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| author | Alexander Sverdlin <alexander.sverdlin@siemens.com> | 2022-12-12 17:37:15 +0100 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2023-01-11 19:45:26 +0100 |
| commit | 379af13b31fa8a36ad4abd59a5c511f25c5d4d42 (patch) | |
| tree | ef5e8b47f5ec5874b752d097b3ac766a977fae6d /Documentation/kernel-hacking | |
| parent | 17549b0f184d870f2cfa4e5cfa79f4c4905ed757 (diff) | |
| download | linux-379af13b31fa8a36ad4abd59a5c511f25c5d4d42.tar.gz | |
docs: locking: Discourage from calling disable_irq() in atomic
Correct the example in the documentation so that disable_irq() is not being
called in atomic context.
disable_irq() calls sleeping synchronize_irq(), it's not allowed to call
them in atomic context.
Signed-off-by: Alexander Sverdlin <alexander.sverdlin@siemens.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Manfred Spraul <manfred@colorfullife.com>
Cc: linux-doc@vger.kernel.org
Link: https://lore.kernel.org/lkml/87k02wbs2n.ffs@tglx/
Link: https://lore.kernel.org/r/20221212163715.830315-1-alexander.sverdlin@siemens.com
Diffstat (limited to 'Documentation/kernel-hacking')
| -rw-r--r-- | Documentation/kernel-hacking/locking.rst | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/Documentation/kernel-hacking/locking.rst b/Documentation/kernel-hacking/locking.rst index c756786e17aea3..dff0646a717bff 100644 --- a/Documentation/kernel-hacking/locking.rst +++ b/Documentation/kernel-hacking/locking.rst @@ -1277,11 +1277,11 @@ Manfred Spraul points out that you can still do this, even if the data is very occasionally accessed in user context or softirqs/tasklets. The irq handler doesn't use a lock, and all other accesses are done as so:: - spin_lock(&lock); + mutex_lock(&lock); disable_irq(irq); ... enable_irq(irq); - spin_unlock(&lock); + mutex_unlock(&lock); The disable_irq() prevents the irq handler from running (and waits for it to finish if it's currently running on other CPUs). |