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split the slow path in acct_process() off

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Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2014-05-07 05:12:09 -04:00
parent cdd37e2309
commit e25ff11ff1
1 changed files with 28 additions and 22 deletions
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50
kernel/acct.c
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@ -599,34 +599,35 @@ void acct_collect(long exitcode, int group_dead)
spin_unlock_irq(&current->sighand->siglock);
}
static void acct_process_in_ns(struct pid_namespace *ns)
static void slow_acct_process(struct pid_namespace *ns)
{
struct file *file = NULL;
struct bsd_acct_struct *acct;
for ( ; ns; ns = ns->parent) {
struct file *file = NULL;
struct bsd_acct_struct *acct;
acct = ns->bacct;
/*
* accelerate the common fastpath:
*/
if (!acct || !acct->file)
return;
acct = ns->bacct;
/*
* accelerate the common fastpath:
*/
if (!acct || !acct->file)
continue;
spin_lock(&acct_lock);
file = acct->file;
if (unlikely(!file)) {
spin_lock(&acct_lock);
file = acct->file;
if (unlikely(!file)) {
spin_unlock(&acct_lock);
continue;
}
get_file(file);
spin_unlock(&acct_lock);
return;
}
get_file(file);
spin_unlock(&acct_lock);
do_acct_process(acct, ns, file);
fput(file);
do_acct_process(acct, ns, file);
fput(file);
}
}
/**
* acct_process - now just a wrapper around acct_process_in_ns,
* which in turn is a wrapper around do_acct_process.
* acct_process
*
* handles process accounting for an exiting task
*/
@ -639,6 +640,11 @@ void acct_process(void)
* alive and holds its namespace, which in turn holds
* its parent.
*/
for (ns = task_active_pid_ns(current); ns != NULL; ns = ns->parent)
acct_process_in_ns(ns);
for (ns = task_active_pid_ns(current); ns != NULL; ns = ns->parent) {
struct bsd_acct_struct *acct = ns->bacct;
if (acct && acct->file)
break;
}
if (unlikely(ns))
slow_acct_process(ns);
}