Messages in this thread | | | Date | Thu, 21 Jun 2018 15:50:14 +0200 | From | Ingo Molnar <> | Subject | Re: [PATCH] semaphore: use raw_spin_lock_irq instead of raw_spin_lock_irqsave |
| |
* Mikulas Patocka <mpatocka@redhat.com> wrote:
> The sleeping functions down, down_interruptible, down_killable and > down_timeout can't be called with interrupts disabled, so we don't have to > save and restore interrupt flag. > > This patch avoids the costly pushf and popf instructions on the semaphore > path. > > Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> > > --- > kernel/locking/semaphore.c | 21 ++++++++------------- > 1 file changed, 8 insertions(+), 13 deletions(-)
I've applied this to the locking tree, I suspect we can do this on the condition that it doesn't explode in early boot code (which has irqs disabled) and doesn't generate early boot lockdep splats either.
Thanks,
Ingo
| |