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| author | Vineet Gupta <Vineet.Gupta1@synopsys.com> | 2013-11-12 15:08:46 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-11-13 12:09:13 +0900 |
| commit | c375f15a434db1867cb004bafba92aba739e4e39 (patch) | |
| tree | 419ff5ddf823f9b43d95d1fc6345611989364cde /arch/x86/include/asm/processor.h | |
| parent | 616c05d110bb4ef8203f49c9d2476874077c2f6a (diff) | |
| download | lwn-c375f15a434db1867cb004bafba92aba739e4e39.tar.gz lwn-c375f15a434db1867cb004bafba92aba739e4e39.zip | |
x86: 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 i386_defconfig + gcc 4.7.3
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Paul Mundt <paul.mundt@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/x86/include/asm/processor.h')
| -rw-r--r-- | arch/x86/include/asm/processor.h | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h index 987c75ecc334..7b034a4057f9 100644 --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -488,6 +488,15 @@ 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; }; /* |