From: Jesper Dangaard Brouer <brouer@redhat.com>
To: Lorenzo Bianconi <lorenzo@kernel.org>
Cc: bpf@vger.kernel.org, netdev@vger.kernel.org, davem@davemloft.net,
ast@kernel.org, daniel@iogearbox.net, toke@redhat.com,
lorenzo.bianconi@redhat.com, dsahern@kernel.org,
brouer@redhat.com
Subject: Re: [PATCH v2 bpf-next 4/8] bpf: cpumap: add the possibility to attach an eBPF program to cpumap
Date: Tue, 23 Jun 2020 16:56:12 +0200 [thread overview]
Message-ID: <20200623165612.2596954b@carbon> (raw)
In-Reply-To: <734113565894cb8447d1526e6a93eaf6ae994c2d.1592606391.git.lorenzo@kernel.org>
On Sat, 20 Jun 2020 00:57:20 +0200
Lorenzo Bianconi <lorenzo@kernel.org> wrote:
> @@ -273,16 +336,20 @@ static int cpu_map_kthread_run(void *data)
> prefetchw(page);
> }
>
> - m = kmem_cache_alloc_bulk(skbuff_head_cache, gfp, n, skbs);
> + /* Support running another XDP prog on this CPU */
> + nframes = cpu_map_bpf_prog_run_xdp(rcpu, xdp_frames, n, &stats);
> +
If all frames are dropped my XDP program, then we will call
kmem_cache_alloc_bulk() to allocate zero elements. I found this during
my testing[1], and I think we should squash my proposed change in[1].
> + m = kmem_cache_alloc_bulk(skbuff_head_cache, gfp,
> + nframes, skbs);
> if (unlikely(m == 0)) {
> - for (i = 0; i < n; i++)
> + for (i = 0; i < nframes; i++)
> skbs[i] = NULL; /* effect: xdp_return_frame */
> - drops = n;
> + drops += nframes;
> }
>
> local_bh_disable();
> - for (i = 0; i < n; i++) {
> - struct xdp_frame *xdpf = frames[i];
> + for (i = 0; i < nframes; i++) {
> + struct xdp_frame *xdpf = xdp_frames[i];
> struct sk_buff *skb = skbs[i];
> int ret;
[1] https://github.com/xdp-project/xdp-project/blob/master/areas/cpumap/cpumap04-map-xdp-prog.org#observations
--
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:[~2020-06-23 14:56 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-19 22:57 [PATCH v2 bpf-next 0/8] introduce support for XDP programs in CPUMAP Lorenzo Bianconi
2020-06-19 22:57 ` [PATCH v2 bpf-next 1/8] net: Refactor xdp_convert_buff_to_frame Lorenzo Bianconi
2020-06-21 15:15 ` Jesper Dangaard Brouer
2020-06-22 11:48 ` Lorenzo Bianconi
2020-06-19 22:57 ` [PATCH v2 bpf-next 2/8] samples/bpf: xdp_redirect_cpu_user: do not update bpf maps in option loop Lorenzo Bianconi
2020-06-21 15:26 ` Jesper Dangaard Brouer
2020-06-19 22:57 ` [PATCH v2 bpf-next 3/8] cpumap: formalize map value as a named struct Lorenzo Bianconi
2020-06-22 9:33 ` Jesper Dangaard Brouer
2020-06-22 11:50 ` Lorenzo Bianconi
2020-06-19 22:57 ` [PATCH v2 bpf-next 4/8] bpf: cpumap: add the possibility to attach an eBPF program to cpumap Lorenzo Bianconi
2020-06-22 9:48 ` Jesper Dangaard Brouer
2020-06-23 14:56 ` Jesper Dangaard Brouer [this message]
2020-06-23 15:23 ` Jesper Dangaard Brouer
2020-06-19 22:57 ` [PATCH v2 bpf-next 5/8] bpf: cpumap: implement XDP_REDIRECT for eBPF programs attached to map entries Lorenzo Bianconi
2020-06-19 22:57 ` [PATCH v2 bpf-next 6/8] libbpf: add SEC name for xdp programs attached to CPUMAP Lorenzo Bianconi
2020-06-23 5:50 ` Andrii Nakryiko
2020-06-19 22:57 ` [PATCH v2 bpf-next 7/8] samples/bpf: xdp_redirect_cpu: load a eBPF program on cpumap Lorenzo Bianconi
2020-06-19 22:57 ` [PATCH v2 bpf-next 8/8] selftest: add tests for XDP programs in CPUMAP entries Lorenzo Bianconi
2020-06-23 5:55 ` Andrii Nakryiko
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