* Heiko Carstens <heiko.carstens@xxxxxxxxxx> wrote: > This patch set allows to have inlined spinlocks again. > > V2: rewritten from scratch - now also with readable code > > V3: removed macro to generate out-of-line spinlock variants since that > would break ctags. As requested by Arnd Bergmann. > > V4: allow architectures to specify for each lock/unlock variant if > it should be kept out-of-line or inlined. > > V5: simplify ifdefs as pointed out by Linus. Fix architecture compile > breakages caused by this change. > > Linus, Ingo, do you still have objections? Ok, this looks pretty clean. Two small comments. One (small) worry is that the configuration space of this construct: +#define __spin_lock_is_small +#define __read_lock_is_small +#define __write_lock_is_small +#define __spin_lock_bh_is_small +#define __read_lock_bh_is_small +#define __write_lock_bh_is_small +#define __spin_lock_irq_is_small +#define __read_lock_irq_is_small +#define __write_lock_irq_is_small +#define __spin_lock_irqsave_is_small +#define __read_lock_irqsave_is_small +#define __write_lock_irqsave_is_small +#define __spin_trylock_is_small +#define __read_trylock_is_small +#define __write_trylock_is_small +#define __spin_trylock_bh_is_small +#define __spin_unlock_is_small +#define __read_unlock_is_small +#define __write_unlock_is_small +#define __spin_unlock_bh_is_small +#define __read_unlock_bh_is_small +#define __write_unlock_bh_is_small +#define __spin_unlock_irq_is_small +#define __read_unlock_irq_is_small +#define __write_unlock_irq_is_small +#define __spin_unlock_irqrestore_is_small +#define __read_unlock_irqrestore_is_small +#define __write_unlock_irqrestore_is_small Is 2^28. Could we perhaps shape this in a form that makes it 'formally' a manually tuned inlining decision - where we already accept such kind of per function decisions and know how to handle them? I.e. rename it to something like: #define __always_inline__write_unlock_irqrestore That way it fits into our existing forced-inlining attributes (visually and name-space wise), which means the addition of 'inline' or '__forced_inline', or the removal of such attributes. The closer such a special hack is to already existing principles, the better we'll be able to maintain it as the years progress. The other comment i have: you dont seem to have preserved the current auto-inlining of spin_lock() we did before, have you? Without that this patchset causes a (small) performance regression on every architectures but s390. Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
