Re: [PATCH] powerpc/powernv: Turn on SCSI_AACRAID in powernv_defconfig

[Stewart Smith <stewart@linux.vnet.ibm.com>]

Michael Ellerman <mpe@ellerman.id.au> writes:
> Brian King <brking@linux.vnet.ibm.com> writes:
>> On 09/03/2017 06:19 PM, Stewart Smith wrote:
>>> Michael Ellerman <mpe@ellerman.id.au> writes:
>>>>> 2. On a bare metal machine, if you set ipr.fast_reboot=1 on the skiboot
>>>>>    kernel, then we should also avoid resetting the ipr adapter, so ipr
>>>>>    init on the kernel being kexec booted from skiboot should be extremely fast. 
>>>>
>>>> OK, I didn't know that was an option, so that might help.
>>>>
>>>>> ...
>>>>> If you've got cases where ipr init is taking a long time, I'd be
>>>>> interested to know what scenarios are the most annoying to see if there
>>>>> is any opportunity to improve.
>>>>
>>>> Yeah booting bare metal is where I see it (not using ipr.fast_reboot).
>>> 
>>> Hrm... We should probably enable that by default for petitboot then.
>>> 
>>> It'd at least cut some time off booting straight through to OS.
>>
>> Agreed. I'd be interested to hear if that helps address the issue
>> Michael is seeing.
>>
>> You can easily test this by exiting to a petitboot shell:
>>
>> echo 1 > /sys/module/ipr/parameters/fast_reboot
>>
>> Then go back to petitboot and boot the OS.
>
> Just following up on this (!).
>
> This does work, and I've now been running it in my CI for about a month
> (~1000 boots) with no problems.
>
> You can also make it persistent by doing:
>
>   $ nvram -p ibm,skiboot --update-config bootargs="ipr.fast_reboot=1"

Okay, cool. https://github.com/open-power/op-build/pull/1900 will set it
in firmware - we may as well run with this and fix any bugs we find.

Any reason why it isn't the default behaviour?

-- 
Stewart Smith
OPAL Architect, IBM.