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Date:   Thu, 27 Jun 2019 15:14:36 -0700
From:   Alexei Starovoitov <alexei.starovoitov@gmail.com>
To:     Brian Vazquez <brianvv@google.com>
Cc:     Brian Vazquez <brianvv.kernel@gmail.com>,
        Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        "David S . Miller" <davem@davemloft.net>,
        Stanislav Fomichev <sdf@google.com>,
        Willem de Bruijn <willemb@google.com>,
        Petar Penkov <ppenkov@google.com>,
        linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
        bpf@vger.kernel.org
Subject: Re: [RFC PATCH bpf-next v2 0/6]  bpf: add BPF_MAP_DUMP command to
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On Thu, Jun 27, 2019 at 01:24:11PM -0700, Brian Vazquez wrote:
> This introduces a new command to retrieve a variable number of entries
> from a bpf map.
> 
> This new command can be executed from the existing BPF syscall as
> follows:
> 
> err =  bpf(BPF_MAP_DUMP, union bpf_attr *attr, u32 size)
> using attr->dump.map_fd, attr->dump.prev_key, attr->dump.buf,
> attr->dump.buf_len
> returns zero or negative error, and populates buf and buf_len on
> succees
> 
> This implementation is wrapping the existing bpf methods:
> map_get_next_key and map_lookup_elem
> the results show that even with a 1-elem_size buffer, it runs ~40 faster
> than the current implementation, improvements of ~85% are reported when
> the buffer size is increased, although, after the buffer size is around
> 5% of the total number of entries there's no huge difference in
> increasing
> it.

was it with kpti and retpoline mitigations?