RE: [patch] Performance enhancement patches for SB1250 MAC

The patches have been tested on non-SMP and SMP configurations.

Regards, 
Steve Yang

-----Original Message-----
From: Stephen Hemminger [mailto:shemminger@osdl.org] 
Sent: Tuesday, November 21, 2006 11:13 AM
To: Yang, Steve
Cc: Martin Michlmayr; netdev@vger.kernel.org
Subject: Re: [patch] Performance enhancement patches for SB1250 MAC

On Tue, 21 Nov 2006 08:45:58 -0800
"Yang, Steve" [off-list ref] wrote:

Martin,

I've attached the two patches with this email.

Original submission email text:

"The attached are two network performance enhancement patches for 
SB1250 MAC. The NAPI patch applies first. Followed by the "skb cache"

patch.

They applied and builds cleanly on 2.6.18 kernel for the following 
kernel option combinations:

SBMAC_NAPI	no	yes	yes
SKB_CACHE	no	no	yes"

Regards,
Steve Yang

-----Original Message-----
From: Martin Michlmayr [mailto:tbm@cyrius.com]
Sent: Tuesday, November 21, 2006 6:27 AM
To: Stephen Hemminger
Cc: Yang, Steve; netdev@vger.kernel.org
Subject: Re: [patch] Performance enhancement patches for SB1250 MAC

* Stephen Hemminger [off-list ref] [2006-11-20 15:35]:

quoted

quoted

1. I've submitted two patches, one for NAPI and the other for

SKB_Cache.

quoted

quoted

They can go in individually. You've expressed objections to

SKB_Cache.

quoted

quoted

What about the one for NAPI?

Yes, the NAPI one is great.

Should Steve resend the patch so it can be added or is it queued up 
already?  It would be nice to have this in 2.6.20.
--
Martin Michlmayr
tbm@cyrius.com

One comment about the driver in general (not NAPI related), is that
almost all uses of "volatile" in a driver are incorrect.  Especially
these because the device memory (__iomem) should already be mapped
non-cached.

Volatile protects against compiler issues, not device consistency.

@@ -197,13 +206,16 @@
 	volatile void __iomem *sbdma_config0;	/* DMA config register 0

*/
 	volatile void __iomem *sbdma_config1;	/* DMA config register 1
*/
 	volatile void __iomem *sbdma_dscrbase;	/* Descriptor base
address */
-	volatile void __iomem *sbdma_dscrcnt;     /* Descriptor count
register */
+	volatile void __iomem *sbdma_dscrcnt;   /* Descriptor count
register */
 	volatile void __iomem *sbdma_curdscr;	/* current descriptor
address */
+	volatile void __iomem *sbdma_oodpktlost;/* pkt drop (rx only) */
+
 
Also, how is this NAPI related (probably should be a different patch.
But I no nothing about MIPS SMP.

Index: linux-2.6.14-cgl/arch/mips/sibyte/bcm1480/irq.c
===================================================================

--- linux-2.6.14-cgl.orig/arch/mips/sibyte/bcm1480/irq.c

2006-09-20 14:58:41.000000000 -0700

+++ linux-2.6.14-cgl/arch/mips/sibyte/bcm1480/irq.c	2006-09-20

15:58:33.000000000 -0700

@@ -144,11 +144,11 @@
 	unsigned long flags;
 	unsigned int irq_dirty;
 
-	i = first_cpu(mask);
-	if (next_cpu(i, mask) <= NR_CPUS) {
+	if (cpus_weight(mask) != 1) {
 		printk("attempted to set irq affinity for irq %d to

multiple CPUs\n", irq);
 		return;
 	}
+	i = first_cpu(mask);
 
 	/* Convert logical CPU to physical CPU */
 	cpu = cpu_logical_map(i);



--
Stephen Hemminger [off-list ref]