diff options
| author | Paolo Abeni <pabeni@redhat.com> | 2018-05-25 16:28:44 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2018-05-28 23:13:39 -0400 |
| commit | e9be0e993d95adbe5efe0e0f03b2a3e71f5bb2b6 (patch) | |
| tree | 59c29c303e00e10e68efc5c048f1bd1b239ec12e /include/net | |
| parent | 102cd909635612c0be784a519651954a7924c786 (diff) | |
net: sched: shrink struct Qdisc
The struct Qdisc has a lot of holes, especially after commit
a53851e2c321 ("net: sched: explicit locking in gso_cpu fallback"),
which as a side effect, moved the fields just after 'busylock'
on a new cacheline.
Since both 'padded' and 'refcnt' are not updated frequently, and
there is a hole before 'gso_skb', we can move such fields there,
saving a cacheline without any performance side effect.
Before this commit:
pahole -C Qdisc net/sche/sch_generic.o
# ...
/* size: 384, cachelines: 6, members: 25 */
/* sum members: 236, holes: 3, sum holes: 92 */
/* padding: 56 */
After this commit:
pahole -C Qdisc net/sche/sch_generic.o
# ...
/* size: 320, cachelines: 5, members: 25 */
/* sum members: 236, holes: 2, sum holes: 28 */
/* padding: 56 */
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/net')
| -rw-r--r-- | include/net/sch_generic.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h index 98c10a28cd01..827a3711dc68 100644 --- a/include/net/sch_generic.h +++ b/include/net/sch_generic.h @@ -85,6 +85,8 @@ struct Qdisc { struct net_rate_estimator __rcu *rate_est; struct gnet_stats_basic_cpu __percpu *cpu_bstats; struct gnet_stats_queue __percpu *cpu_qstats; + int padded; + refcount_t refcnt; /* * For performance sake on SMP, we put highly modified fields at the end @@ -97,8 +99,6 @@ struct Qdisc { unsigned long state; struct Qdisc *next_sched; struct sk_buff_head skb_bad_txq; - int padded; - refcount_t refcnt; spinlock_t busylock ____cacheline_aligned_in_smp; spinlock_t seqlock; |