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Miller" , Eric Dumazet , Gabriele Monaco , Greg Kroah-Hartman , Ingo Molnar , Jakub Kicinski , Jens Axboe , Johannes Weiner , Lai Jiangshan , Marco Crivellari , Michal Hocko , Muchun Song , Paolo Abeni , Peter Zijlstra , Phil Auld , "Rafael J . Wysocki" , Roman Gushchin , Shakeel Butt , Simon Horman , Tejun Heo , Thomas Gleixner , Vlastimil Babka , Waiman Long , Will Deacon , cgroups@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-block@vger.kernel.org, linux-mm@kvack.org, linux-pci@vger.kernel.org, netdev@vger.kernel.org Subject: [PATCH 10/31] cpu: Provide lockdep check for CPU hotplug lock write-held Date: Wed, 5 Nov 2025 22:03:26 +0100 Message-ID: <20251105210348.35256-11-frederic@kernel.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20251105210348.35256-1-frederic@kernel.org> References: <20251105210348.35256-1-frederic@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: 489731C0011 X-Rspamd-Server: rspam07 X-Stat-Signature: 9hiqwuzytt4bsuqjsj4pce4pe1h61c5q X-Rspam-User: X-HE-Tag: 1762376722-322673 X-HE-Meta: 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 Fj88F2tl egfPEy0HgrKksCc1SO7/Xj5YduNG/CM7RatHYCu+Gqjr/So4UHe6vd/n2Jmkh4zaj2PUp+UOPl4AVEq8e84q/dPZY74KklK3uCicwA8tMMdDFWsaXXUjXx6S/qSZ8IuGT0KQa5E6YnYNd/WYAcYDX4XFHsFlHg4thH+kCi8DWA4eLrO6mt5BC7we3Owv8p/X4SJaAIHY/5knzDlcMC1vMj/NXK5UuqC/pcZQXTRsZWyRfjT3uMYBJaZ04A0bvX+9WqCG2JBYJUJEjBs4= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: cpuset modifies partitions, including isolated, while holding the cpu hotplug lock read-held. This means that write-holding the CPU hotplug lock is safe to synchronize against housekeeping cpumask changes. Provide a lockdep check to validate that. Signed-off-by: Frederic Weisbecker --- include/linux/cpuhplock.h | 1 + include/linux/percpu-rwsem.h | 1 + kernel/cpu.c | 5 +++++ 3 files changed, 7 insertions(+) diff --git a/include/linux/cpuhplock.h b/include/linux/cpuhplock.h index f7aa20f62b87..286b3ab92e15 100644 --- a/include/linux/cpuhplock.h +++ b/include/linux/cpuhplock.h @@ -13,6 +13,7 @@ struct device; extern int lockdep_is_cpus_held(void); +extern int lockdep_is_cpus_write_held(void); #ifdef CONFIG_HOTPLUG_CPU void cpus_write_lock(void); diff --git a/include/linux/percpu-rwsem.h b/include/linux/percpu-rwsem.h index 288f5235649a..c8cb010d655e 100644 --- a/include/linux/percpu-rwsem.h +++ b/include/linux/percpu-rwsem.h @@ -161,6 +161,7 @@ extern void percpu_free_rwsem(struct percpu_rw_semaphore *); __percpu_init_rwsem(sem, #sem, &rwsem_key); \ }) +#define percpu_rwsem_is_write_held(sem) lockdep_is_held_type(sem, 0) #define percpu_rwsem_is_held(sem) lockdep_is_held(sem) #define percpu_rwsem_assert_held(sem) lockdep_assert_held(sem) diff --git a/kernel/cpu.c b/kernel/cpu.c index 453a806af2ee..3b0443f7c486 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -534,6 +534,11 @@ int lockdep_is_cpus_held(void) { return percpu_rwsem_is_held(&cpu_hotplug_lock); } + +int lockdep_is_cpus_write_held(void) +{ + return percpu_rwsem_is_write_held(&cpu_hotplug_lock); +} #endif static void lockdep_acquire_cpus_lock(void) -- 2.51.0