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authorEric Dumazet <edumazet@google.com>2020-05-02 19:54:19 -0700
committerDavid S. Miller <davem@davemloft.net>2020-05-03 15:50:31 -0700
commit7ba0537c2b534149be288f851900b4cf5aacde48 (patch)
tree4f8a6cce1cb4f0236b5d7dd15e17948f5abffb1d /net/sched
parentdde0a648fc00e2156a3358600c5fbfb3f53256ac (diff)
downloadlinux-7ba0537c2b534149be288f851900b4cf5aacde48.tar.bz2
net_sched: sch_fq: change fq_flow size/layout
sizeof(struct fq_flow) is 112 bytes on 64bit arches. This means that half of them use two cache lines, but 50% use three cache lines. This patch adds cache line alignment, and makes sure that only the first cache line is touched by fq_enqueue(), which is more expensive that fq_dequeue() in general. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/sched')
-rw-r--r--net/sched/sch_fq.c9
1 files changed, 7 insertions, 2 deletions
diff --git a/net/sched/sch_fq.c b/net/sched/sch_fq.c
index bc9ca1ba507b..ced1f987d7e4 100644
--- a/net/sched/sch_fq.c
+++ b/net/sched/sch_fq.c
@@ -66,6 +66,7 @@ static inline struct fq_skb_cb *fq_skb_cb(struct sk_buff *skb)
* in linear list (head,tail), otherwise are placed in a rbtree (t_root).
*/
struct fq_flow {
+/* First cache line : used in fq_gc(), fq_enqueue(), fq_dequeue() */
struct rb_root t_root;
struct sk_buff *head; /* list of skbs for this flow : first skb */
union {
@@ -74,14 +75,18 @@ struct fq_flow {
};
struct rb_node fq_node; /* anchor in fq_root[] trees */
struct sock *sk;
+ u32 socket_hash; /* sk_hash */
int qlen; /* number of packets in flow queue */
+
+/* Second cache line, used in fq_dequeue() */
int credit;
- u32 socket_hash; /* sk_hash */
+ /* 32bit hole on 64bit arches */
+
struct fq_flow *next; /* next pointer in RR lists */
struct rb_node rate_node; /* anchor in q->delayed tree */
u64 time_next_packet;
-};
+} ____cacheline_aligned_in_smp;
struct fq_flow_head {
struct fq_flow *first;