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    SubjectRe: [PATCH RFC] IPv6: Avoid taking write lock for /proc/net/ipv6_route
    On Fri, Dec 30, 2011 at 4:09 PM, David Miller <> wrote:
    > From: Josh Hunt <>
    > 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?
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      Last update: 2011-12-31 20:53    [W:0.025 / U:37.272 seconds]
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