Re: [PATCH 1/1] sched: remove the redundant 'success' in the sched tracepoint

From: Ed Tsai
Date: Thu Apr 22 2021 - 20:40:23 EST


On Thu, 2021-04-22 at 11:46 -0400, Steven Rostedt wrote:
> On Thu, 22 Apr 2021 20:22:26 +0800
> Ed Tsai <ed.tsai@xxxxxxxxxxxx> wrote:
>
> > 'success' is left here for a long time and also it is meaningless
> > for the upper user. Just remove it.
>
> Have you tested all userspace code that might use this?
>
> This is the "poster boy" example of why Peter Zijlstra hates trace
> events ;-)
>
> I know I've updated trace-cmd to check to see if this field exits
> before
> depending on it, but there may be some other tools that may not.
> Perhaps
> nothing will break.
>
> I'm all for this change, but be ware, it might be reverted if there's
> some
> tool out that that expects it to exist. This is why it hasn't been
> removed.
>
> -- Steve

It is left here over 5 years. Old userspace code need this entry and
also someone may use it for a new tool. I hate this but it is a problem
should be resolved for the kernel or ignore just fine.