Messages in this thread | | | Date | Wed, 30 Oct 2013 21:00:28 +0500 | From | Abbas Raza <> | Subject | Re: [PATCH] kthread_bind: don't wait in kthread_bind for presmp initcalls |
| |
Hi,
Any thoughts here please?
Thanks . Abbas Raza
On 09/27/2013 09:47 PM, Abbas Raza wrote: > From: Abbas Raza <Abbas_Raza@mentor.com> > > wait_task_inactive shouldn't be called in __kthread_bind for presmp > initcalls the same way it is done in !SMP case. > > more info here: > http://permalink.gmane.org/gmane.linux.kernel.embedded/4046 > > This patch improves boot time for pre-smp initcalls as given below > > boot time with this patch: > > calling spawn_ksoftirqd+0x0/0x30 @ 1 > initcall spawn_ksoftirqd+0x0/0x30 returned 0 after 0 usecs > > boot time without this patch: > > calling spawn_ksoftirqd+0x0/0x30 @ 1 > initcall spawn_ksoftirqd+0x0/0x30 returned 0 after 19531 usecs > > Signed-off-by: Abbas Raza <Abbas_Raza@mentor.com> > --- > kernel/kthread.c | 14 ++++++++++---- > 1 file changed, 10 insertions(+), 4 deletions(-) > > diff --git a/kernel/kthread.c b/kernel/kthread.c > index 760e86d..28b5c4b 100644 > --- a/kernel/kthread.c > +++ b/kernel/kthread.c > @@ -290,11 +290,17 @@ EXPORT_SYMBOL(kthread_create_on_node); > > static void __kthread_bind(struct task_struct *p, unsigned int cpu, long state) > { > - /* Must have done schedule() in kthread() before we set_task_cpu */ > - if (!wait_task_inactive(p, state)) { > - WARN_ON(1); > - return; > + if (!((num_online_cpus() == 1) && !cpu)) { > + /* > + * Must have done schedule() in kthread() before > + * we set_task_cpu > + */ > + if (!wait_task_inactive(p, state)) { > + WARN_ON(1); > + return; > + } > } > + > /* It's safe because the task is inactive. */ > do_set_cpus_allowed(p, cpumask_of(cpu)); > p->flags |= PF_NO_SETAFFINITY;
| |