On Fri, Nov 07, 2014 at 09:14:51PM +0100, Oleg Nesterov wrote: > 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 <[email protected]>
Reviewed-by: Paul E. McKenney <[email protected]> > --- > fs/proc/array.c | 12 ++++++------ > 1 files changed, 6 insertions(+), 6 deletions(-) > > 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 @@ 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++) > -- > 1.5.5.1 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to [email protected] > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
