4.9-stable review patch. If anyone has any objections, please let me know.
------------------ From: Rik van Riel <[email protected]> commit 3913cc3507575273beb165a5e027a081913ed507 upstream. With the lazy FPU code gone, we no longer use the counter field in struct fpu for anything. Get rid it. Signed-off-by: Rik van Riel <[email protected]> Reviewed-by: Andy Lutomirski <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Brian Gerst <[email protected]> Cc: Dave Hansen <[email protected]> Cc: Denys Vlasenko <[email protected]> Cc: Fenghua Yu <[email protected]> Cc: H. Peter Anvin <[email protected]> Cc: Josh Poimboeuf <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Oleg Nesterov <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Quentin Casasnovas <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]> Cc: Daniel Sangorrin <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- arch/x86/include/asm/fpu/internal.h | 3 --- arch/x86/include/asm/fpu/types.h | 11 ----------- arch/x86/include/asm/trace/fpu.h | 5 +---- arch/x86/kernel/fpu/core.c | 3 --- 4 files changed, 1 insertion(+), 21 deletions(-) --- a/arch/x86/include/asm/fpu/internal.h +++ b/arch/x86/include/asm/fpu/internal.h @@ -581,16 +581,13 @@ switch_fpu_prepare(struct fpu *old_fpu, /* Don't change CR0.TS if we just switch! */ if (fpu.preload) { - new_fpu->counter++; __fpregs_activate(new_fpu); trace_x86_fpu_regs_activated(new_fpu); prefetch(&new_fpu->state); } } else { - old_fpu->counter = 0; old_fpu->last_cpu = -1; if (fpu.preload) { - new_fpu->counter++; if (fpu_want_lazy_restore(new_fpu, cpu)) fpu.preload = 0; else --- a/arch/x86/include/asm/fpu/types.h +++ b/arch/x86/include/asm/fpu/types.h @@ -322,17 +322,6 @@ struct fpu { unsigned char fpregs_active; /* - * @counter: - * - * This counter contains the number of consecutive context switches - * during which the FPU stays used. If this is over a threshold, the - * lazy FPU restore logic becomes eager, to save the trap overhead. - * This is an unsigned char so that after 256 iterations the counter - * wraps and the context switch behavior turns lazy again; this is to - * deal with bursty apps that only use the FPU for a short time: - */ - unsigned char counter; - /* * @state: * * In-memory copy of all FPU registers that we save/restore --- a/arch/x86/include/asm/trace/fpu.h +++ b/arch/x86/include/asm/trace/fpu.h @@ -14,7 +14,6 @@ DECLARE_EVENT_CLASS(x86_fpu, __field(struct fpu *, fpu) __field(bool, fpregs_active) __field(bool, fpstate_active) - __field(int, counter) __field(u64, xfeatures) __field(u64, xcomp_bv) ), @@ -23,17 +22,15 @@ DECLARE_EVENT_CLASS(x86_fpu, __entry->fpu = fpu; __entry->fpregs_active = fpu->fpregs_active; __entry->fpstate_active = fpu->fpstate_active; - __entry->counter = fpu->counter; if (boot_cpu_has(X86_FEATURE_OSXSAVE)) { __entry->xfeatures = fpu->state.xsave.header.xfeatures; __entry->xcomp_bv = fpu->state.xsave.header.xcomp_bv; } ), - TP_printk("x86/fpu: %p fpregs_active: %d fpstate_active: %d counter: %d xfeatures: %llx xcomp_bv: %llx", + TP_printk("x86/fpu: %p fpregs_active: %d fpstate_active: %d xfeatures: %llx xcomp_bv: %llx", __entry->fpu, __entry->fpregs_active, __entry->fpstate_active, - __entry->counter, __entry->xfeatures, __entry->xcomp_bv ) --- a/arch/x86/kernel/fpu/core.c +++ b/arch/x86/kernel/fpu/core.c @@ -225,7 +225,6 @@ EXPORT_SYMBOL_GPL(fpstate_init); int fpu__copy(struct fpu *dst_fpu, struct fpu *src_fpu) { - dst_fpu->counter = 0; dst_fpu->fpregs_active = 0; dst_fpu->last_cpu = -1; @@ -433,7 +432,6 @@ void fpu__restore(struct fpu *fpu) trace_x86_fpu_before_restore(fpu); fpregs_activate(fpu); copy_kernel_to_fpregs(&fpu->state); - fpu->counter++; trace_x86_fpu_after_restore(fpu); kernel_fpu_enable(); } @@ -451,7 +449,6 @@ EXPORT_SYMBOL_GPL(fpu__restore); void fpu__drop(struct fpu *fpu) { preempt_disable(); - fpu->counter = 0; if (fpu->fpregs_active) { /* Ignore delayed exceptions from user space */
