From: Jesper Dangaard Brouer <brouer@redhat.com>
To: John Fastabend <john.fastabend@gmail.com>
Cc: netdev@vger.kernel.org, davem@davemloft.net, andy@greyhouse.net,
daniel@iogearbox.net, ast@fb.com, brouer@redhat.com
Subject: Re: [RFC PATCH 10/12] xdp: Add batching support to redirect map
Date: Mon, 10 Jul 2017 19:53:55 +0200 [thread overview]
Message-ID: <20170710195355.40fd9caa@redhat.com> (raw)
In-Reply-To: <20170707173759.9984.5709.stgit@john-Precision-Tower-5810>
On Fri, 07 Jul 2017 10:37:59 -0700
John Fastabend <john.fastabend@gmail.com> wrote:
> diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c
> index 36dc13de..656e334 100644
> --- a/kernel/bpf/devmap.c
> +++ b/kernel/bpf/devmap.c
[...]
>
> +void __dev_map_insert_ctx(struct bpf_map *map, u32 key)
> +{
> + struct bpf_dtab *dtab = container_of(map, struct bpf_dtab, map);
> + unsigned long *bitmap = this_cpu_ptr(dtab->flush_needed);
> +
> + set_bit(key, bitmap);
> +}
I don't like that this adds an atomic op (set_bit) per packet on a fast-path.
It shows up on a perf top #6 with xdp_redirect_map.
--
Best regards,
Jesper Dangaard Brouer
MSc.CS, Principal Kernel Engineer at Red Hat
LinkedIn: http://www.linkedin.com/in/brouer
next prev parent reply other threads:[~2017-07-10 17:54 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-07-07 17:34 [RFC PATCH 00/12] Implement XDP bpf_redirect vairants John Fastabend
2017-07-07 17:34 ` [RFC PATCH 01/12] ixgbe: NULL xdp_tx rings on resource cleanup John Fastabend
2017-07-07 17:35 ` [RFC PATCH 02/12] net: xdp: support xdp generic on virtual devices John Fastabend
2017-07-07 17:35 ` [RFC PATCH 03/12] xdp: add bpf_redirect helper function John Fastabend
2017-07-09 13:37 ` Saeed Mahameed
2017-07-10 17:23 ` John Fastabend
2017-07-11 14:09 ` Andy Gospodarek
2017-07-11 18:38 ` John Fastabend
2017-07-11 19:38 ` Jesper Dangaard Brouer
2017-07-12 11:00 ` Saeed Mahameed
2017-07-07 17:35 ` [RFC PATCH 04/12] xdp: sample program for new bpf_redirect helper John Fastabend
2017-07-07 17:36 ` [RFC PATCH 05/12] net: implement XDP_REDIRECT for xdp generic John Fastabend
2017-07-07 17:36 ` [RFC PATCH 06/12] ixgbe: add initial support for xdp redirect John Fastabend
2017-07-07 17:36 ` [RFC PATCH 07/12] xdp: add trace event " John Fastabend
2017-07-07 17:37 ` [RFC PATCH 08/12] bpf: add devmap, a map for storing net device references John Fastabend
2017-07-08 18:57 ` Jesper Dangaard Brouer
2017-07-07 17:37 ` [RFC PATCH 09/12] bpf: add bpf_redirect_map helper routine John Fastabend
2017-07-07 17:37 ` [RFC PATCH 10/12] xdp: Add batching support to redirect map John Fastabend
2017-07-10 17:53 ` Jesper Dangaard Brouer [this message]
2017-07-10 17:56 ` John Fastabend
2017-07-07 17:38 ` [RFC PATCH 11/12] net: add notifier hooks for devmap bpf map John Fastabend
2017-07-07 17:38 ` [RFC PATCH 12/12] xdp: bpf redirect with map sample program John Fastabend
2017-07-07 17:48 ` [RFC PATCH 00/12] Implement XDP bpf_redirect vairants John Fastabend
2017-07-08 9:46 ` David Miller
2017-07-08 19:06 ` Jesper Dangaard Brouer
2017-07-10 18:30 ` Jesper Dangaard Brouer
2017-07-11 0:59 ` John Fastabend
2017-07-11 14:23 ` Jesper Dangaard Brouer
2017-07-11 18:26 ` John Fastabend
2017-07-13 11:14 ` Jesper Dangaard Brouer
2017-07-13 16:16 ` Jesper Dangaard Brouer
2017-07-13 17:00 ` John Fastabend
2017-07-13 18:21 ` David Miller
2017-07-11 15:36 ` Jesper Dangaard Brouer
2017-07-11 17:48 ` John Fastabend
2017-07-11 18:01 ` Jesper Dangaard Brouer
2017-07-11 18:29 ` John Fastabend
2017-07-11 18:44 ` Jesper Dangaard Brouer
2017-07-11 18:56 ` John Fastabend
2017-07-11 19:19 ` Jesper Dangaard Brouer
2017-07-11 19:37 ` John Fastabend
2017-07-16 8:23 ` Jesper Dangaard Brouer
2017-07-17 17:04 ` Jesse Brandeburg
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