Re: [PATCH] oom, trace: Remove ENUM evaluation of COMPACTION_FEEDBACK

From: Steven Rostedt
Date: Thu Jun 15 2017 - 07:48:21 EST


On Thu, 15 Jun 2017 12:57:21 +0200
Michal Hocko <mhocko@xxxxxxxxxx> wrote:

> > #define COMPACTION_FEEDBACK \
> > EM(COMPACTION_FAILED, "failed") \
> > EM(COMPACTION_WITHDRAWN, "withdrawn") \
> > EMe(COMPACTION_PROGRESS, "progress")
> >
> > Which is still needed for the __print_symbolic() usage in the
> > trace_event. But it is not needed to be evaluated.
> >
> > Removing the evaluation part removes the unnecessary evaluations of
> > numbers to numbers.
>
> I will be honest with you. Even if I understood how this voodoo mapping
> works I forgot everything. So if the COMPACTION_*->names keeps working
> I have no objection to the patch.

Yes it does. It you want to verify, simply boot the kernel without the
patch and do:

# cat /sys/kernel/debug/tracing/events/*/*/format > ~/formats1

Add the patch, compile and boot that kernel.

# cat /sys/kernel/debug/tracing/events/*/*/format > ~/formats2

then:

# diff formats1 formats2

and they should be the same, with the exception that the ID:'s can
change.

Also, let me send a v2. Resending this patch (from the private one)
seems to broke the format of it.

-- Steve