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| author | Yury Norov <yury.norov@gmail.com> | 2022-10-19 15:59:39 -0700 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2022-10-24 17:21:51 -0700 |
| commit | a62118fb0e3e54d114a2f44b8069e0463db9f7b7 (patch) | |
| tree | afb7de2e4d1c1174588ec0db5dfab4c2e4a58a72 | |
| parent | 01344551cc7cc2e7fd77d906730d523ac296c063 (diff) | |
| download | linux-a62118fb0e3e54d114a2f44b8069e0463db9f7b7.tar.gz linux-a62118fb0e3e54d114a2f44b8069e0463db9f7b7.tar.xz | |
cpumask: limit visibility of FORCE_NR_CPUS
In current form, FORCE_NR_CPUS is visible to all users building their
kernels, even not experts. It is also set in allmodconfig or
allyesconfig, which is not a correct behavior.
The 'choice' and unused config UNFORCE_NR_CPUS are used to ensure that
auto-generated configs that try to enable as much options as possible,
like allmodconfig, don't enable FORCE_NR_CPUS.
Link: https://lkml.kernel.org/r/20221019225939.1646349-1-yury.norov@gmail.com
Signed-off-by: Yury Norov <yury.norov@gmail.com>
Suggested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Alexey Klimov <klimov.linux@gmail.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Eric Biggers <ebiggers@google.com>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Sander Vanheule <sander@svanheule.net>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Valentin Schneider <vschneid@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| -rw-r--r-- | lib/Kconfig | 31 |
1 files changed, 24 insertions, 7 deletions
diff --git a/lib/Kconfig b/lib/Kconfig index 9bbf8a4b2108..3d8382bbc331 100644 --- a/lib/Kconfig +++ b/lib/Kconfig @@ -528,14 +528,31 @@ config CPUMASK_OFFSTACK them on the stack. This is a bit more expensive, but avoids stack overflow. +choice + prompt "Number of CPUs detection method" + default UNFORCE_NR_CPUS + depends on SMP && EXPERT + help + Select between boot-time and compile-time detection of number + of CPUs. If it's possible to provide exact number of CPUs at + compile-time, kernel code may be optimized better. + For general-purpose kernel, choose "boot time" option. + +config UNFORCE_NR_CPUS + bool "Set number of CPUs at boot time" + help + Choose it if you build general-purpose kernel and want to rely + on kernel to detect actual number of CPUs. + config FORCE_NR_CPUS - bool "NR_CPUS is set to an actual number of CPUs" - depends on SMP - help - Say Yes if you have NR_CPUS set to an actual number of possible - CPUs in your system, not to a default value. This forces the core - code to rely on compile-time value and optimize kernel routines - better. + bool "Set number of CPUs at compile time" + help + Choose it if NR_CPUS corresponds to an actual number of + possible CPUs in your system. This forces the core code + to rely on compile-time value and optimize kernel routines + better. + +endchoice config CPU_RMAP bool |