Viresh Kumar wrote:

On 5 August 2014 01:46, Saravana Kannan [off-list ref] wrote:

quoted

The problem is when between one thread trying to cat a governor's file
(say,
sampling_rate) vs the governor getting a POLICY_EXIT.

I don't see two threads racing against each other here. Simply changing
the governor from conservative->ondemand creates this.

Or is it that the kernel is detecting two different orders of taking lock?

But during governor change, isn't the sysfs lock taken first as we are
storing a value to "scaling_governor"? So, isn't this a sysfs lock first
in all cases?

In short, I am still unclear about the *exact* problem here.

quoted

Could you please look at my policy free/remove patches? If you can do
that,
I can work on a fix for this. It might also be simpler to fix after my
patch
series (not sure, might be).

I had an overall look of those on the day you posted them, but haven't
commented yet as was going away..

There is no way those can land in 3.17-rc1 atleast and so we still have
some time to get them pushed..

Anyway, they are my number two priority and the number one is this bug,
which we have to fix in stable kernels as well. So, a dependency on your
series wouldn't work..

Sigh... ok. I too will try to fix this one. I already have something in
mind for this.

Looks like Srivatsa has gone off the grid too. I'm hoping at least one of
you can do a review of my series. Come on guys, not everyone has to work
on the same patch/issue. :-(

-Saravana

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