lkml.org 
[lkml]   [2006]   [Aug]   [7]   [last100]   RSS Feed
Views: [more markup]  [less markup]  [headers]  [forward] 
 
Messages in this thread
/
FromAndi Kleen <>
SubjectRe: [PATCH 1/4] x86 paravirt_ops: create no_paravirt.h for native ops
DateMon, 7 Aug 2006 07:30:17 +0200
> ===================================================================
> --- /dev/null> +++ b/include/asm-i386/no_paravirt.h
I can't say I like the name. After all that should be the normal
case for a long time now ... native? normal? bareiron?

Also I would prefer if you split this file up a bit - the old
processor/system/irqflags split wasn't too bad.



> +> +/*> + * Set IOPL bits in EFLAGS from given mask> + */> +static inline void set_iopl_mask(unsigned mask)

This function can be completely written in C using local_save_flags()/local_restore_flags()
Please do that. I guess it's still a good idea to keep it separated
though because it might allow other optimizations.

e.g. i've been thinking about special casing IF changes in save/restore flags 
to optimize CPUs which have slow pushf/popf. If you already make sure
all non IF manipulations of flags are separated that would help.



> +/* Stop speculative execution */> +static inline void sync_core(void)> +{> +	unsigned int eax = 1, ebx, ecx, edx;> +	__cpuid(&eax, &ebx, &ecx, &edx);> +}

Actually I don't think this one should be para virtualized at all.
I don't see any reason at all why a hypervisor should trap it and it
is very time critical. I would recommend you move it back into the 
normal files without hooks.

> +> +/*> + * Clear and set 'TS' bit respectively> + */

The comment seems out of date (no set TS)


> +#define clts() __asm__ __volatile__ ("clts")
> +#define read_cr0() ({ \> +	unsigned int __dummy; \> +	__asm__ __volatile__( \

Maybe it's just me, but can't you just drop all these __s around
asm and volatile? They are completely useless as far I know. 

Also the assembly will be easier readable if you just keep it on a single 
line for the simple ones.

-Andi
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2006-08-07 07:33    [from the cache]
©2003-2008