 
-static size_t
-hist_entry__fprintf(FILE *fp, struct hist_entry *self, uint64_t total_samples)
-{
-	struct sort_entry *se;
-	size_t ret;
-
-	if (total_samples) {
-		double percent = self->count * 100.0 / total_samples;
-		char *color = PERF_COLOR_NORMAL;
-
-		/*
-		 * We color high-overhead entries in red, low-overhead
-		 * entries in green - and keep the middle ground normal:
-		 */
-		if (percent >= 5.0)
-			color = PERF_COLOR_RED;
-		if (percent < 0.5)
-			color = PERF_COLOR_GREEN;
-
-		ret = color_fprintf(fp, color, "   %6.2f%%",
-				(self->count * 100.0) / total_samples);
-	} else
-		ret = fprintf(fp, "%12d ", self->count);
-
-	list_for_each_entry(se, &hist_entry__sort_list, list) {
-		fprintf(fp, "  ");
-		ret += se->print(fp, self);
-	}
-
-	ret += fprintf(fp, "\n");
-
-	return ret;
-}
-
 /*
  * collect histogram counts
  */
+static void hist_hit(struct hist_entry *he, uint64_t ip)
+{
+	unsigned int sym_size, offset;
+	struct symbol *sym = he->sym;
+
+	he->count++;
+
+	if (!sym || !sym->hist)
+		return;
+
+	sym_size = sym->end - sym->start;
+	offset = ip - sym->start;
+
+	if (offset >= sym_size)
+		return;
+
+	sym->hist_sum++;
+	sym->hist[offset]++;
+
+	if (verbose >= 3)
+		printf("%p %s: count++ [ip: %p, %08Lx] => %Ld\n",
+			(void *)he->sym->start,
+			he->sym->name,
+			(void *)ip, ip - he->sym->start,
+			sym->hist[offset]);
+}
 
 static int
 hist_entry__add(struct thread *thread, struct map *map, struct dso *dso,
···
 		cmp = hist_entry__cmp(&entry, he);
 
 		if (!cmp) {
-			he->count++;
+			hist_hit(he, ip);
+
 			return 0;
 		}
 
···
 		rb_erase(&n->rb_node, tree);
 		output__insert_entry(n);
 	}
-}
-
-static size_t output__fprintf(FILE *fp, uint64_t total_samples)
-{
-	struct hist_entry *pos;
-	struct sort_entry *se;
-	struct rb_node *nd;
-	size_t ret = 0;
-
-	fprintf(fp, "\n");
-	fprintf(fp, "#\n");
-	fprintf(fp, "# (%Ld samples)\n", (__u64)total_samples);
-	fprintf(fp, "#\n");
-
-	fprintf(fp, "# Overhead");
-	list_for_each_entry(se, &hist_entry__sort_list, list)
-		fprintf(fp, "  %s", se->header);
-	fprintf(fp, "\n");
-
-	fprintf(fp, "# ........");
-	list_for_each_entry(se, &hist_entry__sort_list, list) {
-		int i;
-
-		fprintf(fp, "  ");
-		for (i = 0; i < strlen(se->header); i++)
-			fprintf(fp, ".");
-	}
-	fprintf(fp, "\n");
-
-	fprintf(fp, "#\n");
-
-	for (nd = rb_first(&output_hists); nd; nd = rb_next(nd)) {
-		pos = rb_entry(nd, struct hist_entry, rb_node);
-		ret += hist_entry__fprintf(fp, pos, total_samples);
-	}
-
-	if (!strcmp(sort_order, default_sort_order)) {
-		fprintf(fp, "#\n");
-		fprintf(fp, "# (For more details, try: perf annotate --sort comm,dso,symbol)\n");
-		fprintf(fp, "#\n");
-	}
-	fprintf(fp, "\n");
-
-	return ret;
 }
 
