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| author |   Eric Dumazet <edumazet@google.com> | 2025-04-07 16:35:59 +0000 |
|---|---|---|
| committer |   Jakub Kicinski <kuba@kernel.org> | 2025-04-08 12:30:55 -0700 |
| commit | c3025e94daa9ce84ef0e53df983b5bf2fbd76ea6 (patch) | |
| tree | ae27369d8f8e2ba0f96e7038fa7a996d7d9c8d28 /net/core/dev.c | |
| parent | amd-xgbe: Convert to SPDX identifier (diff) | |
| download | wireguard-linux-c3025e94daa9ce84ef0e53df983b5bf2fbd76ea6.tar.xz wireguard-linux-c3025e94daa9ce84ef0e53df983b5bf2fbd76ea6.zip | |
net: rps: change skb_flow_limit() hash function
As explained in commit f3483c8e1da6 ("net: rfs: hash function change"),
masking low order bits of skb_get_hash(skb) has low entropy.
A NIC with 32 RX queues uses the 5 low order bits of rss key
to select a queue. This means all packets landing to a given
queue share the same 5 low order bits.
Switch to hash_32() to reduce hash collisions.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20250407163602.170356-2-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net/core/dev.c')
| -rw-r--r-- | net/core/dev.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/net/core/dev.c b/net/core/dev.c index 0608605cfc24..f674236f34be 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -5038,7 +5038,7 @@ static bool skb_flow_limit(struct sk_buff *skb, unsigned int qlen) rcu_read_lock(); fl = rcu_dereference(sd->flow_limit); if (fl) { - new_flow = skb_get_hash(skb) & (fl->num_buckets - 1); + new_flow = hash_32(skb_get_hash(skb), fl->log_buckets); old_flow = fl->history[fl->history_head]; fl->history[fl->history_head] = new_flow; |