----- "Arnd Bergmann" <arnd@xxxxxxxx> wrote: > On Wednesday 07 October 2009, John Kacur wrote: > > > > I've been staring at the BKL lock in cpuid_open, and I can't see > what it > > is protecting. However, I may have missed something - even something > > > obvious, so comments are welcome. > > > > Hi John, > > In general, the lock_kernel() calls in any chardev open() file > operation > are the result of the BKL pushdown by Jon Corbet and others, which has > happened > some time last year[1]. I'd assume that the vast majority is not > needed > at all, so these are an easy target for removal. > > Arnd > > [1] http://lkml.indiana.edu/hypermail/linux/kernel/0805.2/0257.html yup - I'm aware of all the hard work that many people put in before I ever looked at this. Thomas asked the -rt folks to have a look at removing the bkl look during the rt-mini summit in Dresden. I was looking for low hanging fruit to get started. The confusion was over what was already implemented in tip/rt/bkl. I merely looked at the latest linus/master build. The result was a good one though, because basically Thomas' work got pushed from tip/rt/bkl into tip/master, and can hopefully be pushed upstream during the next merge window. Even if getting starting means just reviewing what is in rt/bkl and not yet in linus/master, I think that would be positive. I'm sure Thomas will stomp on me if I start to annoy him. :) Thanks John -- To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
