diff options
| author | John Fastabend <john.fastabend@gmail.com> | 2014-09-28 11:52:56 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2014-09-30 01:02:26 -0400 |
| commit | 22e0f8b9322cb1a48b1357e8f4ae6f5a9eca8cfa (patch) | |
| tree | 2c9ef18dca9d9a441d92ea57cf7f7a292f4ceb3f /include | |
| parent | 79cf79abce71eb7dbc40e2f3121048ca5405cb47 (diff) | |
net: sched: make bstats per cpu and estimator RCU safe
In order to run qdisc's without locking statistics and estimators
need to be handled correctly.
To resolve bstats make the statistics per cpu. And because this is
only needed for qdiscs that are running without locks which is not
the case for most qdiscs in the near future only create percpu
stats when qdiscs set the TCQ_F_CPUSTATS flag.
Next because estimators use the bstats to calculate packets per
second and bytes per second the estimator code paths are updated
to use the per cpu statistics.
Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include')
| -rw-r--r-- | include/net/gen_stats.h | 11 | ||||
| -rw-r--r-- | include/net/sch_generic.h | 22 |
2 files changed, 32 insertions, 1 deletions
diff --git a/include/net/gen_stats.h b/include/net/gen_stats.h index ea4271dceff0..ce3c1281f2a0 100644 --- a/include/net/gen_stats.h +++ b/include/net/gen_stats.h @@ -6,6 +6,11 @@ #include <linux/rtnetlink.h> #include <linux/pkt_sched.h> +struct gnet_stats_basic_cpu { + struct gnet_stats_basic_packed bstats; + struct u64_stats_sync syncp; +}; + struct gnet_dump { spinlock_t * lock; struct sk_buff * skb; @@ -27,7 +32,11 @@ int gnet_stats_start_copy_compat(struct sk_buff *skb, int type, spinlock_t *lock, struct gnet_dump *d); int gnet_stats_copy_basic(struct gnet_dump *d, + struct gnet_stats_basic_cpu __percpu *cpu, struct gnet_stats_basic_packed *b); +void __gnet_stats_copy_basic(struct gnet_stats_basic_packed *bstats, + struct gnet_stats_basic_cpu __percpu *cpu, + struct gnet_stats_basic_packed *b); int gnet_stats_copy_rate_est(struct gnet_dump *d, const struct gnet_stats_basic_packed *b, struct gnet_stats_rate_est64 *r); @@ -37,11 +46,13 @@ int gnet_stats_copy_app(struct gnet_dump *d, void *st, int len); int gnet_stats_finish_copy(struct gnet_dump *d); int gen_new_estimator(struct gnet_stats_basic_packed *bstats, + struct gnet_stats_basic_cpu __percpu *cpu_bstats, struct gnet_stats_rate_est64 *rate_est, spinlock_t *stats_lock, struct nlattr *opt); void gen_kill_estimator(struct gnet_stats_basic_packed *bstats, struct gnet_stats_rate_est64 *rate_est); int gen_replace_estimator(struct gnet_stats_basic_packed *bstats, + struct gnet_stats_basic_cpu __percpu *cpu_bstats, struct gnet_stats_rate_est64 *rate_est, spinlock_t *stats_lock, struct nlattr *opt); bool gen_estimator_active(const struct gnet_stats_basic_packed *bstats, diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h index e65b8e0752af..4b9351120fd8 100644 --- a/include/net/sch_generic.h +++ b/include/net/sch_generic.h @@ -6,6 +6,7 @@ #include <linux/rcupdate.h> #include <linux/pkt_sched.h> #include <linux/pkt_cls.h> +#include <linux/percpu.h> #include <net/gen_stats.h> #include <net/rtnetlink.h> @@ -58,6 +59,7 @@ struct Qdisc { * multiqueue device. */ #define TCQ_F_WARN_NONWC (1 << 16) +#define TCQ_F_CPUSTATS 0x20 /* run using percpu statistics */ u32 limit; const struct Qdisc_ops *ops; struct qdisc_size_table __rcu *stab; @@ -83,7 +85,10 @@ struct Qdisc { */ unsigned long state; struct sk_buff_head q; - struct gnet_stats_basic_packed bstats; + union { + struct gnet_stats_basic_packed bstats; + struct gnet_stats_basic_cpu __percpu *cpu_bstats; + } __packed; unsigned int __state; struct gnet_stats_queue qstats; struct rcu_head rcu_head; @@ -487,6 +492,10 @@ static inline int qdisc_enqueue_root(struct sk_buff *skb, struct Qdisc *sch) return qdisc_enqueue(skb, sch) & NET_XMIT_MASK; } +static inline bool qdisc_is_percpu_stats(const struct Qdisc *q) +{ + return q->flags & TCQ_F_CPUSTATS; +} static inline void bstats_update(struct gnet_stats_basic_packed *bstats, const struct sk_buff *skb) @@ -495,6 +504,17 @@ static inline void bstats_update(struct gnet_stats_basic_packed *bstats, bstats->packets += skb_is_gso(skb) ? skb_shinfo(skb)->gso_segs : 1; } +static inline void qdisc_bstats_update_cpu(struct Qdisc *sch, + const struct sk_buff *skb) +{ + struct gnet_stats_basic_cpu *bstats = + this_cpu_ptr(sch->cpu_bstats); + + u64_stats_update_begin(&bstats->syncp); + bstats_update(&bstats->bstats, skb); + u64_stats_update_end(&bstats->syncp); +} + static inline void qdisc_bstats_update(struct Qdisc *sch, const struct sk_buff *skb) { |