perf tools: Rewrite and improve support for kernel modules

Representing modules as struct map entries, backed by a DSO, etc,
using /proc/modules to find where the module is loaded.

DSOs now can have a short and long name, so that in verbose mode we
can show exactly which .ko or vmlinux image was used.

As kernel modules now are a DSO separate from the kernel, we can
ask for just the hits for a particular set of kernel modules, just
like we can do with shared libraries:

[root@doppio linux-2.6-tip]# perf report -n --vmlinux
/home/acme/git/build/tip-recvmmsg/vmlinux --modules --dsos \[drm\] | head -15
    84.58%      13266             Xorg  [k] drm_clflush_pages
     4.02%        630             Xorg  [k] trace_kmalloc.clone.0
     3.95%        619             Xorg  [k] drm_ioctl
     2.07%        324             Xorg  [k] drm_addbufs
     1.68%        263             Xorg  [k] drm_gem_close_ioctl
     0.77%        120             Xorg  [k] drm_setmaster_ioctl
     0.70%        110             Xorg  [k] drm_lastclose
     0.68%        106             Xorg  [k] drm_open
     0.54%         85             Xorg  [k] drm_mm_search_free
[root@doppio linux-2.6-tip]#

Specifying --dsos /lib/modules/2.6.31-tip/kernel/drivers/gpu/drm/drm.ko
would have the same effect. Allowing specifying just 'drm.ko' is left
for another patch.

Processing kallsyms so that per kernel module struct map are
instantiated was also left for another patch. That will allow
removing the module name from each of its symbols.

struct symbol was reduced by removing the ->module backpointer and
moving it (well now the map) to struct symbol_entry in perf top,
that is its only user right now.

The total linecount went down by ~500 lines.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Avi Kivity <avi@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 32 insertions, 41 deletions

diff --git a/tools/perf/builtin-annotate.c b/tools/perf/builtin-annotate.c
index df516dc..7d5a3b1 100644
--- a/tools/perf/builtin-annotate.c
+++ b/tools/perf/builtin-annotate.c
@@ -63,6 +63,7 @@ static void hist_hit(struct hist_entry *he, u64 ip)
 		return;
 
 	sym_size = sym->end - sym->start;
+	ip = he->map->map_ip(he->map, ip);
 	offset = ip - sym->start;
 
 	if (offset >= sym_size)
@@ -80,7 +81,7 @@ static void hist_hit(struct hist_entry *he, u64 ip)
 }
 
 static int
-hist_entry__add(struct thread *thread, struct map *map, struct dso *dso,
+hist_entry__add(struct thread *thread, struct map *map,
 		struct symbol *sym, u64 ip, char level)
 {
 	struct rb_node **p = &hist.rb_node;
@@ -89,7 +90,6 @@ hist_entry__add(struct thread *thread, struct map *map, struct dso *dso,
 	struct hist_entry entry = {
 		.thread	= thread,
 		.map	= map,
-		.dso	= dso,
 		.sym	= sym,
 		.ip	= ip,
 		.level	= level,
@@ -130,10 +130,10 @@ process_sample_event(event_t *event, unsigned long offset, unsigned long head)
 {
 	char level;
 	int show = 0;
-	struct dso *dso = NULL;
 	struct thread *thread;
 	u64 ip = event->ip.ip;
 	struct map *map = NULL;
+	struct symbol *sym = NULL;
 
 	thread = threads__findnew(event->ip.pid, &threads, &last_match);
 
@@ -155,32 +155,35 @@ process_sample_event(event_t *event, unsigned long offset, unsigned long head)
 	if (event->header.misc & PERF_RECORD_MISC_KERNEL) {
 		show = SHOW_KERNEL;
 		level = 'k';
-
-		dso = kernel_dso;
-
-		dump_printf(" ...... dso: %s\n", dso->name);
-
+		sym = kernel_maps__find_symbol(ip, &map);
+		dump_printf(" ...... dso: %s\n",
+			    map ? map->dso->long_name : "<not found>");
 	} else if (event->header.misc & PERF_RECORD_MISC_USER) {
-
 		show = SHOW_USER;
 		level = '.';
-
 		map = thread__find_map(thread, ip);
 		if (map != NULL) {
+got_map:
 			ip = map->map_ip(map, ip);
-			dso = map->dso;
+			sym = map->dso->find_symbol(map->dso, ip);
 		} else {
 			/*
 			 * If this is outside of all known maps,
 			 * and is a negative address, try to look it
 			 * up in the kernel dso, as it might be a
-			 * vsyscall (which executes in user-mode):
+			 * vsyscall or vdso (which executes in user-mode).
+			 *
+			 * XXX This is nasty, we should have a symbol list in
+			 * the "[vdso]" dso, but for now lets use the old
+			 * trick of looking in the whole kernel symbol list.
 			 */
-			if ((long long)ip < 0)
-				dso = kernel_dso;
+			if ((long long)ip < 0) {
+				map = kernel_map;
+				goto got_map;
+			}
 		}
-		dump_printf(" ...... dso: %s\n", dso ? dso->name : "<not found>");
-
+		dump_printf(" ...... dso: %s\n",
+			    map ? map->dso->long_name : "<not found>");
 	} else {
 		show = SHOW_HV;
 		level = 'H';
@@ -188,12 +191,7 @@ process_sample_event(event_t *event, unsigned long offset, unsigned long head)
 	}
 
