Re: [PATCH RFC smp] Remove diagnostics and adjust config for CSD lock diagnostics

From: Peter Zijlstra
Date: Tue Mar 21 2023 - 06:22:46 EST


On Mon, Mar 20, 2023 at 05:54:39PM -0700, Paul E. McKenney wrote:
> Hello!
>
> This series removes CSD-lock diagnostics that were once very useful
> but which have not seen much action since. It also adjusts Kconfig and
> kernel-boot-parameter setup.
>
> 1. locking/csd_lock: Add Kconfig option for csd_debug default.
>
> 2. locking/csd_lock: Remove added data from CSD lock debugging.
>
> 3. locking/csd_lock: Remove per-CPU data indirection from CSD
> lock debugging.
>
> 4. kernel/smp: Make csdlock_debug= resettable.
>
> Thanx, Paul
>
> ------------------------------------------------------------------------
>
> Documentation/admin-guide/kernel-parameters.txt | 17 -
> b/Documentation/admin-guide/kernel-parameters.txt | 6
> b/kernel/smp.c | 2
> b/lib/Kconfig.debug | 9
> kernel/smp.c | 260 ++--------------------
> 5 files changed, 47 insertions(+), 247 deletions(-)

Yay!! How do you want to route these, should I take them through tip?

What about the rest of the thing? Your commits seem to suggest it's
still actually used -- why? Are there still more virt bugs?