Re: [PATCH] proc: Disable /proc/$pid/wchan

From: Peter Zijlstra
Date: Wed Sep 29 2021 - 04:51:47 EST

On Fri, Sep 24, 2021 at 02:54:24PM +0100, Mark Rutland wrote:
> We could instead have the scheduler entrypoints snapshot their caller
> into a field in task_struct. If there are sufficiently few callers, that
> could be an inline wrapper that passes a __func__ string. Otherwise, we
> still need to symbolize.

I strongly dislike that option, we'd make the scheduler slower for
something that's typically unused.

The 3 people actually using wchan should pay the cost of obtaining the
data, not everybody all the time.