diff options
author | Oleg Nesterov <oleg@tv-sign.ru> | 2006-03-29 00:11:07 (GMT) |
---|---|---|
committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-03-29 02:36:41 (GMT) |
commit | 73b9ebfe126a4a886ee46cbab637374d7024668a (patch) | |
tree | d7ba00d4ce76b49c1569334956cd196b35977a04 /kernel/pid.c | |
parent | c97d98931ac52ef110b62d9b75c6a6f2bfbc1898 (diff) | |
download | linux-fsl-qoriq-73b9ebfe126a4a886ee46cbab637374d7024668a.tar.xz |
[PATCH] pidhash: don't count idle threads
fork_idle() does unhash_process() just after copy_process(). Contrary,
boot_cpu's idle thread explicitely registers itself for each pid_type with nr
= 0.
copy_process() already checks p->pid != 0 before process_counts++, I think we
can just skip attach_pid() calls and job control inits for idle threads and
kill unhash_process(). We don't need to cleanup ->proc_dentry in fork_idle()
because with this patch idle threads are never hashed in
kernel/pid.c:pid_hash[].
We don't need to hash pid == 0 in pidmap_init(). free_pidmap() is never
called with pid == 0 arg, so it will never be reused. So it is still possible
to use pid == 0 in any PIDTYPE_xxx namespace from kernel/pid.c's POV.
However with this patch we don't hash pid == 0 for PIDTYPE_PID case. We still
have have PIDTYPE_PGID/PIDTYPE_SID entries with pid == 0: /sbin/init and
kernel threads which don't call daemonize().
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'kernel/pid.c')
-rw-r--r-- | kernel/pid.c | 10 |
1 files changed, 1 insertions, 9 deletions
diff --git a/kernel/pid.c b/kernel/pid.c index 7781d99..a9f2dfd 100644 --- a/kernel/pid.c +++ b/kernel/pid.c @@ -247,16 +247,8 @@ void __init pidhash_init(void) void __init pidmap_init(void) { - int i; - pidmap_array->page = (void *)get_zeroed_page(GFP_KERNEL); + /* Reserve PID 0. We never call free_pidmap(0) */ set_bit(0, pidmap_array->page); atomic_dec(&pidmap_array->nr_free); - - /* - * Allocate PID 0, and hash it via all PID types: - */ - - for (i = 0; i < PIDTYPE_MAX; i++) - attach_pid(current, i, 0); } |