On Sat, 2007-04-28 at 09:34 +0100, Christoph Hellwig wrote: > Well, here's my powerpc patch to do the direct call that I sent out > a few weeks ago. It not just speed up the pagefault path a lot, > but also is a major code cleanup. Andi and Anton didn't like it > because they have ambition for murky debugger code to possibly > use it one day.. I thought about using a direct call for s390 as well. The advantage of a direct call is that it avoids the overhead of a notifier call even if kprobes is running. The disadvantage is that there cannot be a second consumer of the fault notifications. I choose the middle way: avoid the overhead if kprobes is not active and use the full notifier if kprobes is running. It should not hurt the performance too badly since kprobe_running is only true if the cpu gets a page fault while executing a kprobe. -- blue skies, Martin. "Reality continues to ruin my life." - Calvin. - To unsubscribe from this list: send the line "unsubscribe linux-s390" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
