diff options
| author | Linus Torvalds <torvalds@linux-foundation.org> | 2012-02-21 19:25:45 +0100 |
|---|---|---|
| committer | H. Peter Anvin <hpa@linux.intel.com> | 2012-02-21 23:12:46 +0100 |
| commit | 8546c008924d5fd1724fa698eaa92b414bafd50d (patch) | |
| tree | fe2d3f50b350c884201c57ca6c331dd867c5d1e8 /arch/x86/kernel/cpu/common.c | |
| parent | i387: export 'fpu_owner_task' per-cpu variable (diff) | |
| download | linux-8546c008924d5fd1724fa698eaa92b414bafd50d.tar.xz linux-8546c008924d5fd1724fa698eaa92b414bafd50d.zip | |
i387: Uninline the generic FP helpers that we expose to kernel modules
Instead of exporting the very low-level internals of the FPU state
save/restore code (ie things like 'fpu_owner_task'), we should export
the higher-level interfaces.
Inlining these things is pointless anyway: sure, sometimes the end
result is small, but while 'stts()' can result in just three x86
instructions, those are not cheap instructions (writing %cr0 is a
serializing instruction and a very slow one at that).
So the overhead of a function call is not noticeable, and we really
don't want random modules mucking about with our internal state save
logic anyway.
So this unexports 'fpu_owner_task', and instead uninlines and exports
the actual functions that modules can use: fpu_kernel_begin/end() and
unlazy_fpu().
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/alpine.LFD.2.02.1202211339590.5354@i5.linux-foundation.org
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Diffstat (limited to 'arch/x86/kernel/cpu/common.c')
| -rw-r--r-- | arch/x86/kernel/cpu/common.c | 2 |
1 files changed, 0 insertions, 2 deletions
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index c0f7d68d318f..cb71b01ab66e 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -1045,7 +1045,6 @@ DEFINE_PER_CPU(char *, irq_stack_ptr) = DEFINE_PER_CPU(unsigned int, irq_count) = -1; DEFINE_PER_CPU(struct task_struct *, fpu_owner_task); -EXPORT_PER_CPU_SYMBOL(fpu_owner_task); /* * Special IST stacks which the CPU switches to when it calls @@ -1115,7 +1114,6 @@ void debug_stack_reset(void) DEFINE_PER_CPU(struct task_struct *, current_task) = &init_task; EXPORT_PER_CPU_SYMBOL(current_task); DEFINE_PER_CPU(struct task_struct *, fpu_owner_task); -EXPORT_PER_CPU_SYMBOL(fpu_owner_task); #ifdef CONFIG_CC_STACKPROTECTOR DEFINE_PER_CPU_ALIGNED(struct stack_canary, stack_canary); |