From b0fafc11115938a3215723f37e8e9cc6a94b05b0 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Wed, 10 Dec 2014 15:45:15 -0800 Subject: [PATCH] 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 Cc: Aaron Tomlin Cc: Alexey Dobriyan Cc: "Eric W. Biederman" , Cc: Sterling Alexander Cc: Peter Zijlstra Cc: Roland McGrath Reviewed-by: Paul E. McKenney Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/proc/array.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/fs/proc/array.c b/fs/proc/array.c index 7c8d9aecb070..800e30f8f284 100644 --- a/fs/proc/array.c +++ b/fs/proc/array.c @@ -158,7 +158,7 @@ static inline void task_state(struct seq_file *m, struct pid_namespace *ns, 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 @@ static inline void task_state(struct seq_file *m, struct pid_namespace *ns, 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 @@ static inline void task_state(struct seq_file *m, struct pid_namespace *ns, "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 @@ static inline void task_state(struct seq_file *m, struct pid_namespace *ns, 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++) -- 2.39.5