Subject: Re: [PATCH v1 1/3] cgroup/rstat: add cgroup_rstat_lock helpers and tracepoints

From: Jesper Dangaard Brouer <[email-masked]>
Date: Thu, 18 Apr 2024 10:00:17 +0200

On 16/04/2024 23.36, Tejun Heo wrote:
> On Tue, Apr 16, 2024 at 07:51:26PM +0200, Jesper Dangaard Brouer wrote:
>> This commit enhances the ability to troubleshoot the global
>> cgroup_rstat_lock by introducing wrapper helper functions for the lock
>> along with associated tracepoints.
> 
> Applied to cgroup/for-6.10.
> 

Thanks for applying the tracepoint patch. I've backported this to our 
main production kernels v6.6 LTS (with before mentioned upstream cgroup 
work from Yosry and Longman). I have it running in production on two 
machines this morning.  Doing manual bpftrace script inspection now, but 
plan is monitor this continuously (ebpf_exporter[1]) and even have 
alerts on excessive wait time on contention.

It makes sense to delay applying the next two patches, until we have 
some production experiments with those two patches, and I have fleet 
monitoring in place.  I'm be offline next week (on dive trip), so I'll 
resume work on this 29 April, before I start doing prod experiments.

--Jesper
[1] https://github.com/cloudflare/ebpf_exporter