Re: [PATCH] net: sched: don't disable bh when accessing action idr

From: Vlad Buslov <redacted>
Date: Sat, 19 May 2018 13:12:49 +0300

On Sat 19 May 2018 at 02:59, Cong Wang [off-list ref] wrote:

quoted

On Fri, May 18, 2018 at 8:45 AM, Vlad Buslov [off-list ref] wrote:

quoted

Underlying implementation of action map has changed and doesn't require
disabling bh anymore. Replace all action idr spinlock usage with regular
calls that do not disable bh.

Please explain explicitly why it is not required, don't let people
dig, this would save everyone's time.

Underlying implementation of actions lookup has changed from hashtable
to idr. Every current action implementation just calls act_api lookup
function instead of implementing its own lookup. I asked author of idr
change if there is a reason to continue to use _bh versions and he
replied that he just left them as-is.

A detailed analysis of the locking requirements both before and
after the IDR changes needs to be in you commit message.

Nobody who reads this from scratch understands all of this background
material, so how can anyone reading your patch review it properly and
understand it?