From: "Alexei Starovoitov" <alexei.starovoitov@gmail.com>
To: "Mykyta Yatsenko" <mykyta.yatsenko5@gmail.com>,
<bpf@vger.kernel.org>, <andrii@kernel.org>,
<daniel@iogearbox.net>, <kernel-team@meta.com>,
<eddyz87@gmail.com>, <memxor@gmail.com>
Cc: "Mykyta Yatsenko" <yatsenko@meta.com>
Subject: Re: [PATCH bpf-next] bpf: Speed up htab hashing for u32/u64 keys
Date: Mon, 21 Sep 2026 17:00:30 +0000 [thread overview]
Message-ID: <DLL5LJUBBBNP.K6GOQ6AV8OU0@gmail.com> (raw)
In-Reply-To: <179000542526.3934731.994864591824564797@gmail.com>
On Mon Sep 21, 2026 at 3:43 PM UTC, Alexei Starovoitov wrote:
> > static inline u32 htab_map_hash(const void *key, u32 key_len, u32 hashrnd)
> > {
> > - if (likely(key_len % 4 == 0))
> > + const u32 *k = key;
> > + u32 b;
> > +
> > + if (key_len == sizeof(u32))
> > + b = 0;
> > + else if (key_len == sizeof(u64))
> > + b = k[1];
> > + else if (likely(key_len % 4 == 0))
> > return jhash2(key, key_len / 4, hashrnd);
Nice improvement, but key_size is known at verification time.
Let's do a step further and specialize htab_map_gen_lookup
for small key sizes?
next prev parent reply other threads:[~2026-09-21 17:00 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-09-21 15:28 [PATCH bpf-next] bpf: Speed up htab hashing for u32/u64 keys Mykyta Yatsenko
2026-09-21 16:45 ` Anton Protopopov
[not found] ` <179000542526.3934731.994864591824564797@gmail.com>
2026-09-21 17:00 ` Alexei Starovoitov [this message]
2026-09-21 17:10 ` Mykyta Yatsenko
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