bpf: compute hashes in bloom filter similar to hashmap

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If the value size in a bloom filter is a multiple of 4, then the jhash2()
function is used to compute hashes. The length parameter of this function
equals to the number of 32-bit words in input. Compute it in the hot path
instead of pre-computing it, as this is translated to one extra shift to
divide the length by four vs. one extra memory load of a pre-computed length.

Signed-off-by: Anton Protopopov <aspsk@isovalent.com>
Link: https://lore.kernel.org/r/20230402114340.3441-1-aspsk@isovalent.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

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Anton Protopopov 2023-04-02 11:43:40 +00:00 • committed by Alexei Starovoitov

parent 5b85575ad4

commit 92b2e810f0

1 changed files with 2 additions and 15 deletions

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kernel/bpf/bloom_filter.c

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