| Message ID | 20130129094406.13513.80799.stgit@dragon |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
diff --git a/include/net/inet_frag.h b/include/net/inet_frag.h index 32786a0..91e7797 100644 --- a/include/net/inet_frag.h +++ b/include/net/inet_frag.h @@ -3,9 +3,12 @@ struct netns_frags { int nqueues; - atomic_t mem; struct list_head lru_list; + /* Its important for performance to keep lru_list and mem on + * separate cachelines + */ + atomic_t mem ____cacheline_aligned_in_smp; /* sysctls */ int timeout; int high_thresh;
This small cacheline adjustment of struct netns_frags improves performance significantly for the fragmentation code. Struct members 'lru_list' and 'mem' are both hot elements, and it hurts performance, due to cacheline bouncing at every call point, when they share a cacheline. Also notice, how mem is placed together with 'high_thresh' and 'low_thresh', as they are used in the compare operations together. Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> --- include/net/inet_frag.h | 5 ++++- 1 files changed, 4 insertions(+), 1 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html