Commit a7e54635 authored May 27, 2025 by Frederic Weisbecker

cpuset: Provide lockdep check for cpuset lock held



cpuset modifies partitions, including isolated, while holding the cpuset
mutex.

This means that holding the cpuset mutex is safe to synchronize against
housekeeping cpumask changes.

Provide a lockdep check to validate that.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Cc: "Michal Koutný" <mkoutny@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Marco Crivellari <marco.crivellari@suse.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Waiman Long <longman@redhat.com>
Cc: cgroups@vger.kernel.org
Cc: linux-kernel@vger.kernel.org

parent 622c508b

include/linux/cpuset.h

+2 −0

Original line number	Diff line number	Diff line
		@@ -18,6 +18,8 @@
		#include <linux/mmu_context.h>
		#include <linux/jump_label.h>

		extern bool lockdep_is_cpuset_held(void);

		#ifdef CONFIG_CPUSETS

		/*

kernel/cgroup/cpuset.c

+7 −0

Original line number	Diff line number	Diff line
		@@ -283,6 +283,13 @@ void cpuset_full_unlock(void)
		cpus_read_unlock();
		}

		#ifdef CONFIG_LOCKDEP
		bool lockdep_is_cpuset_held(void)
		{
		return lockdep_is_held(&cpuset_mutex);
		}
		#endif

		static DEFINE_SPINLOCK(callback_lock);

		void cpuset_callback_lock_irq(void)