On Mon, Oct 23, 2017, 3:13 PM Hans de Goede <hdegoede@redhat.com> wrote:
Hi,

On 21-10-17 20:50, Kevin Fenzi wrote:
> On 09/14/2017 04:22 AM, Hans de Goede wrote:
>> Hi All,
>>
>> My next project for Red Hat is to work on improving Linux laptop battery
>> life.
>> Part of the (hopefully) low hanging fruit here is using kernel tunables to
>> enable more runtime powermanagement. My first target here is SATA Link
>> Power
>> Management (LPM) which, as Matthew Garrett blogged about 2 years ago:
>> https://mjg59.dreamwidth.org/34868.html
>> can lead to a significant improvement in battery life.
>>
>> There is only one small problem, there have been some reports that some
>> disks/SSDs don't play well with Linux' min_power LPM policy and that this
>> may lead to system crashes and even data corruption.
>>
>> As such I've written a new LPM policy, which matches the power-management
>> defaults from the Intel RST Windows drivers. Since it mimicks Windows,
>> this new policy will hopefully not hit any SSD firmware bugs like min_power
>> sometimes does.
>>
>> So now I'm looking for people with a laptop with a SATA SSD or HDD to help
>> me test this to make sure this won't cause any issues when we enable this
>> by default for F28, for more details and test instructions see:
>>
>> https://hansdegoede.livejournal.com/18412.html
>
> Hey Hans. I had marked this to try and do to help gather info, but
> things have been busy and I haven't ever gotten to it.
>
> I thought before I did I might ask if you already have the info you were
> looking for since it's been over a month now.
>
> How have reports been? Is it perhaps time to enable this in rawhide?

I've had successful test reports from 10 people, of which 1 person
was actually seeing data corruption on his ssd with min_power and not
with the new med_power_with_dipm policy my patches add, which is good
news really :)

But 10 testers is not that much, so if you still feel like testing this,
then some more testing would definitely be welcome.

I'm curious what the manifestation of corruption is, and whether any on the 10 were using Btrfs? 


Chris Murphy