x86/fpu: Print out whether we are doing lazy/eager FPU context switches
authorIngo Molnar <mingo@kernel.org>
Thu, 23 Apr 2015 09:26:08 +0000 (11:26 +0200)
committerIngo Molnar <mingo@kernel.org>
Tue, 19 May 2015 13:47:22 +0000 (15:47 +0200)
commit9a89b02918c03d91e685d06e49a652da5f35befc
treebf9aa672b04158abd0f37e1d2486bfcb9479831a
parentbfd6fc0581e7e2f3fa0b3e5e21cd6e54c3fbd16f
x86/fpu: Print out whether we are doing lazy/eager FPU context switches

Ever since the kernel started defaulting to eager FPU switches on modern Intel
CPUs it's not been obvious whether a given system is using the lazy or the eager
FPU context switching logic.

So generate a boot message about which mode the FPU code is in:

  x86/fpu: Using 'lazy' FPU context switches.

or:

  x86/fpu: Using 'eager' FPU context switches.

Reviewed-by: Borislav Petkov <bp@alien8.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
arch/x86/kernel/fpu/xsave.c