diff options
author | Jakub Kicinski <kuba@kernel.org> | 2023-04-13 07:26:03 +0300 |
---|---|---|
committer | Jakub Kicinski <kuba@kernel.org> | 2023-04-15 04:56:12 +0300 |
commit | b07a2d97ba5ef154fe736aa510e43a3299eee5f8 (patch) | |
tree | eed24e900219327c88caf4b5b5dafa29f74f0bc2 /net/core | |
parent | c11d2e718c792468e67389b506451eddf26c2dac (diff) | |
download | linux-b07a2d97ba5ef154fe736aa510e43a3299eee5f8.tar.xz |
net: skb: plumb napi state thru skb freeing paths
We maintain a NAPI-local cache of skbs which is fed by napi_consume_skb().
Going forward we will also try to cache head and data pages.
Plumb the "are we in a normal NAPI context" information thru
deeper into the freeing path, up to skb_release_data() and
skb_free_head()/skb_pp_recycle(). The "not normal NAPI context"
comes from netpoll which passes budget of 0 to try to reap
the Tx completions but not perform any Rx.
Use "bool napi_safe" rather than bare "int budget",
the further we get from NAPI the more confusing the budget
argument may seem (particularly whether 0 or MAX is the
correct value to pass in when not in NAPI).
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Tested-by: Dragos Tatulea <dtatulea@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net/core')
-rw-r--r-- | net/core/skbuff.c | 38 |
1 files changed, 20 insertions, 18 deletions
diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 78238a13dbcf..2b5a98c5cb49 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -839,7 +839,7 @@ static void skb_clone_fraglist(struct sk_buff *skb) skb_get(list); } -static bool skb_pp_recycle(struct sk_buff *skb, void *data) +static bool skb_pp_recycle(struct sk_buff *skb, void *data, bool napi_safe) { if (!IS_ENABLED(CONFIG_PAGE_POOL) || !skb->pp_recycle) return false; @@ -856,12 +856,12 @@ static void skb_kfree_head(void *head, unsigned int end_offset) kfree(head); } -static void skb_free_head(struct sk_buff *skb) +static void skb_free_head(struct sk_buff *skb, bool napi_safe) { unsigned char *head = skb->head; if (skb->head_frag) { - if (skb_pp_recycle(skb, head)) + if (skb_pp_recycle(skb, head, napi_safe)) return; skb_free_frag(head); } else { @@ -869,7 +869,8 @@ static void skb_free_head(struct sk_buff *skb) } } -static void skb_release_data(struct sk_buff *skb, enum skb_drop_reason reason) +static void skb_release_data(struct sk_buff *skb, enum skb_drop_reason reason, + bool napi_safe) { struct skb_shared_info *shinfo = skb_shinfo(skb); int i; @@ -894,7 +895,7 @@ free_head: if (shinfo->frag_list) kfree_skb_list_reason(shinfo->frag_list, reason); - skb_free_head(skb); + skb_free_head(skb, napi_safe); exit: /* When we clone an SKB we copy the reycling bit. The pp_recycle * bit is only set on the head though, so in order to avoid races @@ -955,11 +956,12 @@ void skb_release_head_state(struct sk_buff *skb) } /* Free everything but the sk_buff shell. */ -static void skb_release_all(struct sk_buff *skb, enum skb_drop_reason reason) +static void skb_release_all(struct sk_buff *skb, enum skb_drop_reason reason, + bool napi_safe) { skb_release_head_state(skb); if (likely(skb->head)) - skb_release_data(skb, reason); + skb_release_data(skb, reason, napi_safe); } /** @@ -973,7 +975,7 @@ static void skb_release_all(struct sk_buff *skb, enum skb_drop_reason reason) void __kfree_skb(struct sk_buff *skb) { - skb_release_all(skb, SKB_DROP_REASON_NOT_SPECIFIED); + skb_release_all(skb, SKB_DROP_REASON_NOT_SPECIFIED, false); kfree_skbmem(skb); } EXPORT_SYMBOL(__kfree_skb); @@ -1027,7 +1029,7 @@ static void kfree_skb_add_bulk(struct sk_buff *skb, return; } - skb_release_all(skb, reason); + skb_release_all(skb, reason, false); sa->skb_array[sa->skb_count++] = skb; if (unlikely(sa->skb_count == KFREE_SKB_BULK_SIZE)) { @@ -1201,7 +1203,7 @@ EXPORT_SYMBOL(consume_skb); void __consume_stateless_skb(struct sk_buff *skb) { trace_consume_skb(skb, __builtin_return_address(0)); - skb_release_data(skb, SKB_CONSUMED); + skb_release_data(skb, SKB_CONSUMED, false); kfree_skbmem(skb); } @@ -1226,7 +1228,7 @@ static void napi_skb_cache_put(struct sk_buff *skb) void __kfree_skb_defer(struct sk_buff *skb) { - skb_release_all(skb, SKB_DROP_REASON_NOT_SPECIFIED); + skb_release_all(skb, SKB_DROP_REASON_NOT_SPECIFIED, true); napi_skb_cache_put(skb); } @@ -1264,7 +1266,7 @@ void napi_consume_skb(struct sk_buff *skb, int budget) return; } - skb_release_all(skb, SKB_CONSUMED); + skb_release_all(skb, SKB_CONSUMED, !!budget); napi_skb_cache_put(skb); } EXPORT_SYMBOL(napi_consume_skb); @@ -1395,7 +1397,7 @@ EXPORT_SYMBOL_GPL(alloc_skb_for_msg); */ struct sk_buff *skb_morph(struct sk_buff *dst, struct sk_buff *src) { - skb_release_all(dst, SKB_CONSUMED); + skb_release_all(dst, SKB_CONSUMED, false); return __skb_clone(dst, src); } EXPORT_SYMBOL_GPL(skb_morph); @@ -2018,9 +2020,9 @@ int pskb_expand_head(struct sk_buff *skb, int nhead, int ntail, if (skb_has_frag_list(skb)) skb_clone_fraglist(skb); - skb_release_data(skb, SKB_CONSUMED); + skb_release_data(skb, SKB_CONSUMED, false); } else { - skb_free_head(skb); + skb_free_head(skb, false); } off = (data + nhead) - skb->head; @@ -6389,12 +6391,12 @@ static int pskb_carve_inside_header(struct sk_buff *skb, const u32 off, skb_frag_ref(skb, i); if (skb_has_frag_list(skb)) skb_clone_fraglist(skb); - skb_release_data(skb, SKB_CONSUMED); + skb_release_data(skb, SKB_CONSUMED, false); } else { /* we can reuse existing recount- all we did was * relocate values */ - skb_free_head(skb); + skb_free_head(skb, false); } skb->head = data; @@ -6529,7 +6531,7 @@ static int pskb_carve_inside_nonlinear(struct sk_buff *skb, const u32 off, skb_kfree_head(data, size); return -ENOMEM; } - skb_release_data(skb, SKB_CONSUMED); + skb_release_data(skb, SKB_CONSUMED, false); skb->head = data; skb->head_frag = 0; |