netdev - Re: [PATCH bpf] bpf: enforce BPF ringbuf size to be the power of 2

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Message-ID: <0afa8e51-594f-275d-c9df-112606742523@fb.com>
Date:   Mon, 29 Jun 2020 20:08:38 -0700
From:   Yonghong Song <yhs@...com>
To:     Andrii Nakryiko <andriin@...com>, <bpf@...r.kernel.org>,
        <netdev@...r.kernel.org>, <ast@...com>, <daniel@...earbox.net>
CC:     <andrii.nakryiko@...il.com>, <kernel-team@...com>
Subject: Re: [PATCH bpf] bpf: enforce BPF ringbuf size to be the power of 2



On 6/29/20 3:17 PM, Andrii Nakryiko wrote:
> BPF ringbuf assumes the size to be a multiple of page size and the power of
> 2 value. The latter is important to avoid division while calculating position
> inside the ring buffer and using (N-1) mask instead. This patch fixes omission
> to enforce power-of-2 size rule.
> 
> Fixes: 457f44363a88 ("bpf: Implement BPF ring buffer and verifier support for it")
> Signed-off-by: Andrii Nakryiko <andriin@...com>

Acked-by: Yonghong Song <yhs@...com>