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authorAlexander Sverdlin <alexander.sverdlin@siemens.com>2022-12-12 19:37:15 +0300
committerThomas Gleixner <tglx@linutronix.de>2023-01-11 21:45:26 +0300
commit379af13b31fa8a36ad4abd59a5c511f25c5d4d42 (patch)
treeef5e8b47f5ec5874b752d097b3ac766a977fae6d /Documentation/kernel-hacking/locking.rst
parent17549b0f184d870f2cfa4e5cfa79f4c4905ed757 (diff)
downloadlinux-379af13b31fa8a36ad4abd59a5c511f25c5d4d42.tar.xz
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/locking.rst')
-rw-r--r--Documentation/kernel-hacking/locking.rst4
1 files changed, 2 insertions, 2 deletions
diff --git a/Documentation/kernel-hacking/locking.rst b/Documentation/kernel-hacking/locking.rst
index c756786e17ae..dff0646a717b 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).