From e25ff11ff16aba000dfe9e568d867e5142c31f16 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Wed, 7 May 2014 05:12:09 -0400 Subject: [PATCH] split the slow path in acct_process() off Signed-off-by: Al Viro --- kernel/acct.c | 50 ++++++++++++++++++++++++++++---------------------- 1 file changed, 28 insertions(+), 22 deletions(-) diff --git a/kernel/acct.c b/kernel/acct.c index efa891beeaa3..51188603b258 100644 --- a/kernel/acct.c +++ b/kernel/acct.c @@ -599,34 +599,35 @@ void acct_collect(long exitcode, int group_dead) spin_unlock_irq(¤t->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); } -- 2.20.1