Commit 616c05d1 authored by Vineet Gupta's avatar Vineet Gupta Committed by Linus Torvalds
Browse files

sh: move fpu_counter into ARCH specific thread_struct 



Only a couple of arches (sh/x86) use fpu_counter in task_struct so it can
be moved out into ARCH specific thread_struct, reducing the size of
task_struct for other arches.

Compile tested sh defconfig + sh4-linux-gcc (4.6.3)

Signed-off-by: default avatarVineet Gupta <vgupta@synopsys.com>
Cc: Paul Mundt <paul.mundt@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 261adc9a

arch/sh/include/asm/fpu.h

+1 −1
Original line number Diff line number Diff line
@@ -46,7 +46,7 @@ static inline void __unlazy_fpu(struct task_struct *tsk, struct pt_regs *regs) 
		save_fpu(tsk);

		release_fpu(regs);

	} else

		tsk->fpu_counter = 0;

		tsk->thread.fpu_counter = 0;

}



static inline void unlazy_fpu(struct task_struct *tsk, struct pt_regs *regs)

arch/sh/include/asm/processor_32.h

+10 −0
Original line number Diff line number Diff line
@@ -111,6 +111,16 @@ struct thread_struct { 


	/* Extended processor state */

	union thread_xstate *xstate;



	/*

	 * 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;

};



#define INIT_THREAD  {						\

arch/sh/include/asm/processor_64.h

+10 −0
Original line number Diff line number Diff line
@@ -126,6 +126,16 @@ struct thread_struct { 


	/* floating point info */

	union thread_xstate *xstate;



	/*

	 * 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;

};



#define INIT_MMAP \

arch/sh/kernel/cpu/fpu.c

+1 −1
Original line number Diff line number Diff line
@@ -44,7 +44,7 @@ void __fpu_state_restore(void) 
	restore_fpu(tsk);



	task_thread_info(tsk)->status |= TS_USEDFPU;

	tsk->fpu_counter++;

	tsk->thread.fpu_counter++;

}



void fpu_state_restore(struct pt_regs *regs)

arch/sh/kernel/process_32.c

+3 −3
Original line number Diff line number Diff line
@@ -156,7 +156,7 @@ int copy_thread(unsigned long clone_flags, unsigned long usp, 
#endif

		ti->addr_limit = KERNEL_DS;

		ti->status &= ~TS_USEDFPU;

		p->fpu_counter = 0;

		p->thread.fpu_counter = 0;

		return 0;

	}

	*childregs = *current_pt_regs();
@@ -189,7 +189,7 @@ __switch_to(struct task_struct *prev, struct task_struct *next) 
	unlazy_fpu(prev, task_pt_regs(prev));



	/* we're going to use this soon, after a few expensive things */

	if (next->fpu_counter > 5)

	if (next->thread.fpu_counter > 5)

		prefetch(next_t->xstate);



#ifdef CONFIG_MMU
@@ -207,7 +207,7 @@ __switch_to(struct task_struct *prev, struct task_struct *next) 
	 * restore of the math state immediately to avoid the trap; the

	 * chances of needing FPU soon are obviously high now

	 */

	if (next->fpu_counter > 5)

	if (next->thread.fpu_counter > 5)

		__fpu_state_restore();



	return prev;

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