RE: [PATCH][SDK v1.2] sata: I/O load balancing

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From: linux-ide-owner@vger.kernel.org [linux-ide-owner@vger.kernel.org] o=

n behalf of Li Yang [leoli@freescale.com]=0A=

Sent: Friday, January 13, 2012 3:36 AM=0A=
To: Liu Qiang-B32616=0A=
Cc: jgarzik@pobox.com; linux-ide@vger.kernel.org; linux-kernel@vger.kerne=

l.org; linuxppc-dev@lists.ozlabs.org; Liu Qiang-B32616=0A=

Subject: Re: [PATCH][SDK v1.2] sata: I/O load balancing=0A=

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On Fri, Jan 13, 2012 at 4:25 PM, Qiang Liu [off-list ref] wrot=

e:=0A=

quoted

From: Qiang Liu <redacted>=0A=
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Reduce interrupt singnals through reset Interrupt Coalescing Control Re=

g.=0A=

quoted

Increase the threshold value of interrupt and timer will reduce the num=

ber=0A=

quoted

of complete interrupt sharply. Improve the system performance effective=

ly.=0A=
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There is always a trade off of throughput and latency by using=0A=
interrupt coalescing.  It's not reasonable to assume that the=0A=
throughput is the only factor to be considered and set the coalescing=0A=
threshold and timeout to the max value by default.  Have you carried=0A=
out other benchmark like copying many small files?=0A=

No, I didn't test small file. I think this won't affect system load. I can =
have a test=0A=
and describe the result in next patch.=0A=
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It will be safer to make the coalescing runtime configurable like the=0A=
sata_mv driver, IMO.=0A=

Ok, I will do it like this in next patch.=0A=
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