On 7/25/06, Gaurav Dhiman < gauravd.chd@xxxxxxxxx> wrote:May I know where you read this. It does not seems ok to me.
I agree with your view point.
Gaurav
Operating system comcepts (7th edition), page 221
On 7/25/06, Grob Team <grobteam@xxxxxxxxx> wrote:
>
> Hi,
>
> I've read that on single-processor machines rather than holding a spinlock,
> the kernel disables kernel preemption (2.6). However, it seems that
> interrupts are still enabled so if an interrupt occured and call the
> function who is suposed to contain the spinlock, we will have data
> consistency problem since the function who has been interrupted was doing
> something in the critical region and the isr is doing something in the
> critical region too. Someone can explain me what I dont understand?
>
> Thank you
>
--
Gaurav
Email: gauravd.chd@xxxxxxxxx
There are quite a few variants of spin locks.
1.spin_lock
spin_unlock
The above ones are used when you know the critical section that
you are protecting will not accessed from an interrupt handler.
In case of uniprocessor m/c these locks are not effective as they
compile away to nothing.
2.spin_lock_irqsave
spin_unlock_irqrestore
These locks also disable the interrrupts.
do refer "kernelsources/Documentation/spinlocks.txt" for further details.
Thank you :)
