From 911362c70df5b766c243dc297fadeaced786ffd8 Mon Sep 17 00:00:00 2001 From: Paolo Abeni Date: Fri, 12 Feb 2016 15:43:53 +0100 Subject: 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: 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 Suggested-and-acked-by: Hannes Frederic Sowa Signed-off-by: David S. Miller --- net/Kconfig | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'net/Kconfig') diff --git a/net/Kconfig b/net/Kconfig index 174354618f8a..b80efecfc1a0 100644 --- a/net/Kconfig +++ b/net/Kconfig @@ -392,6 +392,10 @@ config LWTUNNEL weight tunnel endpoint. Tunnel encapsulation parameters are stored with light weight tunnel state associated with fib routes. +config DST_CACHE + bool "dst cache" + default n + endif # if NET # Used by archs to tell that they support BPF_JIT -- cgit v1.2.3-59-g8ed1b