@@ -40,18 +40,21 @@ struct inet_frag_queue {
struct inet_frags {
struct hlist_head hash[INETFRAGS_HASHSZ];
- rwlock_t lock;
- u32 rnd;
- int qsize;
+ /* This rwlock is a global lock (seperate per IPv4, IPv6 and
+ * netfilter). Important to keep this on a seperate cacheline.
+ */
+ rwlock_t lock ____cacheline_aligned_in_smp;
int secret_interval;
struct timer_list secret_timer;
+ u32 rnd;
+ int qsize;
unsigned int (*hashfn)(struct inet_frag_queue *);
+ bool (*match)(struct inet_frag_queue *q, void *arg);
void (*constructor)(struct inet_frag_queue *q,
void *arg);
void (*destructor)(struct inet_frag_queue *);
void (*skb_free)(struct sk_buff *);
- bool (*match)(struct inet_frag_queue *q, void *arg);
void (*frag_expire)(unsigned long data);
};
The globally shared rwlock, of struct inet_frags, shares cacheline with the 'rnd' number, which is used by the hash calculations. Fix this, as this obviously is a bad idea, as unnecessary cache-misses will occur when accessing the 'rnd' number. Also small note that, moving function ptr (*match) up in struct, is to avoid it lands on the next cacheline (on 64-bit). Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> --- V2: - Remove comment about cacheline boundary include/net/inet_frag.h | 11 +++++++---- 1 files changed, 7 insertions(+), 4 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