lkml.org 
[lkml]   [2017]   [Jul]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 2/6] dma: bcm-sba-raid: Peek mbox when we are left with no free requests
On Thu, Jul 27, 2017 at 10:25:25AM +0530, Anup Patel wrote:
> On Wed, Jul 26, 2017 at 10:40 PM, Vinod Koul <vinod.koul@intel.com> wrote:
> > On Wed, Jul 26, 2017 at 11:06:40AM +0530, Anup Patel wrote:
> >> We should peek mbox channels when we are left with no free
> >> sba_requests in sba_alloc_request()
> >
> > and why is the world should we do that, how does that help??
>
> When setting up RAID array on several NVMe disk we observed
> that sba_alloc_request() start failing (due to no free requests left)
> and RAID array setup becomes very slow.
>
> Doing mbox channel peek when we have no free requests left,
> improves performance of RAID array setup.

How about documenting this tribal knowledge in the changelog. Changelogs are
very useful, 6 months down the line, you will struggle to remember why this
was changed..

>
> This change is inspired from mv_chan_alloc_slot() implemented
> in drivers/dma/mv_xor.c
>
> Regards,
> Anup

--
~Vinod

\
 
 \ /
  Last update: 2017-07-28 05:12    [W:0.059 / U:9.180 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site