On 02.09.2015 23:32, James Bottomley wrote: > On Wed, 2015-09-02 at 21:38 +0200, Helge Deller wrote: >> Align the locks for the Light weight syscall (LWS) which is used for >> atomic userspace operations (e.g. gcc atomic builtins) on L1 cache >> boundaries. This should speed up LWS calls on PA20 systems. > > Is there any evidence for this? The architectural requirement for ldcw > on which all this is based is pegged at 16 bytes. This implies that the > burst width on PA88/89 may indeed be 128 bytes, but the coherence width > for operations may still be 16 bytes. If that speculation is true, > there's no speed at all gained by aligning ldcw to 128 bytes and all you > do is waste space. Sure, we'll have to measure timings here... Helge -- To unsubscribe from this list: send the line "unsubscribe linux-parisc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
