Messages in this thread | | | Date | Fri, 14 Jun 2013 17:20:40 +0300 | Subject | Re: [PATCH v3 next/akpm] aio: convert the ioctx list to radix tree | From | Octavian Purdila <> |
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On Wed, Jun 12, 2013 at 10:40 PM, Zach Brown <zab@redhat.com> wrote: >> I've got an alternate approach for fixing this wart in lookup_ioctx()... >> Instead of using an rbtree, just use the reserved id in the ring buffer >> header to index an array pointing the ioctx. It's not finished yet, and >> it needs to be tidied up, but is most of the way there. > > Yeah, that might work. > > Note that the patch wasn't using an rbtree, it was storing the pointer > value in a *radix* which is why single lookups took so long. Presumably > radix was used for RCU lookups. > > Your ring->id trick lets us use RCU with small ints instead of the > context pointer. It might be worth using idr instead of rolling manual > array code. It'd still be much faster than the list, but get rid of the > large alloc, array walking, memcpy(), etc. >
I picked up Ben's patch and incorporated Zach's idea and the first results look promising, as expected. I am going to do a full test with the same workload I've used for rbtree and come back with the results and the patch in a day or so.
Thanks everybody !
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