Dave Hansen wrote:
On Thu, 2007-07-26 at 18:51 +0400, Pavel Emelyanov wrote:
+extern struct task_struct *find_task_by_pid_type_ns(int type, int pid,
+ struct pid_namespace *ns);
+
+#define find_task_by_pid_ns(nr, ns) \
+ find_task_by_pid_type_ns(PIDTYPE_PID, nr, ns)
+#define find_task_by_pid_type(type, nr) \
+ find_task_by_pid_type_ns(type, nr, &init_pid_ns)
+#define find_task_by_pid(nr) \
+ find_task_by_pid_type(PIDTYPE_PID, nr)
+
extern void __set_special_pids(pid_t session, pid_t pgrp);
Do these _have_ to be macros?
No, but why not?
I can make them static inline functions, but why are macros that bad?
/* per-UID process charging. */
diff -upr linux-2.6.23-rc1-mm1.orig/kernel/pid.c
linux-2.6.23-rc1-mm1-7/kernel/pid.c
--- linux-2.6.23-rc1-mm1.orig/kernel/pid.c 2007-07-26 16:34:45.000000000
+0400
+++ linux-2.6.23-rc1-mm1-7/kernel/pid.c 2007-07-26 16:36:37.000000000 +0400
@@ -204,19 +221,20 @@ static void delayed_put_pid(struct rcu_h
goto out;
}
-struct pid * fastcall find_pid(int nr)
+struct pid * fastcall find_pid_ns(int nr, struct pid_namespace *ns)
{
struct hlist_node *elem;
- struct pid *pid;
+ struct upid *pnr;
+
+ hlist_for_each_entry_rcu(pnr, elem,
+ &pid_hash[pid_hashfn(nr, ns)], pid_chain)
+ if (pnr->nr == nr && pnr->ns == ns)
+ return container_of(pnr, struct pid,
+ numbers[ns->level]);
Do we do this loop anywhere else? Should we have a for_each_pid() that
makes this a little less messy?
No. Iteration over the hash chain happens here only.
- hlist_for_each_entry_rcu(pid, elem,
- &pid_hash[pid_hashfn(nr)], pid_chain) {
- if (pid->nr == nr)
- return pid;
- }
return NULL;
}
-EXPORT_SYMBOL_GPL(find_pid);
+EXPORT_SYMBOL_GPL(find_pid_ns);
/*
* attach_pid() must be called with the tasklist_lock write-held.
@@ -318,12 +355,13 @@ struct task_struct * fastcall pid_task(s
/*
* Must be called under rcu_read_lock() or with tasklist_lock read-held.
*/
-struct task_struct *find_task_by_pid_type(int type, int nr)
+struct task_struct *find_task_by_pid_type_ns(int type, int nr,
+ struct pid_namespace *ns)
{
- return pid_task(find_pid(nr), type);
+ return pid_task(find_pid_ns(nr, ns), type);
}
-EXPORT_SYMBOL(find_task_by_pid_type);
+EXPORT_SYMBOL(find_task_by_pid_type_ns);
struct pid *get_task_pid(struct task_struct *task, enum pid_type type)
{
@@ -342,7 +426,7 @@ struct pid *find_get_pid(pid_t nr)
struct pid *pid;
rcu_read_lock();
- pid = get_pid(find_pid(nr));
+ pid = get_pid(find_vpid(nr));
rcu_read_unlock();
OK, I think this is really confusing. If find_get_pid() finds vpids,
should we not call it find_get_vpid()?
I'd better make it find_get_pid_ns() with two arguments and made a couple
of macros (or static inlines) for global search and local search.
-- Dave
Thanks,
Pavel
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