4.4-stable review patch. If anyone has any objections, please let me know.
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From: Eric Dumazet edumazet@google.com
commit c2615cf5a761b32bf74e85bddc223dfff3d9b9f0 upstream.
Put the read-mostly fields in a separate cache line at the beginning of struct netns_frags, to reduce false sharing noticed in inet_frag_kill()
Signed-off-by: Eric Dumazet edumazet@google.com Signed-off-by: David S. Miller davem@davemloft.net [bwh: Backported to 4.4: adjust context] Signed-off-by: Ben Hutchings ben.hutchings@codethink.co.uk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- include/net/inet_frag.h | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-)
--- a/include/net/inet_frag.h +++ b/include/net/inet_frag.h @@ -4,15 +4,16 @@ #include <linux/rhashtable.h>
struct netns_frags { - struct rhashtable rhashtable ____cacheline_aligned_in_smp; - - /* Keep atomic mem on separate cachelines in structs that include it */ - atomic_long_t mem ____cacheline_aligned_in_smp; /* sysctls */ long high_thresh; long low_thresh; int timeout; struct inet_frags *f; + + struct rhashtable rhashtable ____cacheline_aligned_in_smp; + + /* Keep atomic mem on separate cachelines in structs that include it */ + atomic_long_t mem ____cacheline_aligned_in_smp; };
/**