 static void register_idle_thread(void)
···
 	return 0;
 }
 
+static int
+parse_line(FILE *file, struct symbol *sym, uint64_t start, uint64_t len)
+{
+	char *line = NULL, *tmp, *tmp2;
+	unsigned int offset;
+	size_t line_len;
+	__u64 line_ip;
+	int ret;
+	char *c;
+
+	if (getline(&line, &line_len, file) < 0)
+		return -1;
+	if (!line)
+		return -1;
+
+	c = strchr(line, '\n');
+	if (c)
+		*c = 0;
+
+	line_ip = -1;
+	offset = 0;
+	ret = -2;
+
+	/*
+	 * Strip leading spaces:
+	 */
+	tmp = line;
+	while (*tmp) {
+		if (*tmp != ' ')
+			break;
+		tmp++;
+	}
+
+	if (*tmp) {
+		/*
+		 * Parse hexa addresses followed by ':'
+		 */
+		line_ip = strtoull(tmp, &tmp2, 16);
+		if (*tmp2 != ':')
+			line_ip = -1;
+	}
+
+	if (line_ip != -1) {
+		unsigned int hits = 0;
+		double percent = 0.0;
+		char *color = PERF_COLOR_NORMAL;
+
+		offset = line_ip - start;
+		if (offset < len)
+			hits = sym->hist[offset];
+
+		if (sym->hist_sum)
+			percent = 100.0 * hits / sym->hist_sum;
+
+		/*
+		 * We color high-overhead entries in red, low-overhead
+		 * entries in green - and keep the middle ground normal:
+		 */
+		if (percent >= 5.0)
+			color = PERF_COLOR_RED;
+		else {
+			if (percent > 0.5)
+				color = PERF_COLOR_GREEN;
+		}
+
+		color_fprintf(stdout, color, " %7.2f", percent);
+		printf(" :	");
+		color_fprintf(stdout, PERF_COLOR_BLUE, "%s\n", line);
+	} else {
+		if (!*line)
+			printf("         :\n");
+		else
+			printf("         :	%s\n", line);
+	}
+
+	return 0;
+}
+
+static void annotate_sym(struct dso *dso, struct symbol *sym)
+{
+	char *filename = dso->name;
+	uint64_t start, end, len;
+	char command[PATH_MAX*2];
+	FILE *file;
+
+	if (!filename)
+		return;
+	if (dso == kernel_dso)
+		filename = vmlinux;
+
+	printf("\n------------------------------------------------\n");
+	printf(" Percent |	Source code & Disassembly of %s\n", filename);
+	printf("------------------------------------------------\n");
+
+	if (verbose >= 2)
+		printf("annotating [%p] %30s : [%p] %30s\n", dso, dso->name, sym, sym->name);
+
+	start = sym->obj_start;
+	if (!start)
+		start = sym->start;
+
+	end = start + sym->end - sym->start + 1;
+	len = sym->end - sym->start;
+
+	sprintf(command, "objdump --start-address=0x%016Lx --stop-address=0x%016Lx -dS %s", (__u64)start, (__u64)end, filename);
+
+	if (verbose >= 3)
+		printf("doing: %s\n", command);
+
+	file = popen(command, "r");
+	if (!file)
+		return;
+
+	while (!feof(file)) {
+		if (parse_line(file, sym, start, len) < 0)
+			break;
+	}
+
+	pclose(file);
+}
+
+static void find_annotations(void)
+{
+	struct rb_node *nd;
+	struct dso *dso;
+	int count = 0;
+
+	list_for_each_entry(dso, &dsos, node) {
+
+		for (nd = rb_first(&dso->syms); nd; nd = rb_next(nd)) {
+			struct symbol *sym = rb_entry(nd, struct symbol, rb_node);
+
+			if (sym->hist) {
+				annotate_sym(dso, sym);
+				count++;
+			}
+		}
+	}
+
+	if (!count)
+		printf(" Error: symbol '%s' not present amongst the samples.\n", sym_hist_filter);
+}
+
 static int __cmd_annotate(void)
 {
 	int ret, rc = EXIT_FAILURE;
···
 		return EXIT_FAILURE;
 	}
 
-	if (!full_paths) {
-		if (getcwd(__cwd, sizeof(__cwd)) == NULL) {
-			perror("failed to get the current directory");
-			return EXIT_FAILURE;
-		}
-		cwdlen = strlen(cwd);
-	} else {
-		cwd = NULL;
-		cwdlen = 0;
-	}
 remap:
 	buf = (char *)mmap(NULL, page_size * mmap_window, PROT_READ,
 			   MAP_SHARED, input, offset);
···
 
 	collapse__resort();
 	output__resort();
-	output__fprintf(stdout, total);
+
+	find_annotations();
 
 	return rc;
 }
···
 static const struct option options[] = {
 	OPT_STRING('i', "input", &input_name, "file",
 		    "input file name"),
+	OPT_STRING('s', "symbol", &sym_hist_filter, "file",
+		    "symbol to annotate"),
 	OPT_BOOLEAN('v', "verbose", &verbose,
 		    "be more verbose (show symbol address, etc)"),
 	OPT_BOOLEAN('D', "dump-raw-trace", &dump_trace,
 		    "dump raw trace in ASCII"),
 	OPT_STRING('k', "vmlinux", &vmlinux, "file", "vmlinux pathname"),
-	OPT_STRING('s', "sort", &sort_order, "key[,key2...]",
-		   "sort by key(s): pid, comm, dso, symbol. Default: pid,symbol"),
-	OPT_BOOLEAN('P', "full-paths", &full_paths,
-		    "Don't shorten the pathnames taking into account the cwd"),
 	OPT_END()
 };
 
···
 
 	setup_sorting();
 
