Re: [PATCH 2/6] dma: bcm-sba-raid: Peek mbox when we are left with no free requests

From	Anup Patel <anup.patel@broadcom.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH 2/6] dma: bcm-sba-raid: Peek mbox when we are left with no free requests
Date	2017-07-28 05:40 +0200
Message-ID	<u84i5-6MU-3@gated-at.bofh.it> (permalink)
References	<u7nd7-4CC-5@gated-at.bofh.it> <u7nd8-4CC-21@gated-at.bofh.it> <u7xYS-37A-3@gated-at.bofh.it> <u7J3X-1zN-7@gated-at.bofh.it> <u83YJ-6Cu-1@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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On Fri, Jul 28, 2017 at 8:45 AM, Vinod Koul <vinod.koul@intel.com> wrote:
> 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..

Sure, I will have detailed commit description for this.

Regards,
Anup

Thread

[PATCH 0/6] Broadcom SBA-RAID driver improvements Anup Patel <anup.patel@broadcom.com> - 2017-07-26 07:40 +0200
  [PATCH 1/6] dma: bcm-sba-raid: Improve memory allocation in SBA RAID driver Anup Patel <anup.patel@broadcom.com> - 2017-07-26 07:40 +0200
    Re: [PATCH 1/6] dma: bcm-sba-raid: Improve memory allocation in SBA  RAID driver Vinod Koul <vinod.koul@intel.com> - 2017-07-26 19:10 +0200
      Re: [PATCH 1/6] dma: bcm-sba-raid: Improve memory allocation in SBA  RAID driver Anup Patel <anup.patel@broadcom.com> - 2017-07-27 06:20 +0200
        Re: [PATCH 1/6] dma: bcm-sba-raid: Improve memory allocation in SBA  RAID driver Vinod Koul <vinod.koul@intel.com> - 2017-07-28 05:20 +0200
          Re: [PATCH 1/6] dma: bcm-sba-raid: Improve memory allocation in SBA  RAID driver Anup Patel <anup.patel@broadcom.com> - 2017-07-28 05:50 +0200
  [PATCH 2/6] dma: bcm-sba-raid: Peek mbox when we are left with no free requests Anup Patel <anup.patel@broadcom.com> - 2017-07-26 07:40 +0200
    Re: [PATCH 2/6] dma: bcm-sba-raid: Peek mbox when we are left with  no free requests Vinod Koul <vinod.koul@intel.com> - 2017-07-26 19:10 +0200
      Re: [PATCH 2/6] dma: bcm-sba-raid: Peek mbox when we are left with no  free requests Anup Patel <anup.patel@broadcom.com> - 2017-07-27 07:00 +0200
        Re: [PATCH 2/6] dma: bcm-sba-raid: Peek mbox when we are left with  no free requests Vinod Koul <vinod.koul@intel.com> - 2017-07-28 05:20 +0200
          Re: [PATCH 2/6] dma: bcm-sba-raid: Peek mbox when we are left with no  free requests Anup Patel <anup.patel@broadcom.com> - 2017-07-28 05:40 +0200
  [PATCH 6/6] arm64: dts: Add SBA-RAID DT nodes for Stingray SoC Anup Patel <anup.patel@broadcom.com> - 2017-07-26 07:40 +0200
  Re: [PATCH 0/6] Broadcom SBA-RAID driver improvements Vinod Koul <vinod.koul@intel.com> - 2017-07-26 19:10 +0200
    Re: [PATCH 0/6] Broadcom SBA-RAID driver improvements Anup Patel <anup.patel@broadcom.com> - 2017-07-27 06:10 +0200

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