Thread (1 message) flat view 1 message, 1 author, 2024-02-20
STALE861d REVIEWED: 4 (4M)

Revision v2 of 2 in this series; 2 review trailers.

Revisions (2)
  1. v1 [diff vs current]
  2. v2 current

[PATCH net-next v2 3/4] bpf: test_run: Fix cacheline alignment of live XDP frame data structures

From: Toke Høiland-Jørgensen <hidden>
Date: 2024-02-20 21:03:52
Also in: bpf
Subsystem: bpf [general] (safe dynamic programs and tools), networking [general], the rest · Maintainers: Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds

The live XDP frame code in BPF_PROG_RUN suffered from suboptimal cache
line placement due to the forced cache line alignment of struct
xdp_rxq_info. Rearrange things so we don't waste a whole cache line on
padding, and also add explicit alignment to the data_hard_start field in
the start-of-page data structure we use for the data pages.

Reviewed-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Tested-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Signed-off-by: Toke Høiland-Jørgensen <redacted>
---
 net/bpf/test_run.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/net/bpf/test_run.c b/net/bpf/test_run.c
index 60a36a4df3e1..485084c302b2 100644
--- a/net/bpf/test_run.c
+++ b/net/bpf/test_run.c
@@ -113,12 +113,12 @@ struct xdp_page_head {
 		/* ::data_hard_start starts here */
 		DECLARE_FLEX_ARRAY(struct xdp_frame, frame);
 		DECLARE_FLEX_ARRAY(u8, data);
-	};
+	} ____cacheline_aligned;
 };
 
 struct xdp_test_data {
-	struct xdp_buff *orig_ctx;
 	struct xdp_rxq_info rxq;
+	struct xdp_buff *orig_ctx;
 	struct net_device *dev;
 	struct xdp_frame **frames;
 	struct sk_buff **skbs;
-- 
2.43.0
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help