On Fri, 29 Dec 2006 10:34:21 +1100 Rusty Russell <rusty@rustcorp.com.au> wrote:> This make sure it's paravirtualized correctly when CONFIG_PARAVIRT=y. > > Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> > > diff -r 4ff048622391 drivers/md/raid6x86.h > --- a/drivers/md/raid6x86.h Thu Dec 28 16:52:54 2006 +1100 > +++ b/drivers/md/raid6x86.h Fri Dec 29 10:09:38 2006 +1100 > @@ -75,13 +75,14 @@ static inline unsigned long raid6_get_fp > unsigned long cr0; > > preempt_disable(); > - asm volatile("mov %%cr0,%0 ; clts" : "=r" (cr0)); > + cr0 = read_cr0(); > + clts(); > return cr0; > } > > static inline void raid6_put_fpu(unsigned long cr0) > { > - asm volatile("mov %0,%%cr0" : : "r" (cr0)); > + write_cr0(cr0); > preempt_enable(); > } >Perhaps we also need: --- a/drivers/md/raid6x86.h~use-correct-macros-in-raid-code-not-raw-asm-include +++ a/drivers/md/raid6x86.h @@ -21,6 +21,8 @@ #if defined(__i386__) || defined(__x86_64__) +#include <asm/system.h> + #ifdef __x86_64__ typedef struct { _ ?
This make sure it's paravirtualized correctly when CONFIG_PARAVIRT=y.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
diff -r 4ff048622391 drivers/md/raid6x86.h
--- a/drivers/md/raid6x86.h Thu Dec 28 16:52:54 2006 +1100
+++ b/drivers/md/raid6x86.h Fri Dec 29 10:09:38 2006 +1100
@@ -75,13 +75,14 @@ static inline unsigned long raid6_get_fp
unsigned long cr0;
preempt_disable();
- asm volatile("mov %%cr0,%0 ; clts" : "=r" (cr0));
+ cr0 = read_cr0();
+ clts();
return cr0;
}
static inline void raid6_put_fpu(unsigned long cr0)
{
- asm volatile("mov %0,%%cr0" : : "r" (cr0));
+ write_cr0(cr0);
preempt_enable();
}
On Fri, 29 Dec 2006, Rusty Russell wrote:> > This make sure it's paravirtualized correctly when CONFIG_PARAVIRT=y.Why doesn't this code use "kernel_fpu_begin()" and "kernel_fpu_end()"? The raid6 code is crap, and slower. It does "fsave/frstor" or movaps or other crud, and the thing is, it shouldn't. It should just do kernel_fpu_begin/end(), which does it all right, and avoids saving any state at all unless it's being used by the user RIGHT NOW. Linus