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authorVineet Gupta <Vineet.Gupta1@synopsys.com>2013-11-12 15:08:45 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2013-11-13 12:09:13 +0900
commit616c05d110bb4ef8203f49c9d2476874077c2f6a (patch)
treeeb5bc88a430509fcdb8afe8ee9f344c903d1894d /arch/sh
parent261adc9a609dbfde815337889b9e2c8728959ab8 (diff)
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: Vineet Gupta <vgupta@synopsys.com> Cc: Paul Mundt <paul.mundt@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/sh')
-rw-r--r--arch/sh/include/asm/fpu.h2
-rw-r--r--arch/sh/include/asm/processor_32.h10
-rw-r--r--arch/sh/include/asm/processor_64.h10
-rw-r--r--arch/sh/kernel/cpu/fpu.c2
-rw-r--r--arch/sh/kernel/process_32.c6
5 files changed, 25 insertions, 5 deletions
diff --git a/arch/sh/include/asm/fpu.h b/arch/sh/include/asm/fpu.h
index 06c4281aab65..09fc2bc8a790 100644
--- a/arch/sh/include/asm/fpu.h
+++ b/arch/sh/include/asm/fpu.h
@@ -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)
diff --git a/arch/sh/include/asm/processor_32.h b/arch/sh/include/asm/processor_32.h
index e699a12cdcca..18e0377f72bb 100644
--- a/arch/sh/include/asm/processor_32.h
+++ b/arch/sh/include/asm/processor_32.h
@@ -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 { \
diff --git a/arch/sh/include/asm/processor_64.h b/arch/sh/include/asm/processor_64.h
index 1cc7d3197143..eedd4f625d07 100644
--- a/arch/sh/include/asm/processor_64.h
+++ b/arch/sh/include/asm/processor_64.h
@@ -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 \
diff --git a/arch/sh/kernel/cpu/fpu.c b/arch/sh/kernel/cpu/fpu.c
index f8f7af51c128..4e332244ea75 100644
--- a/arch/sh/kernel/cpu/fpu.c
+++ b/arch/sh/kernel/cpu/fpu.c
@@ -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)
diff --git a/arch/sh/kernel/process_32.c b/arch/sh/kernel/process_32.c
index ebd3933005b4..2885fc9d9dcd 100644
--- a/arch/sh/kernel/process_32.c
+++ b/arch/sh/kernel/process_32.c
@@ -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;