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| author | Pavankumar Kondeti <pkondeti@codeaurora.org> | 2017-06-21 09:22:45 +0530 |
|---|---|---|
| committer | Amit Pundir <amit.pundir@linaro.org> | 2018-08-28 17:10:42 +0530 |
| commit | aab728ca5f823bd65c41940dcbc3bcead4a727b7 (patch) | |
| tree | 59b3128c204d625f7c5192bed4d39b94ab9778f7 | |
| parent | b8ab1e4c0d49b2165c05e08d912c91791ea17505 (diff) | |
| download | linaro-android-aab728ca5f823bd65c41940dcbc3bcead4a727b7.tar.gz | |
ANDROID: uid_sys_stats: Replace tasklist lock with RCU in uid_cputime_show
Tasklist lock is acuquired in uid_cputime_show for updating the stats
for all tasks in the system. This can potentially disable preemption
for several milli seconds. Replace tasklist_lock with RCU read side
primitives.
Change-Id: Ife69cb577bfdceaae6eb21b9bda09a0fe687e140
Signed-off-by: Pavankumar Kondeti <pkondeti@codeaurora.org>
| -rw-r--r-- | drivers/misc/uid_sys_stats.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/drivers/misc/uid_sys_stats.c b/drivers/misc/uid_sys_stats.c index fbf7db598d55..88dc1cd3a204 100644 --- a/drivers/misc/uid_sys_stats.c +++ b/drivers/misc/uid_sys_stats.c @@ -346,13 +346,13 @@ static int uid_cputime_show(struct seq_file *m, void *v) uid_entry->active_utime = 0; } - read_lock(&tasklist_lock); + rcu_read_lock(); do_each_thread(temp, task) { uid = from_kuid_munged(user_ns, task_uid(task)); if (!uid_entry || uid_entry->uid != uid) uid_entry = find_or_register_uid(uid); if (!uid_entry) { - read_unlock(&tasklist_lock); + rcu_read_unlock(); rt_mutex_unlock(&uid_lock); pr_err("%s: failed to find the uid_entry for uid %d\n", __func__, uid); @@ -362,7 +362,7 @@ static int uid_cputime_show(struct seq_file *m, void *v) uid_entry->active_utime += utime; uid_entry->active_stime += stime; } while_each_thread(temp, task); - read_unlock(&tasklist_lock); + rcu_read_unlock(); hash_for_each(hash_table, bkt, uid_entry, hash) { u64 total_utime = uid_entry->utime + |