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20f8932f97
Using get_cpu() leads to disabling preemption and in this context it is not
possible to acquire the following spinlock_t on PREEMPT_RT because it
becomes a sleeping lock.
Commit 0ea5c27583 ("[SCSI] bnx2fc: common free list for cleanup
commands") says that it is using get_cpu() as a fix in case the CPU is
preempted. While this might be true, the important part is that it is now
using the same CPU for locking and unlocking while previously it always
relied on smp_processor_id(). The date structure itself is protected with
a lock so it does not rely on CPU-local access.
Replace get_cpu() with raw_smp_processor_id() to obtain the current CPU
number which is used as an index for the per-CPU resource.
Link: https://lore.kernel.org/r/20220506105758.283887-5-bigeasy@linutronix.de
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.