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From: Toshiaki Makita <toshiaki.makita1@gmail.com>
To: Alexei Starovoitov <ast@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Martin KaFai Lau <kafai@fb.com>, Song Liu <songliubraving@fb.com>,
	Yonghong Song <yhs@fb.com>,
	"David S. Miller" <davem@davemloft.net>,
	Jakub Kicinski <jakub.kicinski@netronome.com>,
	Jesper Dangaard Brouer <hawk@kernel.org>,
	John Fastabend <john.fastabend@gmail.com>,
	Jamal Hadi Salim <jhs@mojatatu.com>,
	Cong Wang <xiyou.wangcong@gmail.com>,
	Jiri Pirko <jiri@resnulli.us>,
	Pablo Neira Ayuso <pablo@netfilter.org>,
	Jozsef Kadlecsik <kadlec@netfilter.org>,
	Florian Westphal <fw@strlen.de>,
	Pravin B Shelar <pshelar@ovn.org>
Cc: Toshiaki Makita <toshiaki.makita1@gmail.com>,
	netdev@vger.kernel.org, bpf@vger.kernel.org,
	William Tu <u9012063@gmail.com>,
	Stanislav Fomichev <sdf@fomichev.me>
Subject: [RFC PATCH v2 bpf-next 15/15] bpf, hashtab: Compare keys in long
Date: Fri, 18 Oct 2019 13:07:48 +0900	[thread overview]
Message-ID: <20191018040748.30593-16-toshiaki.makita1@gmail.com> (raw)
In-Reply-To: <20191018040748.30593-1-toshiaki.makita1@gmail.com>

memcmp() is generally slow. Compare keys in long if possible.
This improves xdp_flow performance.

Signed-off-by: Toshiaki Makita <toshiaki.makita1@gmail.com>
---
 kernel/bpf/hashtab.c | 27 +++++++++++++++++++++++++--
 1 file changed, 25 insertions(+), 2 deletions(-)

diff --git a/kernel/bpf/hashtab.c b/kernel/bpf/hashtab.c
index 22066a6..8b5ffd4 100644
--- a/kernel/bpf/hashtab.c
+++ b/kernel/bpf/hashtab.c
@@ -417,6 +417,29 @@ static inline struct hlist_nulls_head *select_bucket(struct bpf_htab *htab, u32
 	return &__select_bucket(htab, hash)->head;
 }
 
+/* key1 must be aligned to sizeof long */
+static bool key_equal(void *key1, void *key2, u32 size)
+{
+	/* Check for key1 */
+	BUILD_BUG_ON(!IS_ALIGNED(offsetof(struct htab_elem, key),
+				 sizeof(long)));
+
+	if (IS_ALIGNED((unsigned long)key2 | (unsigned long)size,
+		       sizeof(long))) {
+		unsigned long *lkey1, *lkey2;
+
+		for (lkey1 = key1, lkey2 = key2; size > 0;
+		     lkey1++, lkey2++, size -= sizeof(long)) {
+			if (*lkey1 != *lkey2)
+				return false;
+		}
+
+		return true;
+	}
+
+	return !memcmp(key1, key2, size);
+}
+
 /* this lookup function can only be called with bucket lock taken */
 static struct htab_elem *lookup_elem_raw(struct hlist_nulls_head *head, u32 hash,
 					 void *key, u32 key_size)
@@ -425,7 +448,7 @@ static struct htab_elem *lookup_elem_raw(struct hlist_nulls_head *head, u32 hash
 	struct htab_elem *l;
 
 	hlist_nulls_for_each_entry_rcu(l, n, head, hash_node)
-		if (l->hash == hash && !memcmp(&l->key, key, key_size))
+		if (l->hash == hash && key_equal(&l->key, key, key_size))
 			return l;
 
 	return NULL;
@@ -444,7 +467,7 @@ static struct htab_elem *lookup_nulls_elem_raw(struct hlist_nulls_head *head,
 
 again:
 	hlist_nulls_for_each_entry_rcu(l, n, head, hash_node)
-		if (l->hash == hash && !memcmp(&l->key, key, key_size))
+		if (l->hash == hash && key_equal(&l->key, key, key_size))
 			return l;
 
 	if (unlikely(get_nulls_value(n) != (hash & (n_buckets - 1))))
-- 
1.8.3.1


  parent reply	other threads:[~2019-10-18  5:06 UTC|newest]

