Re: [PATCH v2 1/2] hpsa: limit transfer length to 1MB

2017-07-17 Thread Martin K. Petersen 

Yadan,

> The hpsa firmware will bypass the cache for any request larger
> than 1MB, so we should cap the request size to avoid any
> performance degradation in kernels later than v4.3

Applied to 4.13/scsi-fixes. Thanks!

-- 
Martin K. Petersen  Oracle Linux Engineering

Re: [PATCH v2 1/2] hpsa: limit transfer length to 1MB

2017-06-26 Thread Martin K. Petersen 

Don,

> The hpsa firmware will bypass the cache for any request larger than
> 1MB, so we should cap the request size to avoid any performance
> degradation in kernels later than v4.3

I assume you guys are OK with this change?

-- 
Martin K. Petersen  Oracle Linux Engineering

Re: [PATCH v2 1/2] hpsa: limit transfer length to 1MB

2017-06-23 Thread Johannes Thumshirn 
On Fri, Jun 23, 2017 at 05:40:05PM +0800, Yadan Fan wrote:
> The hpsa firmware will bypass the cache for any request larger
> than 1MB, so we should cap the request size to avoid any
> performance degradation in kernels later than v4.3
> 
> This degradation is caused from d2be537c3ba3568acd79cd178327b842e60d035e,
> which changed max_sectors_kb to 1280k, but the hardware is able to
> work fine with it, so the true fix should be from hpsa driver.
> 
> Signed-off-by: Yadan Fan 
> ---

Reviewed-by: Johannes Thumshirn 
-- 
Johannes Thumshirn  Storage
jthumsh...@suse.de+49 911 74053 689
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
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[PATCH v2 1/2] hpsa: limit transfer length to 1MB

2017-06-23 Thread Yadan Fan 
The hpsa firmware will bypass the cache for any request larger
than 1MB, so we should cap the request size to avoid any
performance degradation in kernels later than v4.3

This degradation is caused from d2be537c3ba3568acd79cd178327b842e60d035e,
which changed max_sectors_kb to 1280k, but the hardware is able to
work fine with it, so the true fix should be from hpsa driver.

Signed-off-by: Yadan Fan 
---

Changes: 
 Reduced SUSE distribution info and internal bug id reference.

 drivers/scsi/hpsa.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/scsi/hpsa.c b/drivers/scsi/hpsa.c
index 73daace478cb..b4c0bbea680c 100644
--- a/drivers/scsi/hpsa.c
+++ b/drivers/scsi/hpsa.c
@@ -952,7 +952,7 @@ static struct scsi_host_template hpsa_driver_template = {
 #endif
.sdev_attrs = hpsa_sdev_attrs,
.shost_attrs = hpsa_shost_attrs,
-   .max_sectors = 8192,
+   .max_sectors = 1024,
.no_write_same = 1,
 };
 
-- 
2.12.3