On Fri, May 10, 2002 at 04:17:29PM -0700, Andrew Morton wrote:
> It was I who put the BKL back into locks.c, much to
> Matthew's disgust...
The disgust was targetted more at removing the abstraction of
locking scheme which I'd put in and having explicit lock_kernel() /
unlock_kernel() calls. I'd used (iirc) acquire_lock() / release_lock()
macros which could have just been redefined.
> The problem was that replacing the BKL with a semaphore
> seriously damaged Apache thoughput on 8-way. Apache
> was using flock()-based synchronisation and replacing
> a spin with a schedule just killed it.
Which says that our semaphores suck, because they don't try to spin for a
bit before scheduling. Of course, your change back was the right thing
to do in the 2.3.late timeframe.
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