Re: Sleeping thread not receive signal until it wakes up

From: Luong Ngo
Date: Wed Mar 07 2007 - 19:40:35 EST


On 3/7/07, Lee Revell <rlrevell@xxxxxxxxxxx> wrote:
On 3/7/07, linux-os (Dick Johnson) <linux-os@xxxxxxxxxxxx> wrote:
> Interruptible_sleep_on is interruptible, but for your task to
> actually be awakened and your alarm handler to get some CPU,
> it needs to be scheduled. If the BKL (big kernel lock) is
> held, it won't be scheduled until it is released.

You can schedule while holding the BKL and it will be dropped and reacquired.

Lee



My hardware is PowerPC architecture. Does it have any thing to do with
the kernel locking? Also, I saw CONFIG_LOCK_KERNEL,
CONFIG_PREEMPT_BKL ans CONFIG_SMP in the file
include/linux/smp_lock.h, or CONFIG_PREEMPT in lib/kernel_lock.c and
I don't have any of these macro defined, would that be the reason. I
could not find where these option when running make menuconfig either.


Thanks,
LNgo
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