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perf symbols: Fix dso lookup by long name and missing buildids 

Commit 4598a0a6d2 ("perf symbols: Improve DSO long names lookup speed
with rbtree") Added a tree to lookup dsos by long name.  That tree gets
corrupted whenever a dso long name is changed because the tree is not
updated.

One effect of that is buildid-list does not work with the 'with-hits'
option because dso lookup fails and results in two structs for the same
dso.  The first has the buildid but no hits, the second has hits but no
buildid. e.g.

Before:

  $ tools/perf/perf record ls
  arch     certs    CREDITS  Documentation  firmware  include
  ipc      Kconfig  lib      Makefile       net       REPORTING-BUGS
  scripts  sound    usr      block          COPYING   crypto
  drivers  fs       init     Kbuild         kernel    MAINTAINERS
  mm       README   samples  security       tools     virt
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.012 MB perf.data (11 samples) ]
  $ tools/perf/perf buildid-list
  574da826c66538a8d9060d393a8866289bd06005 [kernel.kallsyms]
  30c94dc66a1fe95180c3d68d2b89e576d5ae213c /lib/x86_64-linux-gnu/libc-2.19.so
  $ tools/perf/perf buildid-list -H
  574da826c66538a8d9060d393a8866289bd06005 [kernel.kallsyms]
  0000000000000000000000000000000000000000 /lib/x86_64-linux-gnu/libc-2.19.so

After:

  $ tools/perf/perf buildid-list -H
  574da826c66538a8d9060d393a8866289bd06005 [kernel.kallsyms]
  30c94dc66a1fe95180c3d68d2b89e576d5ae213c /lib/x86_64-linux-gnu/libc-2.19.so

The fix is to record the root of the tree on the dso so that
dso__set_long_name() can update the tree when the long name changes.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Douglas Hatch <doug.hatch@hp.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Scott J Norton <scott.norton@hp.com>
Cc: Waiman Long <Waiman.Long@hp.com>
Fixes: 4598a0a6d2 ("perf symbols: Improve DSO long names lookup speed with rbtree")
Link: http://lkml.kernel.org/r/1447408112-1920-2-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
hifive-unleashed-5.1
Adrian Hunter 2015-11-13 11:48:30 +02:00 committed by Arnaldo Carvalho de Melo
parent 2059fc7a5a
commit e266a753bf
3 changed files with 19 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

17
tools/perf/util/dso.c
View File

@ -933,6 +933,7 @@ static struct dso *__dso__findlink_by_longname(struct rb_root *root,
/* Add new node and rebalance tree */
rb_link_node(&dso->rb_node, parent, p);
rb_insert_color(&dso->rb_node, root);
dso->root = root;
}
return NULL;
}
@ -945,15 +946,30 @@ static inline struct dso *__dso__find_by_longname(struct rb_root *root,
void dso__set_long_name(struct dso *dso, const char *name, bool name_allocated)
{
struct rb_root *root = dso->root;
if (name == NULL)
return;
if (dso->long_name_allocated)
free((char *)dso->long_name);
if (root) {
rb_erase(&dso->rb_node, root);
/*
* __dso__findlink_by_longname() isn't guaranteed to add it
* back, so a clean removal is required here.
*/
RB_CLEAR_NODE(&dso->rb_node);
dso->root = NULL;
}
dso->long_name = name;
dso->long_name_len = strlen(name);
dso->long_name_allocated = name_allocated;
if (root)
__dso__findlink_by_longname(root, dso, NULL);
}
void dso__set_short_name(struct dso *dso, const char *name, bool name_allocated)
@ -1046,6 +1062,7 @@ struct dso *dso__new(const char *name)
dso->kernel = DSO_TYPE_USER;
dso->needs_swap = DSO_SWAP__UNSET;
RB_CLEAR_NODE(&dso->rb_node);
dso->root = NULL;
INIT_LIST_HEAD(&dso->node);
INIT_LIST_HEAD(&dso->data.open_entry);
pthread_mutex_init(&dso->lock, NULL);

1
tools/perf/util/dso.h
View File

@ -135,6 +135,7 @@ struct dso {
pthread_mutex_t lock;
struct list_head node;
struct rb_node rb_node; /* rbtree node sorted by long name */
struct rb_root *root; /* root of rbtree that rb_node is in */
struct rb_root symbols[MAP__NR_TYPES];
struct rb_root symbol_names[MAP__NR_TYPES];
struct {

1
tools/perf/util/machine.c
View File

@ -91,6 +91,7 @@ static void dsos__purge(struct dsos *dsos)
list_for_each_entry_safe(pos, n, &dsos->head, node) {
RB_CLEAR_NODE(&pos->rb_node);
pos->root = NULL;
list_del_init(&pos->node);
dso__put(pos);
}