On Tue, Apr 14, 2009 at 07:57:57AM -0400, Jeff Garzik wrote:
> Alexander Beregalov wrote:
> > ECC initialization takes too long. It writes zeroes by portions of 4
> > byte, it takes more than 6 minutes to initialize 512Mb DIMM module.
> > Change portion to 1Mb.
> >
> > before:
> > [10857.207576] pdc20621_dimm_init: Start ECC initialization
> > [11235.333118] pdc20621_dimm_init: Finish ECC initialization
> >
> > after:
> > [ 1005.126437] pdc20621_dimm_init: Local DIMM Speed = 100
> > [ 1005.128111] pdc20621_dimm_init: Local DIMM Size = 512MB
> > [ 1005.133508] Local DIMM ECC Enabled
> > [ 1005.236482] pdc20621_dimm_init: Start ECC initialization
> > [ 1031.278098] pdc20621_dimm_init: Finish ECC initialization
> >
> Comments:
>
> 1) on an older machine, where these things might be found, 1MB might be
> a lot -- particularly if there is a lot of VM fragmentation. Please
> reduce the size a bit -- I suppose 128k is not unbearably slow?
>
> 2) Rather than repeating 'page size * 32' calculation multiple times,
> put it into a named constant somewhere.
>
> Other than that, looks ok!
>From 00e980a4651ef12811fbe9a893a7e72510b955d1 Mon Sep 17 00:00:00 2001
From: Alexander Beregalov <a.beregalov@xxxxxxxxx>
Date: Tue, 14 Apr 2009 23:55:52 +0400
Subject: [PATCH v2] sata_sx4: speed up ECC initialization
ECC initialization takes too long. It writes zeroes by portions
of 4 byte, it takes more than 6 minutes on my machine to initialize
512Mb ECC DIMM module. Change portion to 128Kb - it significantly
reduces initialization time.
Signed-off-by: Alexander Beregalov <a.beregalov@xxxxxxxxx>
---
drivers/ata/sata_sx4.c | 11 +++++++----
1 files changed, 7 insertions(+), 4 deletions(-)
diff --git a/drivers/ata/sata_sx4.c b/drivers/ata/sata_sx4.c
index dce3dcc..197a4d7 100644
--- a/drivers/ata/sata_sx4.c
+++ b/drivers/ata/sata_sx4.c
@@ -193,6 +193,7 @@ enum {
PDC_TIMER_MASK_INT,
};
+#define ECC_ERASE_BUF 128 * 1024;
struct pdc_port_priv {
u8 dimm_buf[(ATA_PRD_SZ * ATA_MAX_PRD) + 512];
@@ -1208,7 +1209,6 @@ static unsigned int pdc20621_dimm_init(struct ata_host *host)
{
int speed, size, length;
u32 addr, spd0, pci_status;
- u32 tmp = 0;
u32 time_period = 0;
u32 tcount = 0;
u32 ticks = 0;
@@ -1323,14 +1323,17 @@ static unsigned int pdc20621_dimm_init(struct ata_host *host)
pdc20621_i2c_read(host, PDC_DIMM0_SPD_DEV_ADDRESS,
PDC_DIMM_SPD_TYPE, &spd0);
if (spd0 == 0x02) {
+ void *buf;
VPRINTK("Start ECC initialization\n");
addr = 0;
length = size * 1024 * 1024;
+ buf = kzalloc(ECC_ERASE_BUF, GFP_KERNEL);
while (addr < length) {
- pdc20621_put_to_dimm(host, (void *) &tmp, addr,
- sizeof(u32));
- addr += sizeof(u32);
+ pdc20621_put_to_dimm(host, buf, addr,
+ ECC_ERASE_BUF);
+ addr += ECC_ERASE_BUF;
}
+ kfree(buf);
VPRINTK("Finish ECC initialization\n");
}
return 0;
--
1.6.2.3
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