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58b4fba81a
Use atomic_long_try_cmpxchg() instead of atomic_long_cmpxchg (*ptr, old, new) == old in atomic_long_inc_below(). x86 CMPXCHG instruction returns success in ZF flag, so this change saves a compare after cmpxchg (and related move instruction in front of cmpxchg). Also, atomic_long_try_cmpxchg implicitly assigns old *ptr value to "old" when cmpxchg fails, enabling further code simplifications. No functional change intended. Link: https://lkml.kernel.org/r/20250721174610.28361-2-ubizjak@gmail.com Signed-off-by: Uros Bizjak <ubizjak@gmail.com> Reviewed-by: Alexey Gladkov <legion@kernel.org> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: "Paul E. McKenney" <paulmck@kernel.org> Cc: Alexey Gladkov <legion@kernel.org> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: MengEn Sun <mengensun@tencent.com> Cc: "Thomas Weißschuh" <linux@weissschuh.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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 reStructuredText 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.