Thread overview: 58+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-10-18  4:07 [RFC PATCH v2 bpf-next 00/15] xdp_flow: Flow offload to XDP Toshiaki Makita
2019-10-18  4:07 ` [RFC PATCH v2 bpf-next 01/15] xdp_flow: Add skeleton of XDP based flow offload driver Toshiaki Makita
2019-10-18  4:07 ` [RFC PATCH v2 bpf-next 02/15] xdp_flow: Add skeleton bpf program for XDP Toshiaki Makita
2019-10-18  4:07 ` [RFC PATCH v2 bpf-next 03/15] bpf: Add API to get program from id Toshiaki Makita
2019-10-18  4:07 ` [RFC PATCH v2 bpf-next 04/15] xdp: Export dev_check_xdp and dev_change_xdp Toshiaki Makita
2019-10-18  4:07 ` [RFC PATCH v2 bpf-next 05/15] xdp_flow: Attach bpf prog to XDP in kernel after UMH loaded program Toshiaki Makita
2019-10-18  4:07 ` [RFC PATCH v2 bpf-next 06/15] xdp_flow: Prepare flow tables in bpf Toshiaki Makita
2019-10-18  4:07 ` [RFC PATCH v2 bpf-next 07/15] xdp_flow: Add flow entry insertion/deletion logic in UMH Toshiaki Makita
2019-10-18  4:07 ` [RFC PATCH v2 bpf-next 08/15] xdp_flow: Add flow handling and basic actions in bpf prog Toshiaki Makita
2019-10-18  4:07 ` [RFC PATCH v2 bpf-next 09/15] xdp_flow: Implement flow replacement/deletion logic in xdp_flow kmod Toshiaki Makita
2019-10-18  4:07 ` [RFC PATCH v2 bpf-next 10/15] xdp_flow: Add netdev feature for enabling flow offload to XDP Toshiaki Makita
2019-10-18  4:07 ` [RFC PATCH v2 bpf-next 11/15] xdp_flow: Implement redirect action Toshiaki Makita
2019-10-18  4:07 ` [RFC PATCH v2 bpf-next 12/15] xdp_flow: Implement vlan_push action Toshiaki Makita
2019-10-18  4:07 ` [RFC PATCH v2 bpf-next 13/15] bpf, selftest: Add test for xdp_flow Toshiaki Makita
2019-10-18  4:07 ` [RFC PATCH v2 bpf-next 14/15] i40e: prefetch xdp->data before running XDP prog Toshiaki Makita
2019-10-18  4:07 ` Toshiaki Makita [this message]
2019-10-18 15:22 ` [RFC PATCH v2 bpf-next 00/15] xdp_flow: Flow offload to XDP John Fastabend
2019-10-21  7:31   ` Toshiaki Makita
2019-10-22 16:54     ` John Fastabend
2019-10-22 17:45       ` Toke Høiland-Jørgensen
2019-10-24  4:27         ` John Fastabend
2019-10-24 10:13           ` Toke Høiland-Jørgensen
2019-10-27 13:19             ` Toshiaki Makita
2019-10-27 15:21               ` Toke Høiland-Jørgensen
2019-10-28  3:16                 ` David Ahern
2019-10-28  8:36                   ` Toke Høiland-Jørgensen
2019-10-28 10:08                     ` Jesper Dangaard Brouer
2019-10-28 19:07                       ` David Ahern
2019-10-28 19:05                     ` David Ahern
2019-10-31  0:18                 ` Toshiaki Makita
2019-10-31 12:12                   ` Toke Høiland-Jørgensen
2019-11-11  7:32                     ` Toshiaki Makita
2019-11-12 16:53                       ` Toke Høiland-Jørgensen
2019-11-14 10:11                         ` Toshiaki Makita
2019-11-14 12:41                           ` Toke Høiland-Jørgensen
2019-11-18  6:41                             ` Toshiaki Makita
2019-11-18 10:20                               ` Toke Høiland-Jørgensen
2019-11-22  5:42                                 ` Toshiaki Makita
2019-11-22 11:54                                   ` Toke Høiland-Jørgensen
2019-11-25 10:18                                     ` Toshiaki Makita
2019-11-25 13:03                                       ` Toke Høiland-Jørgensen
2019-11-18 10:28                               ` Toke Høiland-Jørgensen
2019-10-27 13:13         ` Toshiaki Makita
2019-10-27 15:24           ` Toke Høiland-Jørgensen
2019-10-27 19:17             ` David Miller
2019-10-31  0:32               ` Toshiaki Makita
2019-11-12 17:50                 ` William Tu
2019-11-14 10:06                   ` Toshiaki Makita
2019-11-14 17:09                     ` William Tu
2019-11-15 13:16                       ` Toke Høiland-Jørgensen
2019-11-12 17:38             ` William Tu
2019-10-23 14:11       ` Jamal Hadi Salim
2019-10-24  4:38         ` John Fastabend
2019-10-24 17:05           ` Jamal Hadi Salim
2019-10-27 13:27         ` Toshiaki Makita
2019-10-27 13:06       ` Toshiaki Makita
2019-10-21 11:23 ` Björn Töpel
2019-10-21 11:47   ` Toshiaki Makita

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