Thread (5 messages) flat view 5 messages, 2 authors, 2012-12-17

[PATCH 3/3 v2] net/macb: Try to optimize struct macb layout

From: Ben Hutchings <hidden>
Date: 2012-12-17 13:52:33
Also in: lkml, netdev

On Mon, 2012-12-17 at 14:01 +0100, Nicolas Ferre wrote:
From: Havard Skinnemoen <redacted>

Move TX-related fields to the top of the struct so that they end up on
the same cache line. Move the NAPI struct below that since it is used
from the interrupt handler. RX-related fields go below those.
quoted hunk ↗ jump to hunk
Move the spinlock before regs since they are usually used together.

Signed-off-by: Havard Skinnemoen <redacted>
[nicolas.ferre at atmel.com: adapt to newer kernel]
Signed-off-by: Nicolas Ferre <redacted>
---
 drivers/net/ethernet/cadence/macb.h | 25 +++++++++++++------------
 1 file changed, 13 insertions(+), 12 deletions(-)
diff --git a/drivers/net/ethernet/cadence/macb.h b/drivers/net/ethernet/cadence/macb.h
index cef146f..aeeb729 100644
--- a/drivers/net/ethernet/cadence/macb.h
+++ b/drivers/net/ethernet/cadence/macb.h
@@ -548,38 +548,39 @@ struct macb_or_gem_ops {
 };
 
 struct macb {
+	spinlock_t		lock;
 	void __iomem		*regs;
 
+	unsigned int		tx_head;
+	unsigned int		tx_tail;
+	struct macb_dma_desc	*tx_ring;
+	struct macb_tx_skb	*tx_skb;
+	dma_addr_t		tx_ring_dma;
+	struct work_struct	tx_error_task;
+
+	struct napi_struct	napi;
[...]

If this driver may be used on SMP systems them 'napi' should be declared
with the suffix ___cacheline_aligned_in_smp.

Ben.

-- 
Ben Hutchings, Staff Engineer, Solarflare
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.
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