perf symbols: Rename kthreads to kmaps, using another abstraction for it

Using a struct thread instance just to hold the kernel space maps
(vmlinux + modules) is overkill and confuses people trying to
understand the perf symbols abstractions.

The kernel maps are really present in all threads, i.e. the kernel
is a library, not a separate thread.

So introduce the 'map_groups' abstraction and use it for the kernel
maps, now in the kmaps global variable.

It, in turn, will move, together with the threads list to the
perf_file abstraction, so that we can support multiple perf_file
instances, needed by perf diff.

Brainstormed-with: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Frédéric Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <1260550239-5372-1-git-send-email-acme@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 6 insertions, 5 deletions

diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c
index 4dcecafa85dc..ba0de90cd3d4 100644
--- a/tools/perf/util/event.c
+++ b/tools/perf/util/event.c
@@ -254,13 +254,14 @@ void thread__find_addr_location(struct thread *self, u8 cpumode,
                                 struct addr_location *al,
                                 symbol_filter_t filter)
 {
-        struct thread *thread = al->thread = self;
+        struct map_groups *mg = &self->mg;
 
+        al->thread = self;
         al->addr = addr;
 
         if (cpumode & PERF_RECORD_MISC_KERNEL) {
                 al->level = 'k';
-                thread = kthread;
+                mg = kmaps;
         } else if (cpumode & PERF_RECORD_MISC_USER)
                 al->level = '.';
         else {
@@ -270,7 +271,7 @@ void thread__find_addr_location(struct thread *self, u8 cpumode,
                 return;
         }
 try_again:
-        al->map = thread__find_map(thread, type, al->addr);
+        al->map = map_groups__find(mg, type, al->addr);
         if (al->map == NULL) {
                 /*
                  * If this is outside of all known maps, and is a negative
@@ -281,8 +282,8 @@ try_again:
                  * "[vdso]" dso, but for now lets use the old trick of looking
                  * in the whole kernel symbol list.
                  */
-                if ((long long)al->addr < 0 && thread != kthread) {
-                        thread = kthread;
+                if ((long long)al->addr < 0 && mg != kmaps) {
+                        mg = kmaps;
                         goto try_again;
                 }
                 al->sym = NULL;