-	/*
-	 * Any (unrecognized) arguments left?
-	 */
-	if (argc)
+	if (argc) {
+		/*
+		 * Special case: if there's an argument left then assume tha
+		 * it's a symbol filter:
+		 */
+		if (argc > 1)
+			usage_with_options(annotate_usage, options);
+
+		sym_hist_filter = argv[0];
+	}
+
+	if (!sym_hist_filter)
 		usage_with_options(annotate_usage, options);
 
 	setup_pager();

Documentation/perf_counter/util/symbol.c

···
 #include <gelf.h>
 #include <elf.h>
 
+const char *sym_hist_filter;
+
 static struct symbol *symbol__new(uint64_t start, uint64_t len,
-				  const char *name, unsigned int priv_size)
+				  const char *name, unsigned int priv_size,
+				  uint64_t obj_start, int verbose)
 {
 	size_t namelen = strlen(name) + 1;
-	struct symbol *self = malloc(priv_size + sizeof(*self) + namelen);
+	struct symbol *self = calloc(1, priv_size + sizeof(*self) + namelen);
 
-	if (self != NULL) {
-		if (priv_size) {
-			memset(self, 0, priv_size);
-			self = ((void *)self) + priv_size;
-		}
-		self->start = start;
-		self->end   = start + len - 1;
-		memcpy(self->name, name, namelen);
+	if (!self)
+		return NULL;
+
+	if (verbose >= 2)
+		printf("new symbol: %016Lx [%08lx]: %s, hist: %p, obj_start: %p\n",
+			(__u64)start, len, name, self->hist, (void *)obj_start);
+
+	self->obj_start= obj_start;
+	self->hist = NULL;
+	self->hist_sum = 0;
+
+	if (sym_hist_filter && !strcmp(name, sym_hist_filter))
+		self->hist = calloc(sizeof(__u64), len);
+
+	if (priv_size) {
+		memset(self, 0, priv_size);
+		self = ((void *)self) + priv_size;
 	}
+	self->start = start;
+	self->end   = start + len - 1;
+	memcpy(self->name, name, namelen);
 
 	return self;
 }
···
 		 * Well fix up the end later, when we have all sorted.
 		 */
 		sym = symbol__new(start, 0xdead, line + len + 2,
-				  self->sym_priv_size);
+				  self->sym_priv_size, 0, verbose);
 
 		if (sym == NULL)
 			goto out_delete_line;
···
 static int dso__synthesize_plt_symbols(struct  dso *self, Elf *elf,
 				       GElf_Ehdr *ehdr, Elf_Scn *scn_dynsym,
 				       GElf_Shdr *shdr_dynsym,
-				       size_t dynsym_idx)
+				       size_t dynsym_idx, int verbose)
 {
 	uint32_t nr_rel_entries, idx;
 	GElf_Sym sym;
···
 				 "%s@plt", elf_sym__name(&sym, symstrs));
 
 			f = symbol__new(plt_offset, shdr_plt.sh_entsize,
-					sympltname, self->sym_priv_size);
+					sympltname, self->sym_priv_size, 0, verbose);
 			if (!f)
 				return -1;
 
···
 				 "%s@plt", elf_sym__name(&sym, symstrs));
 
 			f = symbol__new(plt_offset, shdr_plt.sh_entsize,
-					sympltname, self->sym_priv_size);
+					sympltname, self->sym_priv_size, 0, verbose);
 			if (!f)
 				return -1;
 
···
 	if (sec_dynsym != NULL) {
 		nr = dso__synthesize_plt_symbols(self, elf, &ehdr,
 						 sec_dynsym, &shdr,
-						 dynsym_idx);
+						 dynsym_idx, verbose);
 		if (nr < 0)
 			goto out_elf_end;
 	}
···
 
 	elf_symtab__for_each_symbol(syms, nr_syms, index, sym) {
 		struct symbol *f;
+		uint64_t obj_start;
 
 		if (!elf_sym__is_function(&sym))
 			continue;
···
 			goto out_elf_end;
 
 		gelf_getshdr(sec, &shdr);
+		obj_start = sym.st_value;
+
 		sym.st_value -= shdr.sh_addr - shdr.sh_offset;
 
 		f = symbol__new(sym.st_value, sym.st_size,
 				elf_sym__name(&sym, symstrs),
-				self->sym_priv_size);
+				self->sym_priv_size, obj_start, verbose);
 		if (!f)
 			goto out_elf_end;
 

Documentation/perf_counter/util/symbol.h

···
 	struct rb_node	rb_node;
 	__u64		start;
 	__u64		end;
+	__u64		obj_start;
+	__u64		hist_sum;
+	__u64		*hist;
 	char		name[0];
 };
 
···
 	struct symbol    *(*find_symbol)(struct dso *, uint64_t ip);
 	char		 name[0];
 };
+
+const char *sym_hist_filter;
 
 typedef int (*symbol_filter_t)(struct dso *self, struct symbol *sym);