On Thu, Jul 7, 2016 at 6:04 PM, Jesse Gross <je...@kernel.org> wrote: > On Thu, Jul 7, 2016 at 5:23 PM, Pravin B Shelar <pshe...@ovn.org> wrote: >> This backports dst-cache implementation from upstream implementation. >> >> commit 911362c70df5b766c243dc297fadeaced786ffd8 >> Author: Paolo Abeni <pab...@redhat.com> >> >> net: add dst_cache support >> This patch add a generic, lockless dst cache implementation. >> The need for lock is avoided updating the dst cache fields >> only in per cpu scope, and requiring that the cache manipulation >> functions are invoked with the local bh disabled. >> >> The refresh_ts and reset_ts fields are used to ensure the cache >> consistency in case of cuncurrent cache update (dst_cache_set*) and >> reset operation (dst_cache_reset). >> >> Consider the following scenario: >> >> CPU1: CPU2: >> <cache lookup with emtpy cache: it fails> >> <get dst via uncached route lookup> >> <related configuration >> changes> >> dst_cache_reset() >> dst_cache_set() >> >> The dst entry set passed to dst_cache_set() should not be used >> for later dst cache lookup, because it's obtained using old >> configuration values. >> >> Since the refresh_ts is updated only on dst_cache lookup, the >> cached value in the above scenario will be discarded on the next >> lookup. >> >> Signed-off-by: Paolo Abeni <pab...@redhat.com> >> Suggested-and-acked-by: Hannes Frederic Sowa <han...@stressinduktion.org> >> Signed-off-by: David S. Miller <da...@davemloft.net> >> >> Signed-off-by: Pravin B Shelar <pshe...@ovn.org> >> Acked-by: Jesse Gross <je...@kernel.org> > > I saw in the big Geneve/VXLAN backport patch that USE_UPSTREAM_TUNNEL > becomes dependent on having the dst cache. That's fine but I couldn't > find anywhere that prevents the reverse - continuing to use our > version of the dst cache when we have upstream tunnels (the functions > here look like unconditional replacements). It seems like that will > create a problem in a couple weeks when 4.7 is released.
As discussed I am planing on doing it later when I add support for new kernel. I can not test it without compiling it with new kernel. _______________________________________________ dev mailing list dev@openvswitch.org http://openvswitch.org/mailman/listinfo/dev
