Re: [patch 1/4] net: percpufy frequently used vars -- add percpu_counter_mod_bh

From: Ravikiran G Thirumalai
Date: Thu Mar 09 2006 - 03:13:01 EST


On Wed, Mar 08, 2006 at 04:32:58PM -0800, Andrew Morton wrote:
> Ravikiran G Thirumalai <kiran@xxxxxxxxxxxx> wrote:
> >
> > On Wed, Mar 08, 2006 at 03:43:21PM -0800, Andrew Morton wrote:
> > > Benjamin LaHaise <bcrl@xxxxxxxxx> wrote:
> > > >
> > > > I think it may make more sense to simply convert local_t into a long, given
> > > > that most of the users will be things like stats counters.
> > > >
> > >
> > > Yes, I agree that making local_t signed would be better. It's consistent
> > > with atomic_t, atomic64_t and atomic_long_t and it's a bit more flexible.
> > >
> > > Perhaps. A lot of applications would just be upcounters for statistics,
> > > where unsigned is desired. But I think the consistency argument wins out.
> >
> > It already is... for most of the arches except x86_64.
>
> x86 uses unsigned long.

Here's a patch making x86_64 local_t to 64 bits like other 64 bit arches.
This keeps local_t unsigned long. (We can change it to signed value
along with other arches later in one go I guess)

Thanks,
Kiran


Change x86_64 local_t to 64 bits like all other arches.

Signed-off-by: Ravikiran Thirumalai <kiran@xxxxxxxxxxxx>

Index: linux-2.6.16-rc5mm3/include/asm-x86_64/local.h
===================================================================
--- linux-2.6.16-rc5mm3.orig/include/asm-x86_64/local.h 2006-03-08 16:51:31.000000000 -0800
+++ linux-2.6.16-rc5mm3/include/asm-x86_64/local.h 2006-03-08 21:56:01.000000000 -0800
@@ -5,18 +5,18 @@

typedef struct
{
- volatile unsigned int counter;
+ volatile long counter;
} local_t;

#define LOCAL_INIT(i) { (i) }

-#define local_read(v) ((v)->counter)
+#define local_read(v) ((unsigned long)(v)->counter)
#define local_set(v,i) (((v)->counter) = (i))

static __inline__ void local_inc(local_t *v)
{
__asm__ __volatile__(
- "incl %0"
+ "incq %0"
:"=m" (v->counter)
:"m" (v->counter));
}
@@ -24,7 +24,7 @@ static __inline__ void local_inc(local_t
static __inline__ void local_dec(local_t *v)
{
__asm__ __volatile__(
- "decl %0"
+ "decq %0"
:"=m" (v->counter)
:"m" (v->counter));
}
@@ -32,7 +32,7 @@ static __inline__ void local_dec(local_t
static __inline__ void local_add(unsigned int i, local_t *v)
{
__asm__ __volatile__(
- "addl %1,%0"
+ "addq %1,%0"
:"=m" (v->counter)
:"ir" (i), "m" (v->counter));
}
@@ -40,7 +40,7 @@ static __inline__ void local_add(unsigne
static __inline__ void local_sub(unsigned int i, local_t *v)
{
__asm__ __volatile__(
- "subl %1,%0"
+ "subq %1,%0"
:"=m" (v->counter)
:"ir" (i), "m" (v->counter));
}
@@ -71,4 +71,4 @@ static __inline__ void local_sub(unsigne
#define __cpu_local_add(i, v) cpu_local_add((i), (v))
#define __cpu_local_sub(i, v) cpu_local_sub((i), (v))

-#endif /* _ARCH_I386_LOCAL_H */
+#endif /* _ARCH_X8664_LOCAL_H */
-
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