a13 author Benjamin Herrenschmidt 1156727857 +1000 committer Paul Mackerras 1156898176 +1000 [POWERPC] Fix performance regression in IRQ radix tree locking When reworking the powerpc irq code, I figured out that we were using the radix tree in a racy way. As a temporary fix, I put a spinlock in there. However, this can have a significant impact on performances. This patch reworks that to use a smarter technique based on the fact that what we need is in fact a rwlock with extremely rare writers (thus optimized for the read path). Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Paul Mackerras όκ»”