[merged mm-nonmm-stable] cpumask-add-up-optimised-for_each__cpu-versions.patch removed from -mm tree

[merged mm-nonmm-stable] cpumask-add-up-optimised-for_each__cpu-versions.patch removed from -mm tree

[Andrew Morton]

The quilt patch titled
     Subject: cpumask: add UP optimised for_each_*_cpu versions
has been removed from the -mm tree.  Its filename was
     cpumask-add-up-optimised-for_each__cpu-versions.patch

This patch was dropped because it was merged into the mm-nonmm-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

------------------------------------------------------
From: Sander Vanheule <sander@svanheule.net>
Subject: cpumask: add UP optimised for_each_*_cpu versions
Date: Sat, 2 Jul 2022 18:08:27 +0200

On uniprocessor builds, the following loops will always run over a mask
that contains one enabled CPU (cpu0):

    - for_each_possible_cpu
    - for_each_online_cpu
    - for_each_present_cpu

Provide uniprocessor-specific macros for these loops, that always run
exactly once.

Link: https://lkml.kernel.org/r/3a92869b902a075b97be5d1452c9c6badbbff0df.1656777646.git.sander@svanheule.net
Signed-off-by: Sander Vanheule <sander@svanheule.net>
Acked-by: Yury Norov <yury.norov@gmail.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Marco Elver <elver@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Valentin Schneider <vschneid@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 include/linux/cpumask.h |    7 +++++++
 1 file changed, 7 insertions(+)

--- a/include/linux/cpumask.h~cpumask-add-up-optimised-for_each__cpu-versions
+++ a/include/linux/cpumask.h
@@ -811,9 +811,16 @@ extern const DECLARE_BITMAP(cpu_all_bits
 /* First bits of cpu_bit_bitmap are in fact unset. */
 #define cpu_none_mask to_cpumask(cpu_bit_bitmap[0])
 
+#if NR_CPUS == 1
+/* Uniprocessor: the possible/online/present masks are always "1" */
+#define for_each_possible_cpu(cpu)	for ((cpu) = 0; (cpu) < 1; (cpu)++)
+#define for_each_online_cpu(cpu)	for ((cpu) = 0; (cpu) < 1; (cpu)++)
+#define for_each_present_cpu(cpu)	for ((cpu) = 0; (cpu) < 1; (cpu)++)
+#else
 #define for_each_possible_cpu(cpu) for_each_cpu((cpu), cpu_possible_mask)
 #define for_each_online_cpu(cpu)   for_each_cpu((cpu), cpu_online_mask)
 #define for_each_present_cpu(cpu)  for_each_cpu((cpu), cpu_present_mask)
+#endif
 
 /* Wrappers for arch boot code to manipulate normally-constant masks */
 void init_cpu_present(const struct cpumask *src);
_

Patches currently in -mm which might be from sander@svanheule.net are