Commit-ID: f988e71bc6220d8b404dbd43c0e0962e30305795 Gitweb: https://git.kernel.org/tip/f988e71bc6220d8b404dbd43c0e0962e30305795 Author: Kan Liang <kan.li...@intel.com> AuthorDate: Fri, 29 Sep 2017 07:47:53 -0700 Committer: Arnaldo Carvalho de Melo <a...@redhat.com> CommitDate: Tue, 3 Oct 2017 09:27:36 -0300
perf tools: Lock to protect comm_str rb tree Add comm_str_lock to protect comm_str rb tree. The lock is only needed for multithreaded code, so using mutex wrappers provided by perf tool. Signed-off-by: Kan Liang <kan.li...@intel.com> Acked-by: Jiri Olsa <jo...@kernel.org> Cc: Adrian Hunter <adrian.hun...@intel.com> Cc: Alexei Starovoitov <a...@kernel.org> Cc: Andi Kleen <a...@linux.intel.com> Cc: He Kuang <heku...@huawei.com> Cc: Lukasz Odzioba <lukasz.odzi...@intel.com> Cc: Namhyung Kim <namhy...@kernel.org> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Wang Nan <wangn...@huawei.com> Link: http://lkml.kernel.org/r/1506696477-146932-3-git-send-email-kan.li...@intel.com Signed-off-by: Arnaldo Carvalho de Melo <a...@redhat.com> --- tools/perf/util/comm.c | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-) diff --git a/tools/perf/util/comm.c b/tools/perf/util/comm.c index 7bc981b..756a9c1 100644 --- a/tools/perf/util/comm.c +++ b/tools/perf/util/comm.c @@ -5,6 +5,7 @@ #include <stdio.h> #include <string.h> #include <linux/refcount.h> +#include "rwsem.h" struct comm_str { char *str; @@ -14,6 +15,7 @@ struct comm_str { /* Should perhaps be moved to struct machine */ static struct rb_root comm_str_root; +static struct rw_semaphore comm_str_lock = {.lock = PTHREAD_RWLOCK_INITIALIZER,}; static struct comm_str *comm_str__get(struct comm_str *cs) { @@ -25,7 +27,9 @@ static struct comm_str *comm_str__get(struct comm_str *cs) static void comm_str__put(struct comm_str *cs) { if (cs && refcount_dec_and_test(&cs->refcnt)) { + down_write(&comm_str_lock); rb_erase(&cs->rb_node, &comm_str_root); + up_write(&comm_str_lock); zfree(&cs->str); free(cs); } @@ -50,7 +54,8 @@ static struct comm_str *comm_str__alloc(const char *str) return cs; } -static struct comm_str *comm_str__findnew(const char *str, struct rb_root *root) +static +struct comm_str *__comm_str__findnew(const char *str, struct rb_root *root) { struct rb_node **p = &root->rb_node; struct rb_node *parent = NULL; @@ -81,6 +86,17 @@ static struct comm_str *comm_str__findnew(const char *str, struct rb_root *root) return new; } +static struct comm_str *comm_str__findnew(const char *str, struct rb_root *root) +{ + struct comm_str *cs; + + down_write(&comm_str_lock); + cs = __comm_str__findnew(str, root); + up_write(&comm_str_lock); + + return cs; +} + struct comm *comm__new(const char *str, u64 timestamp, bool exec) { struct comm *comm = zalloc(sizeof(*comm));
