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perf maps: Locking tidy up of nr_maps

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After this change maps__nr_maps is only used by tests, existing users
are migrated to maps__empty. Compute maps__empty under the read lock.

Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: K Prateek Nayak <kprateek.nayak@amd.com>
Cc: James Clark <james.clark@arm.com>
Cc: Vincent Whitchurch <vincent.whitchurch@axis.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Colin Ian King <colin.i.king@gmail.com>
Cc: Changbin Du <changbin.du@huawei.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Song Liu <song@kernel.org>
Cc: Leo Yan <leo.yan@linux.dev>
Cc: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Artem Savkov <asavkov@redhat.com>
Cc: bpf@vger.kernel.org
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20240210031746.4057262-7-irogers@google.com
This commit is contained in:
Ian Rogers 2024-02-09 19:17:46 -08:00 committed by Namhyung Kim
parent ff0bd79980
commit 923e4616ec
3 changed files with 11 additions and 5 deletions
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2
tools/perf/util/machine.c
View File

@ -440,7 +440,7 @@ static struct thread *findnew_guest_code(struct machine *machine,
return NULL;
/* Assume maps are set up if there are any */
if (maps__nr_maps(thread__maps(thread)))
if (!maps__empty(thread__maps(thread)))
return thread;
host_thread = machine__find_thread(host_machine, -1, pid);

10
tools/perf/util/maps.c
View File

@ -541,7 +541,13 @@ void maps__remove(struct maps *maps, struct map *map)
bool maps__empty(struct maps *maps)
{
return maps__nr_maps(maps) == 0;
bool res;
down_read(maps__lock(maps));
res = maps__nr_maps(maps) == 0;
up_read(maps__lock(maps));
return res;
}
bool maps__equal(struct maps *a, struct maps *b)
@ -871,7 +877,7 @@ int maps__copy_from(struct maps *dest, struct maps *parent)
parent_maps_by_address = maps__maps_by_address(parent);
n = maps__nr_maps(parent);
if (maps__empty(dest)) {
if (maps__nr_maps(dest) == 0) {
/* No existing mappings so just copy from parent to avoid reallocs in insert. */
unsigned int nr_maps_allocated = RC_CHK_ACCESS(parent)->nr_maps_allocated;
struct map **dest_maps_by_address =

4
tools/perf/util/maps.h
View File

@ -43,8 +43,8 @@ int maps__for_each_map(struct maps *maps, int (*cb)(struct map *map, void *data)
void maps__remove_maps(struct maps *maps, bool (*cb)(struct map *map, void *data), void *data);
struct machine *maps__machine(const struct maps *maps);
unsigned int maps__nr_maps(const struct maps *maps);
refcount_t *maps__refcnt(struct maps *maps);
unsigned int maps__nr_maps(const struct maps *maps); /* Test only. */
refcount_t *maps__refcnt(struct maps *maps); /* Test only. */
#ifdef HAVE_LIBUNWIND_SUPPORT
void *maps__addr_space(const struct maps *maps);