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, 35 insertions, 44 deletions

diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
index c1a54fc8527a..3ed3baf96ffb 100644
--- a/tools/perf/builtin-report.c
+++ b/tools/perf/builtin-report.c
@@ -349,22 +349,17 @@ static int thread__set_comm_adjust(struct thread *self, const char *comm)
 
 
 static struct symbol *
-resolve_symbol(struct thread *thread, struct map **mapp,
-               struct dso **dsop, u64 *ipp)
+resolve_symbol(struct thread *thread, struct map **mapp, u64 *ipp)
 {
-        struct dso *dso = dsop ? *dsop : NULL;
         struct map *map = mapp ? *mapp : NULL;
         u64 ip = *ipp;
 
-        if (!thread)
-                return NULL;
-
-        if (dso)
-                goto got_dso;
-
         if (map)
                 goto got_map;
 
+        if (!thread)
+                return NULL;
+
         map = thread__find_map(thread, ip);
         if (map != NULL) {
                 /*
@@ -379,29 +374,29 @@ resolve_symbol(struct thread *thread, struct map **mapp,
                         *mapp = map;
 got_map:
                 ip = map->map_ip(map, ip);
-
-                dso = map->dso;
         } 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;
+                        if (mapp)
+                                *mapp = map;
+                }
         }
-        dump_printf(" ...... dso: %s\n", dso ? dso->name : "<not found>");
+        dump_printf(" ...... dso: %s\n",
+                    map ? map->dso->long_name : "<not found>");
         dump_printf(" ...... map: %Lx -> %Lx\n", *ipp, ip);
         *ipp  = ip;
 
-        if (dsop)
-                *dsop = dso;
-
-        if (!dso)
-                return NULL;
-got_dso:
-        return dso->find_symbol(dso, ip);
+        return map ? map->dso->find_symbol(map->dso, ip) : NULL;
 }
 
 static int call__match(struct symbol *sym)
@@ -413,7 +408,7 @@ static int call__match(struct symbol *sym)
 }
 
 static struct symbol **
-resolve_callchain(struct thread *thread, struct map *map __used,
+resolve_callchain(struct thread *thread, struct map *map,
                     struct ip_callchain *chain, struct hist_entry *entry)
 {
         u64 context = PERF_CONTEXT_MAX;
@@ -430,8 +425,7 @@ resolve_callchain(struct thread *thread, struct map *map __used,
 
         for (i = 0; i < chain->nr; i++) {
                 u64 ip = chain->ips[i];
-                struct dso *dso = NULL;
-                struct symbol *sym;
+                struct symbol *sym = NULL;
 
                 if (ip >= PERF_CONTEXT_MAX) {
                         context = ip;
@@ -440,17 +434,15 @@ resolve_callchain(struct thread *thread, struct map *map __used,
 
                 switch (context) {
                 case PERF_CONTEXT_HV:
-                        dso = hypervisor_dso;
                         break;
                 case PERF_CONTEXT_KERNEL:
-                        dso = kernel_dso;
+                        sym = kernel_maps__find_symbol(ip, &map);
                         break;
                 default:
+                        sym = resolve_symbol(thread, &map, &ip);
                         break;
                 }
 
-                sym = resolve_symbol(thread, NULL, &dso, &ip);
-
                 if (sym) {
                         if (sort__has_parent && call__match(sym) &&
                             !entry->parent)
@@ -469,7 +461,7 @@ resolve_callchain(struct thread *thread, struct map *map __used,
  */
 
 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, struct ip_callchain *chain,
                 char level, u64 count)
 {
@@ -480,7 +472,6 @@ 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,
@@ -641,7 +632,7 @@ process_sample_event(event_t *event, unsigned long offset, unsigned long head)
 {
         char level;
         int show = 0;
-        struct dso *dso = NULL;
+        struct symbol *sym = NULL;
         struct thread *thread;
         u64 ip = event->ip.ip;
         u64 period = 1;
@@ -700,35 +691,35 @@ process_sample_event(event_t *event, unsigned long offset, unsigned long head)
                 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 (cpumode == PERF_RECORD_MISC_USER) {
 
                 show = SHOW_USER;
                 level = '.';
+                sym = resolve_symbol(thread, &map, &ip);
 
         } else {
                 show = SHOW_HV;
                 level = 'H';
 
-                dso = hypervisor_dso;
-
                 dump_printf(" ...... dso: [hypervisor]\n");
         }
 
         if (show & show_mask) {
-                struct symbol *sym = resolve_symbol(thread, &map, &dso, &ip);
-
-                if (dso_list && (!dso || !dso->name ||
-                                 !strlist__has_entry(dso_list, dso->name)))
+                if (dso_list &&
+                    (!map || !map->dso ||
+                     !(strlist__has_entry(dso_list, map->dso->short_name) ||
+                       (map->dso->short_name != map->dso->long_name &&
+                        strlist__has_entry(dso_list, map->dso->long_name)))))
                         return 0;
 
-                if (sym_list && (!sym || !strlist__has_entry(sym_list, sym->name)))
+                if (sym_list && sym && !strlist__has_entry(sym_list, sym->name))
                         return 0;
 
-                if (hist_entry__add(thread, map, dso, sym, ip, chain, level, period)) {
+                if (hist_entry__add(thread, map, sym, ip,
+                                    chain, level, period)) {
                         eprintf("problem incrementing symbol count, skipping event\n");
                         return -1;
                 }