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| author | Pavel Begunkov <asml.silence@gmail.com> | 2024-04-10 04:28:09 +0300 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2024-04-11 05:27:32 +0300 |
| commit | 7cb31c46b9cc37a5e564667fe46daf9a35dbafdd (patch) | |
| tree | b96f2ea221cdb949f977bf3077e941a7327adbd3 /net/core | |
| parent | 9b9fd45869e744bea7d32a94793736e3d9fd7d26 (diff) | |
| download | linux-7cb31c46b9cc37a5e564667fe46daf9a35dbafdd.tar.xz | |
net: cache for same cpu skb_attempt_defer_free
Optimise skb_attempt_defer_free() when run by the same CPU the skb was
allocated on. Instead of __kfree_skb() -> kmem_cache_free() we can
disable softirqs and put the buffer into cpu local caches.
CPU bound TCP ping pong style benchmarking (i.e. netbench) showed a 1%
throughput increase (392.2 -> 396.4 Krps). Cross checking with profiles,
the total CPU share of skb_attempt_defer_free() dropped by 0.6%. Note,
I'd expect the win doubled with rx only benchmarks, as the optimisation
is for the receive path, but the test spends >55% of CPU doing writes.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/a887463fb219d973ec5ad275e31194812571f1f5.1712711977.git.asml.silence@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net/core')
| -rw-r--r-- | net/core/skbuff.c | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 888874ef8566..18612f255ef5 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -6974,6 +6974,19 @@ free_now: EXPORT_SYMBOL(__skb_ext_put); #endif /* CONFIG_SKB_EXTENSIONS */ +static void kfree_skb_napi_cache(struct sk_buff *skb) +{ + /* if SKB is a clone, don't handle this case */ + if (skb->fclone != SKB_FCLONE_UNAVAILABLE) { + __kfree_skb(skb); + return; + } + + local_bh_disable(); + __napi_kfree_skb(skb, SKB_DROP_REASON_NOT_SPECIFIED); + local_bh_enable(); +} + /** * skb_attempt_defer_free - queue skb for remote freeing * @skb: buffer @@ -6992,7 +7005,7 @@ void skb_attempt_defer_free(struct sk_buff *skb) if (WARN_ON_ONCE(cpu >= nr_cpu_ids) || !cpu_online(cpu) || cpu == raw_smp_processor_id()) { -nodefer: __kfree_skb(skb); +nodefer: kfree_skb_napi_cache(skb); return; } |