softirqs: Free up pf flag PF_KSOFTIRQD

Cleanup patch, freeing up PF_KSOFTIRQD and use per_cpu ksoftirqd pointer
instead, as suggested by Eric Dumazet.

Tested-by: Shaun Ruffell <sruffell@digium.com>
Signed-off-by: Venkatesh Pallipadi <venki@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1292980144-28796-2-git-send-email-venki@google.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Venkatesh Pallipadi 2010-12-21 17:09:00 -08:00 committed by Ingo Molnar
parent f07333bf6e
commit 4dd53d891c
4 changed files with 9 additions and 4 deletions

View File

@ -426,6 +426,13 @@ extern void raise_softirq(unsigned int nr);
*/
DECLARE_PER_CPU(struct list_head [NR_SOFTIRQS], softirq_work_list);
DECLARE_PER_CPU(struct task_struct *, ksoftirqd);
static inline struct task_struct *this_cpu_ksoftirqd(void)
{
return this_cpu_read(ksoftirqd);
}
/* Try to send a softirq to a remote cpu. If this cannot be done, the
* work will be queued to the local cpu.
*/

View File

@ -1715,7 +1715,6 @@ extern void thread_group_times(struct task_struct *p, cputime_t *ut, cputime_t *
/*
* Per process flags
*/
#define PF_KSOFTIRQD 0x00000001 /* I am ksoftirqd */
#define PF_STARTING 0x00000002 /* being created */
#define PF_EXITING 0x00000004 /* getting shut down */
#define PF_EXITPIDONE 0x00000008 /* pi exit done on shut down */

View File

@ -1880,7 +1880,7 @@ void account_system_vtime(struct task_struct *curr)
*/
if (hardirq_count())
__this_cpu_add(cpu_hardirq_time, delta);
else if (in_serving_softirq() && !(curr->flags & PF_KSOFTIRQD))
else if (in_serving_softirq() && curr != this_cpu_ksoftirqd())
__this_cpu_add(cpu_softirq_time, delta);
irq_time_write_end();

View File

@ -54,7 +54,7 @@ EXPORT_SYMBOL(irq_stat);
static struct softirq_action softirq_vec[NR_SOFTIRQS] __cacheline_aligned_in_smp;
static DEFINE_PER_CPU(struct task_struct *, ksoftirqd);
DEFINE_PER_CPU(struct task_struct *, ksoftirqd);
char *softirq_to_name[NR_SOFTIRQS] = {
"HI", "TIMER", "NET_TX", "NET_RX", "BLOCK", "BLOCK_IOPOLL",
@ -721,7 +721,6 @@ static int run_ksoftirqd(void * __bind_cpu)
{
set_current_state(TASK_INTERRUPTIBLE);
current->flags |= PF_KSOFTIRQD;
while (!kthread_should_stop()) {
preempt_disable();
if (!local_softirq_pending()) {