Re: Questions about the buffer+page cache in 2.4.0

[Steve Dodd]

On Thu, Jul 27, 2000 at 07:49:50PM +0200, Daniel Phillips wrote:

> So now it's time to start asking questions.  Just jumping in at a place I
> felt I knew pretty well back in 2.2.13, I'm now looking at the 2.4.0 getblk,
> and I see it's changed somewhat.  Finding and removing a block from the free
> list is now bracketed by a spinlock pair.  First question: why do we use
> atomic_set to set the initial buffer use count if this is already protected
> by a spinlock?

Also, I'd /still/ like to know what stops another CPU from adding the buffer
head we were looking for between the call to get_hash_table returning NULL and
insert_into_queues. AFAICS, getblk() isn't always called with the BKL.