Commit 7e49827cc937a742ae02078b483e3eb78f791a2a
Committed by
Linus Torvalds
Linus Torvalds
1 parent
6e1be45aa6
Exists in
master
and in
7 other branches
proc: get_nr_threads() doesn't need ->siglock any longer
Now that task->signal can't go away get_nr_threads() doesn't need ->siglock to read signal->count. Also, make it inline, move into sched.h, and convert 2 other proc users of signal->count to use this (now trivial) helper. Henceforth get_nr_threads() is the only valid user of signal->count, we are ready to turn it into "int nr_threads" or, perhaps, kill it. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: David Howells <dhowells@redhat.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Acked-by: Roland McGrath <roland@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Showing 3 changed files with 7 additions and 14 deletions Side-by-side Diff
fs/proc/array.c
| ... | ... | @@ -267,7 +267,7 @@ |
| 267 | 267 | shpending = p->signal->shared_pending.signal; |
| 268 | 268 | blocked = p->blocked; |
| 269 | 269 | collect_sigign_sigcatch(p, &ignored, &caught); |
| 270 | - num_threads = atomic_read(&p->signal->count); | |
| 270 | + num_threads = get_nr_threads(p); | |
| 271 | 271 | rcu_read_lock(); /* FIXME: is this correct? */ |
| 272 | 272 | qsize = atomic_read(&__task_cred(p)->user->sigpending); |
| 273 | 273 | rcu_read_unlock(); |
| ... | ... | @@ -410,7 +410,7 @@ |
| 410 | 410 | tty_nr = new_encode_dev(tty_devnum(sig->tty)); |
| 411 | 411 | } |
| 412 | 412 | |
| 413 | - num_threads = atomic_read(&sig->count); | |
| 413 | + num_threads = get_nr_threads(task); | |
| 414 | 414 | collect_sigign_sigcatch(task, &sigign, &sigcatch); |
| 415 | 415 | |
| 416 | 416 | cmin_flt = sig->cmin_flt; |
fs/proc/base.c
| ... | ... | @@ -166,18 +166,6 @@ |
| 166 | 166 | return result; |
| 167 | 167 | } |
| 168 | 168 | |
| 169 | -static int get_nr_threads(struct task_struct *tsk) | |
| 170 | -{ | |
| 171 | - unsigned long flags; | |
| 172 | - int count = 0; | |
| 173 | - | |
| 174 | - if (lock_task_sighand(tsk, &flags)) { | |
| 175 | - count = atomic_read(&tsk->signal->count); | |
| 176 | - unlock_task_sighand(tsk, &flags); | |
| 177 | - } | |
| 178 | - return count; | |
| 179 | -} | |
| 180 | - | |
| 181 | 169 | static int proc_cwd_link(struct inode *inode, struct path *path) |
| 182 | 170 | { |
| 183 | 171 | struct task_struct *task = get_proc_task(inode); |
include/linux/sched.h
| ... | ... | @@ -2147,6 +2147,11 @@ |
| 2147 | 2147 | #define while_each_thread(g, t) \ |
| 2148 | 2148 | while ((t = next_thread(t)) != g) |
| 2149 | 2149 | |
| 2150 | +static inline int get_nr_threads(struct task_struct *tsk) | |
| 2151 | +{ | |
| 2152 | + return atomic_read(&tsk->signal->count); | |
| 2153 | +} | |
| 2154 | + | |
| 2150 | 2155 | /* de_thread depends on thread_group_leader not being a pid based check */ |
| 2151 | 2156 | #define thread_group_leader(p) (p == p->group_leader) |
| 2152 | 2157 |