From: Tejun Heo <tj@kernel.org>
To: "Michal Koutný" <mkoutny@suse.com>
Cc: cgroups@vger.kernel.org, linux-block@vger.kernel.org,
linux-kernel@vger.kernel.org, Josef Bacik <josef@toxicpanda.com>,
Jens Axboe <axboe@kernel.dk>,
Johannes Weiner <hannes@cmpxchg.org>,
Waiman Long <longman@redhat.com>
Subject: Re: [PATCH 4/9] cgroup: Print warning when /proc/cgroups is read on v2-only system
Date: Tue, 4 Mar 2025 06:55:02 -1000 [thread overview]
Message-ID: <Z8cwZluJooqbO7uZ@slm.duckdns.org> (raw)
In-Reply-To: <20250304153801.597907-5-mkoutny@suse.com>
On Tue, Mar 04, 2025 at 04:37:56PM +0100, Michal Koutný wrote:
> As a followup to commits 6c2920926b10e ("cgroup: replace
> unified-hierarchy.txt with a proper cgroup v2 documentation") and
> ab03125268679 ("cgroup: Show # of subsystem CSSes in cgroup.stat"),
> add a runtime message to users who read status of controllers in
> /proc/cgroups on v2-only system. The detection is based on a)
> no controllers are attached to v1, b) default hierarchy is mounted (the
> latter is for setups that neven mount v2 but read /proc/cgroups upon
> boot when controllers default to v2).
I'm hoping that we could deprecate /proc/cgroups entirely. Maybe we can just
warn whenever the file is accessed?
Thanks.
--
tejun
next prev parent reply other threads:[~2025-03-04 16:55 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-03-04 15:37 [PATCH 0/9] cgroup v1 deprecation warnings Michal Koutný
2025-03-04 15:37 ` [PATCH 1/9] cgroup/cpuset-v1: Add deprecation warnings to sched_load_balance and memory_pressure_enabled Michal Koutný
2025-03-04 16:19 ` Waiman Long
2025-03-04 16:52 ` Tejun Heo
2025-03-04 17:10 ` Michal Koutný
2025-03-04 17:33 ` Waiman Long
2025-03-04 18:04 ` Tejun Heo
2025-03-05 10:12 ` Michal Koutný
2025-03-05 18:39 ` Tejun Heo
2025-03-04 15:37 ` [PATCH 2/9] cgroup/cpuset-v1: Add deprecation warnings to memory_spread_page and memory_spread_slab Michal Koutný
2025-03-04 15:37 ` [PATCH 3/9] cgroup/blkio: Add deprecation warnings to reset_stats Michal Koutný
2025-03-04 15:37 ` [PATCH 4/9] cgroup: Print warning when /proc/cgroups is read on v2-only system Michal Koutný
2025-03-04 16:55 ` Tejun Heo [this message]
2025-03-05 10:17 ` Michal Koutný
2025-03-05 16:27 ` Waiman Long
2025-03-04 15:37 ` [PATCH 5/9] RFC cgroup/cpuset-v1: Add deprecation warnings to mem_exclusive and mem_hardwall Michal Koutný
2025-03-04 15:37 ` [PATCH 6/9] RFC cgroup/cpuset-v1: Add deprecation warnings to memory_migrate Michal Koutný
2025-03-04 15:37 ` [PATCH 7/9] RFC cgroup/cpuset-v1: Add deprecation warnings to sched_relax_domain_level Michal Koutný
2025-03-04 15:38 ` [PATCH 8/9] cgroup: Update file naming comment Michal Koutný
2025-03-04 15:38 ` [PATCH 9/9] blk-cgroup: Simplify policy files registration Michal Koutný
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