diff mbox series

[v4,bpf-next] cpumap: bulk skb using netif_receive_skb_list

Message ID c729f83e5d7482d9329e0f165bdbe5adcefd1510.1619169700.git.lorenzo@kernel.org (mailing list archive)
State Accepted
Commit bb0247807744dc93407771e13ba20af0b270ca6a
Delegated to: BPF
Headers show
Series [v4,bpf-next] cpumap: bulk skb using netif_receive_skb_list | expand

Checks

Context Check Description
netdev/cover_letter success Link
netdev/fixes_present success Link
netdev/patch_count success Link
netdev/tree_selection success Clearly marked for bpf-next
netdev/subject_prefix success Link
netdev/cc_maintainers warning 7 maintainers not CCed: yhs@fb.com kpsingh@kernel.org hawk@kernel.org andrii@kernel.org kafai@fb.com john.fastabend@gmail.com songliubraving@fb.com
netdev/source_inline success Was 0 now: 0
netdev/verify_signedoff success Link
netdev/module_param success Was 0 now: 0
netdev/build_32bit success Errors and warnings before: 1 this patch: 1
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/verify_fixes success Link
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 54 lines checked
netdev/build_allmodconfig_warn success Errors and warnings before: 1 this patch: 1
netdev/header_inline success Link

Commit Message

lorenzo@kernel.org April 23, 2021, 9:27 a.m. UTC
Rely on netif_receive_skb_list routine to send skbs converted from
xdp_frames in cpu_map_kthread_run in order to improve i-cache usage.
The proposed patch has been tested running xdp_redirect_cpu bpf sample
available in the kernel tree that is used to redirect UDP frames from
ixgbe driver to a cpumap entry and then to the networking stack.
UDP frames are generated using pkt_gen. Packets are discarded by the
UDP layer.

$xdp_redirect_cpu  --cpu <cpu> --progname xdp_cpu_map0 --dev <eth>

bpf-next: ~2.35Mpps
bpf-next + cpumap skb-list: ~2.72Mpps

Rename drops counter in kmem_alloc_drops since now it reports just
kmem_cache_alloc_bulk failures

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
---
Changes since v3:
- drop tracepoint layout/xdp samples changes and rename drops
  variable in kmem_alloc_drops

Changes since v2:
- remove drop counter and update related xdp samples
- rebased on top of bpf-next

Changes since v1:
- fixed comment
- rebased on top of bpf-next tree
---
 kernel/bpf/cpumap.c | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

Comments

Jesper Dangaard Brouer April 23, 2021, 10:34 a.m. UTC | #1
On Fri, 23 Apr 2021 11:27:27 +0200
Lorenzo Bianconi <lorenzo@kernel.org> wrote:

> Rely on netif_receive_skb_list routine to send skbs converted from
> xdp_frames in cpu_map_kthread_run in order to improve i-cache usage.
> The proposed patch has been tested running xdp_redirect_cpu bpf sample
> available in the kernel tree that is used to redirect UDP frames from
> ixgbe driver to a cpumap entry and then to the networking stack.
> UDP frames are generated using pkt_gen. Packets are discarded by the
> UDP layer.
> 
> $xdp_redirect_cpu  --cpu <cpu> --progname xdp_cpu_map0 --dev <eth>
> 
> bpf-next: ~2.35Mpps
> bpf-next + cpumap skb-list: ~2.72Mpps
> 
> Rename drops counter in kmem_alloc_drops since now it reports just
> kmem_cache_alloc_bulk failures
> 
> Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>

Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
patchwork-bot+netdevbpf@kernel.org April 27, 2021, 3:20 p.m. UTC | #2
Hello:

This patch was applied to bpf/bpf-next.git (refs/heads/master):

On Fri, 23 Apr 2021 11:27:27 +0200 you wrote:
> Rely on netif_receive_skb_list routine to send skbs converted from
> xdp_frames in cpu_map_kthread_run in order to improve i-cache usage.
> The proposed patch has been tested running xdp_redirect_cpu bpf sample
> available in the kernel tree that is used to redirect UDP frames from
> ixgbe driver to a cpumap entry and then to the networking stack.
> UDP frames are generated using pkt_gen. Packets are discarded by the
> UDP layer.
> 
> [...]

Here is the summary with links:
  - [v4,bpf-next] cpumap: bulk skb using netif_receive_skb_list
    https://git.kernel.org/bpf/bpf-next/c/bb0247807744

You are awesome, thank you!
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diff mbox series

Patch

diff --git a/kernel/bpf/cpumap.c b/kernel/bpf/cpumap.c
index 0cf2791d5099..5dd3e866599a 100644
--- a/kernel/bpf/cpumap.c
+++ b/kernel/bpf/cpumap.c
@@ -27,7 +27,7 @@ 
 #include <linux/capability.h>
 #include <trace/events/xdp.h>
 
-#include <linux/netdevice.h>   /* netif_receive_skb_core */
+#include <linux/netdevice.h>   /* netif_receive_skb_list */
 #include <linux/etherdevice.h> /* eth_type_trans */
 
 /* General idea: XDP packets getting XDP redirected to another CPU,
@@ -252,11 +252,12 @@  static int cpu_map_kthread_run(void *data)
 	 */
 	while (!kthread_should_stop() || !__ptr_ring_empty(rcpu->queue)) {
 		struct xdp_cpumap_stats stats = {}; /* zero stats */
+		unsigned int kmem_alloc_drops = 0, sched = 0;
 		gfp_t gfp = __GFP_ZERO | GFP_ATOMIC;
-		unsigned int drops = 0, sched = 0;
 		void *frames[CPUMAP_BATCH];
 		void *skbs[CPUMAP_BATCH];
 		int i, n, m, nframes;
+		LIST_HEAD(list);
 
 		/* Release CPU reschedule checks */
 		if (__ptr_ring_empty(rcpu->queue)) {
@@ -297,7 +298,7 @@  static int cpu_map_kthread_run(void *data)
 			if (unlikely(m == 0)) {
 				for (i = 0; i < nframes; i++)
 					skbs[i] = NULL; /* effect: xdp_return_frame */
-				drops += nframes;
+				kmem_alloc_drops += nframes;
 			}
 		}
 
@@ -305,7 +306,6 @@  static int cpu_map_kthread_run(void *data)
 		for (i = 0; i < nframes; i++) {
 			struct xdp_frame *xdpf = frames[i];
 			struct sk_buff *skb = skbs[i];
-			int ret;
 
 			skb = __xdp_build_skb_from_frame(xdpf, skb,
 							 xdpf->dev_rx);
@@ -314,13 +314,13 @@  static int cpu_map_kthread_run(void *data)
 				continue;
 			}
 
-			/* Inject into network stack */
-			ret = netif_receive_skb_core(skb);
-			if (ret == NET_RX_DROP)
-				drops++;
+			list_add_tail(&skb->list, &list);
 		}
+		netif_receive_skb_list(&list);
+
 		/* Feedback loop via tracepoint */
-		trace_xdp_cpumap_kthread(rcpu->map_id, n, drops, sched, &stats);
+		trace_xdp_cpumap_kthread(rcpu->map_id, n, kmem_alloc_drops,
+					 sched, &stats);
 
 		local_bh_enable(); /* resched point, may call do_softirq() */
 	}