Messages in this thread | | | Date | Sat, 31 Dec 2011 13:49:38 -0600 | Subject | Re: [PATCH RFC] IPv6: Avoid taking write lock for /proc/net/ipv6_route | From | Josh Hunt <> |
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On Fri, Dec 30, 2011 at 4:09 PM, David Miller <davem@davemloft.net> wrote: > From: Josh Hunt <joshhunt00@gmail.com> > Date: Wed, 28 Dec 2011 17:23:07 -0600 > >> lock_stat shows taking the write lock is causing the slowdown. Using >> this info I decided to write a version of fib6_clean_all() which >> replaces write_lock_bh(&table->tb6_lock) with >> read_lock_bh(&table->tb6_lock). With this new function I see the same >> results as with my rtnetlink iperf test. I guess my question is what >> am I missing? Is there a reason you need to take the write lock when >> reading the route table to display to proc? > > You're not missing anything, it's just an oversight or laziness. :-) > > I've applied your patch thanks. > > Longer term we should make the ipv6 tree traversals RCU safe just > like net/ipv4/fib_trie.c is. Then we can do away with even the > read locks for read-only traversals. >
Thanks David. Are you aware if anyone has started the work to make IPv6 traversals RCU safe? -- Josh -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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