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Commit 616c05d110bb4ef8203f49c9d2476874077c2f6a

Authored by Vineet Gupta
Committed by Linus Torvalds
1 parent 261adc9a60
Exists in smarc-imx_3.14.28_1.0.0_ga and in 1 other branch imx_3.14.28_1.0.0_ga

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>

Showing 5 changed files with 25 additions and 5 deletions Side-by-side Diff

arch/sh/include/asm/fpu.h
Diff comments   View file @ 616c05d
... ... @@ -46,7 +46,7 @@
46 46 save_fpu(tsk);
47 47 release_fpu(regs);
48 48 } else
49   - tsk->fpu_counter = 0;
  49 + tsk->thread.fpu_counter = 0;
50 50 }
51 51  
52 52 static inline void unlazy_fpu(struct task_struct *tsk, struct pt_regs *regs)
arch/sh/include/asm/processor_32.h
Diff comments   View file @ 616c05d
... ... @@ -111,6 +111,16 @@
111 111  
112 112 /* Extended processor state */
113 113 union thread_xstate *xstate;
  114 +
  115 + /*
  116 + * fpu_counter contains the number of consecutive context switches
  117 + * that the FPU is used. If this is over a threshold, the lazy fpu
  118 + * saving becomes unlazy to save the trap. This is an unsigned char
  119 + * so that after 256 times the counter wraps and the behavior turns
  120 + * lazy again; this to deal with bursty apps that only use FPU for
  121 + * a short time
  122 + */
  123 + unsigned char fpu_counter;
114 124 };
115 125  
116 126 #define INIT_THREAD { \
arch/sh/include/asm/processor_64.h
Diff comments   View file @ 616c05d
... ... @@ -126,6 +126,16 @@
126 126  
127 127 /* floating point info */
128 128 union thread_xstate *xstate;
  129 +
  130 + /*
  131 + * fpu_counter contains the number of consecutive context switches
  132 + * that the FPU is used. If this is over a threshold, the lazy fpu
  133 + * saving becomes unlazy to save the trap. This is an unsigned char
  134 + * so that after 256 times the counter wraps and the behavior turns
  135 + * lazy again; this to deal with bursty apps that only use FPU for
  136 + * a short time
  137 + */
  138 + unsigned char fpu_counter;
129 139 };
130 140  
131 141 #define INIT_MMAP \
arch/sh/kernel/cpu/fpu.c
Diff comments   View file @ 616c05d
... ... @@ -44,7 +44,7 @@
44 44 restore_fpu(tsk);
45 45  
46 46 task_thread_info(tsk)->status |= TS_USEDFPU;
47   - tsk->fpu_counter++;
  47 + tsk->thread.fpu_counter++;
48 48 }
49 49  
50 50 void fpu_state_restore(struct pt_regs *regs)
arch/sh/kernel/process_32.c
Diff comments   View file @ 616c05d
... ... @@ -156,7 +156,7 @@
156 156 #endif
157 157 ti->addr_limit = KERNEL_DS;
158 158 ti->status &= ~TS_USEDFPU;
159   - p->fpu_counter = 0;
  159 + p->thread.fpu_counter = 0;
160 160 return 0;
161 161 }
162 162 *childregs = *current_pt_regs();
... ... @@ -189,7 +189,7 @@
189 189 unlazy_fpu(prev, task_pt_regs(prev));
190 190  
191 191 /* we're going to use this soon, after a few expensive things */
192   - if (next->fpu_counter > 5)
  192 + if (next->thread.fpu_counter > 5)
193 193 prefetch(next_t->xstate);
194 194  
195 195 #ifdef CONFIG_MMU
... ... @@ -207,7 +207,7 @@
207 207 * restore of the math state immediately to avoid the trap; the
208 208 * chances of needing FPU soon are obviously high now
209 209 */
210   - if (next->fpu_counter > 5)
  210 + if (next->thread.fpu_counter > 5)
211 211 __fpu_state_restore();
212 212  
213 213 return prev;