From c5c19941ad1bb18f010ae47f1db333c00b276d55 Mon Sep 17 00:00:00 2001 From: "Kirill A. Shutemov" Date: Fri, 8 May 2015 13:25:45 +0300 Subject: [PATCH] x86/kconfig: Bump default NR_CPUS from 8 to 64 for 64-bit configuration Default NR_CPUS==8 is not enough to cover high-end desktop configuration: Haswell-E has upto 16 threads. Let's increase default NR_CPUS to 64 on 64-bit configuration. With this value CPU bitmask will still fit into one unsigned long. Default for 32-bit configuration is still 8: it's unlikely anybody will run 32-bit kernels on modern hardware. As an alternative we could bump NR_CPUS to 128 to cover all dual-processor servers with some margin. For reference: Debian and Suse build their kernels with NR_CPUS==512, Fedora -- 1024. Signed-off-by: Kirill A. Shutemov Cc: Andrew Morton Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/1431080745-19792-1-git-send-email-kirill.shutemov@linux.intel.com Signed-off-by: Ingo Molnar --- arch/x86/Kconfig | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 226d5696e1d1..83cd1c7aa409 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -851,7 +851,8 @@ config NR_CPUS default "1" if !SMP default "8192" if MAXSMP default "32" if SMP && X86_BIGSMP - default "8" if SMP + default "8" if SMP && X86_32 + default "64" if SMP ---help--- This allows you to specify the maximum number of CPUs which this kernel will support. If CPUMASK_OFFSTACK is enabled, the maximum -- 2.30.2