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net: cacheline adjust struct inet_frags for better frag performance

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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>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Jesper Dangaard Brouer 2013-01-28 23:44:37 +00:00 committed by David S. Miller
parent cd39a7890a
commit 5f8e1e8b76
1 changed files with 7 additions and 4 deletions
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11
include/net/inet_frag.h
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@ -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);
};