Re: [PATCH v2 3/3] bpf: hash: use per-bucket spinlock

From	Daniel Borkmann <daniel@iogearbox.net>
Newsgroups	linux.kernel
Subject	Re: [PATCH v2 3/3] bpf: hash: use per-bucket spinlock
Date	2015-12-29 17:30 +0100
Message-ID	<qL5jQ-2Vk-5@gated-at.bofh.it> (permalink)
References	<qL3L3-1P0-1@gated-at.bofh.it> <qL3UK-1Sp-7@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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On 12/29/2015 03:40 PM, Ming Lei wrote:
> Both htab_map_update_elem() and htab_map_delete_elem() can be
> called from eBPF program, and they may be in kernel hot path,
> so it isn't efficient to use a per-hashtable lock in this two
> helpers.
>
> The per-hashtable spinlock is used for protecting bucket's
> hlist, and per-bucket lock is just enough. This patch converts
> the per-hashtable lock into per-bucket spinlock, so that
> contention can be decreased a lot.
>
> Signed-off-by: Ming Lei <tom.leiming@gmail.com>

Looks better, thanks!

Acked-by: Daniel Borkmann <daniel@iogearbox.net>
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Thread

[PATCH v2 0/3] bpf: hash: use per-bucket spinlock  Ming Lei <tom.leiming@gmail.com> - 2015-12-29 15:50 +0100
  [PATCH v2 1/3] bpf: hash: use atomic count Ming Lei <tom.leiming@gmail.com> - 2015-12-29 15:50 +0100
  [PATCH v2 2/3] bpf: hash: move select_bucket() out of htab's spinlock Ming Lei <tom.leiming@gmail.com> - 2015-12-29 15:50 +0100
  [PATCH v2 3/3] bpf: hash: use per-bucket spinlock Ming Lei <tom.leiming@gmail.com> - 2015-12-29 16:00 +0100
    Re: [PATCH v2 3/3] bpf: hash: use per-bucket spinlock Daniel Borkmann <daniel@iogearbox.net> - 2015-12-29 17:30 +0100
  Re: [PATCH v2 0/3] bpf: hash: use per-bucket spinlock  David Miller <davem@davemloft.net> - 2015-12-29 21:20 +0100

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