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[PATCH] pid: simplify pid iterators 

I think it is hardly possible to read the current do_each_task_pid().  The
new version is much simpler and makes the code smaller.

Only the do_each_task_pid change is tested, the do_each_pid_task isn't.

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>
This commit is contained in:
Oleg Nesterov 2006-10-02 02:17:22 -07:00 committed by Linus Torvalds
parent c88be3eb2e
commit d387cae075
1 changed files with 20 additions and 33 deletions
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53
include/linux/pid.h
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@ -102,42 +102,29 @@ static inline pid_t pid_nr(struct pid *pid)
return nr;
}
#define pid_next(task, type) \
((task)->pids[(type)].node.next)
#define pid_next_task(task, type) \
hlist_entry(pid_next(task, type), struct task_struct, \
pids[(type)].node)
#define do_each_task_pid(who, type, task) \
do { \
struct hlist_node *pos___; \
struct pid *pid___ = find_pid(who); \
if (pid___ != NULL) \
hlist_for_each_entry_rcu((task), pos___, \
&pid___->tasks[type], pids[type].node) {
#define while_each_task_pid(who, type, task) \
} \
} while (0)
/* We could use hlist_for_each_entry_rcu here but it takes more arguments
* than the do_each_task_pid/while_each_task_pid. So we roll our own
* to preserve the existing interface.
*/
#define do_each_task_pid(who, type, task) \
if ((task = find_task_by_pid_type(type, who))) { \
prefetch(pid_next(task, type)); \
do {
#define do_each_pid_task(pid, type, task) \
do { \
struct hlist_node *pos___; \
if (pid != NULL) \
hlist_for_each_entry_rcu((task), pos___, \
&pid->tasks[type], pids[type].node) {
#define while_each_task_pid(who, type, task) \
} while (pid_next(task, type) && ({ \
task = pid_next_task(task, type); \
rcu_dereference(task); \
prefetch(pid_next(task, type)); \
1; }) ); \
}
#define do_each_pid_task(pid, type, task) \
if ((task = pid_task(pid, type))) { \
prefetch(pid_next(task, type)); \
do {
#define while_each_pid_task(pid, type, task) \
} while (pid_next(task, type) && ({ \
task = pid_next_task(task, type); \
rcu_dereference(task); \
prefetch(pid_next(task, type)); \
1; }) ); \
}
#define while_each_pid_task(pid, type, task) \
} \
} while (0)
#endif /* _LINUX_PID_H */