proc: task_state: move the main seq_printf() outside of rcu_read_lock()
task_state() does seq_printf() under rcu_read_lock(), but this is only
needed for task_tgid_nr_ns() and task_numa_group_id(). We can calculate
tgid/ngid and drop rcu lock.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Aaron Tomlin <atomlin@redhat.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>,
Cc: Sterling Alexander <stalexan@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Roland McGrath <roland@hack.frob.com>
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/proc/array.c b/fs/proc/array.c
index 7c8d9ae..800e30f 100644
--- a/fs/proc/array.c
+++ b/fs/proc/array.c
@@ -158,7 +158,7 @@
struct group_info *group_info;
int g;
const struct cred *cred;
- pid_t ppid, tpid;
+ pid_t ppid, tpid, tgid, ngid;
unsigned int max_fds = 0;
rcu_read_lock();
@@ -170,12 +170,16 @@
if (tracer)
tpid = task_pid_nr_ns(tracer, ns);
}
+
+ tgid = task_tgid_nr_ns(p, ns);
+ ngid = task_numa_group_id(p);
cred = get_task_cred(p);
task_lock(p);
if (p->files)
max_fds = files_fdtable(p->files)->max_fds;
task_unlock(p);
+ rcu_read_unlock();
seq_printf(m,
"State:\t%s\n"
@@ -188,10 +192,7 @@
"Gid:\t%d\t%d\t%d\t%d\n"
"FDSize:\t%d\nGroups:\t",
get_task_state(p),
- task_tgid_nr_ns(p, ns),
- task_numa_group_id(p),
- pid_nr_ns(pid, ns),
- ppid, tpid,
+ tgid, ngid, pid_nr_ns(pid, ns), ppid, tpid,
from_kuid_munged(user_ns, cred->uid),
from_kuid_munged(user_ns, cred->euid),
from_kuid_munged(user_ns, cred->suid),
@@ -201,7 +202,6 @@
from_kgid_munged(user_ns, cred->sgid),
from_kgid_munged(user_ns, cred->fsgid),
max_fds);
- rcu_read_unlock();
group_info = cred->group_info;
for (g = 0; g < group_info->ngroups; g++)