x86/fpu: Remove struct fpu::counter

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 <riel@redhat.com>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: pbonzini@redhat.com
Link: http://lkml.kernel.org/r/1475627678-20788-6-git-send-email-riel@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Daniel Sangorrin <daniel.sangorrin@toshiba.co.jp>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/x86/include/asm/fpu/internal.h b/arch/x86/include/asm/fpu/internal.h
index 2ff03cca92547762df852e21a7b64e38f5c1921c..16825dda18dcb7ca531ccdd9a3bef2baaefcf7e8 100644 (file)
--- a/arch/x86/include/asm/fpu/internal.h
+++ b/arch/x86/include/asm/fpu/internal.h
@@ -575,15 +575,12 @@ switch_fpu_prepare(struct fpu *old_fpu, struct fpu *new_fpu, int cpu)
 
                /* Don't change CR0.TS if we just switch! */
                if (fpu.preload) {
-                       new_fpu->counter++;
                        __fpregs_activate(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

diff --git a/arch/x86/include/asm/fpu/types.h b/arch/x86/include/asm/fpu/types.h
index 1c6f6ac52ad0a2cfe44db5eab9825b59408cde01..dcb85a9ac9b47f903058af7c85903cf81378f527 100644 (file)
--- a/arch/x86/include/asm/fpu/types.h
+++ b/arch/x86/include/asm/fpu/types.h
@@ -302,17 +302,6 @@ 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:
         *

diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c
index b282364c075c4cbbb0b9a3736b3b3e0fcdb67786..b322325424bc022120b440b91e004bf842eed8a2 100644 (file)
--- a/arch/x86/kernel/fpu/core.c
+++ b/arch/x86/kernel/fpu/core.c
@@ -250,7 +250,6 @@ static void fpu_copy(struct fpu *dst_fpu, struct fpu *src_fpu)
 
 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;
 
@@ -353,7 +352,6 @@ void fpu__restore(struct fpu *fpu)
        kernel_fpu_disable();
        fpregs_activate(fpu);
        copy_kernel_to_fpregs(&fpu->state);
-       fpu->counter++;
        kernel_fpu_enable();
 }
 EXPORT_SYMBOL_GPL(fpu__restore);
@@ -370,7 +368,6 @@ 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 */