On Sat, 1 Apr 2006, Alex Izvorski wrote: > Dean - I think I see what you mean, you're looking at this line in the > assembly? > > 65830 16.8830 : c1f: cmp %rcx,0x28(%rax) yup that's the one... that's probably a fair number of cache (or tlb) misses going on right there. > I looked at the hash stuff, I think the problem is not that the hash > function is poor, but rather that the number of entries in all buckets > gets to be pretty high. yeah... your analysis seems more likely. i suppose increasing the number of buckets is the only option. it looks to me like you'd just need to change NR_HASH and the kzalloc in run() in order to increase the number of buckets. i'm guessing there's a good reason for STRIPE_SIZE being 4KiB -- 'cause otherwise it'd be cool to run with STRIPE_SIZE the same as your raid chunksize... which would decrease the number of entries -- much more desirable than increasing the number of buckets. -dean - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