 	if (show & show_mask) {
-		struct symbol *sym = NULL;
-
-		if (dso)
-			sym = dso->find_symbol(dso, ip);
-
-		if (hist_entry__add(thread, map, dso, sym, ip, level)) {
+		if (hist_entry__add(thread, map, sym, ip, level)) {
 			fprintf(stderr,
 		"problem incrementing symbol count, skipping event\n");
 			return -1;
@@ -313,7 +311,7 @@ process_event(event_t *event, unsigned long offset, unsigned long head)
 }
 
 static int
-parse_line(FILE *file, struct symbol *sym, u64 start, u64 len)
+parse_line(FILE *file, struct symbol *sym, u64 len)
 {
 	char *line = NULL, *tmp, *tmp2;
 	static const char *prev_line;
@@ -363,7 +361,7 @@ parse_line(FILE *file, struct symbol *sym, u64 start, u64 len)
 		const char *color;
 		struct sym_ext *sym_ext = sym->priv;
 
-		offset = line_ip - start;
+		offset = line_ip - sym->start;
 		if (offset < len)
 			hits = sym->hist[offset];
 
@@ -442,7 +440,7 @@ static void free_source_line(struct symbol *sym, int len)
 
 /* Get the filename:line for the colored entries */
 static void
-get_source_line(struct symbol *sym, u64 start, int len, const char *filename)
+get_source_line(struct symbol *sym, int len, const char *filename)
 {
 	int i;
 	char cmd[PATH_MAX * 2];
@@ -467,7 +465,7 @@ get_source_line(struct symbol *sym, u64 start, int len, const char *filename)
 		if (sym_ext[i].percent <= 0.5)
 			continue;
 
-		offset = start + i;
+		offset = sym->start + i;
 		sprintf(cmd, "addr2line -e %s %016llx", filename, offset);
 		fp = popen(cmd, "r");
 		if (!fp)
@@ -519,31 +517,23 @@ static void print_summary(const char *filename)
 
 static void annotate_sym(struct dso *dso, struct symbol *sym)
 {
-	const char *filename = dso->name, *d_filename;
-	u64 start, end, len;
+	const char *filename = dso->long_name, *d_filename;
+	u64 len;
 	char command[PATH_MAX*2];
 	FILE *file;
 
 	if (!filename)
 		return;
-	if (sym->module)
-		filename = sym->module->path;
-	else if (dso == kernel_dso)
-		filename = vmlinux_name;
-
-	start = sym->obj_start;
-	if (!start)
-		start = sym->start;
+
 	if (full_paths)
 		d_filename = filename;
 	else
 		d_filename = basename(filename);
 
-	end = start + sym->end - sym->start + 1;
 	len = sym->end - sym->start;
 
 	if (print_line) {
-		get_source_line(sym, start, len, filename);
+		get_source_line(sym, len, filename);
 		print_summary(filename);
 	}
 
@@ -552,10 +542,11 @@ static void annotate_sym(struct dso *dso, struct symbol *sym)
 	printf("------------------------------------------------\n");
 
 	if (verbose >= 2)
-		printf("annotating [%p] %30s : [%p] %30s\n", dso, dso->name, sym, sym->name);
+		printf("annotating [%p] %30s : [%p] %30s\n",
+		       dso, dso->long_name, sym, sym->name);
 
 	sprintf(command, "objdump --start-address=0x%016Lx --stop-address=0x%016Lx -dS %s|grep -v %s",
-			(u64)start, (u64)end, filename, filename);
+		sym->start, sym->end, filename, filename);
 
 	if (verbose >= 3)
 		printf("doing: %s\n", command);
@@ -565,7 +556,7 @@ static void annotate_sym(struct dso *dso, struct symbol *sym)
 		return;
 
 	while (!feof(file)) {
-		if (parse_line(file, sym, start, len) < 0)
+		if (parse_line(file, sym, len) < 0)
 			break;
 	}