Commit-ID: 03eaec81ac09814817e9f0307d572ffe8365f980 Gitweb: http://git.kernel.org/tip/03eaec81ac09814817e9f0307d572ffe8365f980 Author: Andi Kleen <a...@linux.intel.com> AuthorDate: Sat, 23 Sep 2017 15:00:06 +0200 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Sun, 24 Sep 2017 13:04:35 +0200
x86/fpu: Turn WARN_ON() in context switch into WARN_ON_FPU() copy_xregs_to_kernel checks if the alternatives have been already patched. This WARN_ON() is always executed in every context switch. All the other checks in fpu internal.h are WARN_ON_FPU(), but this one is plain WARN_ON(). I assume it was forgotten to switch it. So switch it to WARN_ON_FPU() too to avoid some unnecessary code in the context switch, and a potentially expensive cache line miss for the global variable. Signed-off-by: Andi Kleen <a...@linux.intel.com> Cc: Andrew Morton <a...@linux-foundation.org> Cc: Andy Lutomirski <l...@amacapital.net> Cc: Borislav Petkov <b...@alien8.de> Cc: Dave Hansen <dave.han...@linux.intel.com> Cc: Eric Biggers <ebigge...@gmail.com> Cc: Fenghua Yu <fenghua...@intel.com> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Oleg Nesterov <o...@redhat.com> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Rik van Riel <r...@redhat.com> Cc: Thomas Gleixner <t...@linutronix.de> Cc: Yu-cheng Yu <yu-cheng...@intel.com> Link: http://lkml.kernel.org/r/20170329062605.4970-1-a...@firstfloor.org Link: http://lkml.kernel.org/r/20170923130016.21448-24-mi...@kernel.org Signed-off-by: Ingo Molnar <mi...@kernel.org> --- arch/x86/include/asm/fpu/internal.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/include/asm/fpu/internal.h b/arch/x86/include/asm/fpu/internal.h index 629e7abc..2dca7c6 100644 --- a/arch/x86/include/asm/fpu/internal.h +++ b/arch/x86/include/asm/fpu/internal.h @@ -350,7 +350,7 @@ static inline void copy_xregs_to_kernel(struct xregs_state *xstate) u32 hmask = mask >> 32; int err; - WARN_ON(!alternatives_patched); + WARN_ON_FPU(!alternatives_patched); XSTATE_XSAVE(xstate, lmask, hmask, err);
