x86/fpu: Move thread_info::fpu_counter into thread_info::fpu.counter

This field is kept separate from the main FPU state structure for
no good reason.

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>

diff --git a/arch/x86/include/asm/fpu-internal.h b/arch/x86/include/asm/fpu-internal.h
index 02e0e97..f85d21b 100644 (file)
--- a/arch/x86/include/asm/fpu-internal.h
+++ b/arch/x86/include/asm/fpu-internal.h
@@ -384,7 +384,7 @@ static inline void drop_fpu(struct task_struct *tsk)
         * Forget coprocessor state..
         */
        preempt_disable();
-       tsk->thread.fpu_counter = 0;
+       tsk->thread.fpu.counter = 0;
 
        if (__thread_has_fpu(tsk)) {
                /* Ignore delayed exceptions from user space */
@@ -441,7 +441,7 @@ static inline fpu_switch_t switch_fpu_prepare(struct task_struct *old, struct ta
         * or if the past 5 consecutive context-switches used math.
         */
        fpu.preload = tsk_used_math(new) &&
-                     (use_eager_fpu() || new->thread.fpu_counter > 5);
+                     (use_eager_fpu() || new->thread.fpu.counter > 5);
 
        if (__thread_has_fpu(old)) {
                if (!__save_init_fpu(old))
@@ -454,16 +454,16 @@ static inline fpu_switch_t switch_fpu_prepare(struct task_struct *old, struct ta
 
                /* Don't change CR0.TS if we just switch! */
                if (fpu.preload) {
-                       new->thread.fpu_counter++;
+                       new->thread.fpu.counter++;
                        __thread_set_has_fpu(new);
                        prefetch(new->thread.fpu.state);
                } else if (!use_eager_fpu())
                        stts();
        } else {
-               old->thread.fpu_counter = 0;
+               old->thread.fpu.counter = 0;
                task_disable_lazy_fpu_restore(old);
                if (fpu.preload) {
-                       new->thread.fpu_counter++;
+                       new->thread.fpu.counter++;
                        if (fpu_lazy_restore(new, cpu))
                                fpu.preload = 0;
                        else

diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index 2dc08c2..64d6b5d 100644 (file)
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -433,6 +433,15 @@ struct fpu {
        unsigned int last_cpu;
        unsigned int has_fpu;
        union thread_xstate *state;
+       /*
+        * This counter contains the number of consecutive context switches
+        * that the FPU is used. If this is over a threshold, the lazy fpu
+        * saving becomes unlazy to save the trap. This is an unsigned char
+        * so that after 256 times the counter wraps and the behavior turns
+        * lazy again; this to deal with bursty apps that only use FPU for
+        * a short time
+        */
+       unsigned char counter;
 };
 
 #ifdef CONFIG_X86_64
@@ -535,15 +544,6 @@ struct thread_struct {
        unsigned long           iopl;
        /* Max allowed port in the bitmap, in bytes: */
        unsigned                io_bitmap_max;
-       /*
-        * fpu_counter contains the number of consecutive context switches
-        * that the FPU is used. If this is over a threshold, the lazy fpu
-        * saving becomes unlazy to save the trap. This is an unsigned char
-        * so that after 256 times the counter wraps and the behavior turns
-        * lazy again; this to deal with bursty apps that only use FPU for
-        * a short time
-        */
-       unsigned char fpu_counter;
 };
 
 /*

diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index fd4aa56..c7793ad 100644 (file)
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -87,7 +87,7 @@ int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
 {
        *dst = *src;
 
-       dst->thread.fpu_counter = 0;
+       dst->thread.fpu.counter = 0;
        dst->thread.fpu.has_fpu = 0;
        dst->thread.fpu.state = NULL;
        task_disable_lazy_fpu_restore(dst);

diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index cf9c962..231aa57 100644 (file)
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -863,7 +863,7 @@ void math_state_restore(void)
                fpu_reset_state(tsk);
                force_sig_info(SIGSEGV, SEND_SIG_PRIV, tsk);
        } else {
-               tsk->thread.fpu_counter++;
+               tsk->thread.fpu.counter++;
        }
        kernel_fpu_enable();
 }