This is changing build_zonelists for new zone.
__GFP_xxxs are flag for requires of page allocation which zone
is prefered. But, it is used as an index number for zonelists[] too.
But after my patch, __GFP_xxx might be set at same time. So,
last set bit number of __GFP is recognized for zonelists' index
by this patch.
take3->take4:
take 3's modification was still wrong.
__GFP_EASY_RECLAIM is 0x04 on i386, so fls(__GFP_EASY_RECLAIM)
is 3. zone 3 is ZONE_HIGHMEM, not ZONE_EASY_RECLAIM.
So, I rearranged __GFP_XXX flags (see: define gfp_easy_relcaim patch)
and fls() is used at highest_zone() again.
take2 -> take 3:
This patch is modified take 3 to avoid panic on i386.
__GFP_DMA32 is 0 for i386. So, ZONE_DMA32 is selected
if zone_bits is 0 which means Zone_normal.
Zone_DMA32 is not allocated on i386, so kernel paniced
by no normal memory.
In this patch, even if zone_bits is 0 adn __GFP_DMA32 is 0,
Zone_Normal is selected.
Signed-off-by: Yasunori Goto <[email protected]>
Index: zone_reclaim/mm/page_alloc.c
===================================================================
--- zone_reclaim.orig/mm/page_alloc.c 2005-12-19 20:18:29.000000000 +0900
+++ zone_reclaim/mm/page_alloc.c 2005-12-19 20:19:56.000000000 +0900
@@ -1585,14 +1585,11 @@ static int __init build_zonelists_node(p
{
struct zone *zone;
- BUG_ON(zone_type > ZONE_HIGHMEM);
+ BUG_ON(zone_type > ZONE_EASY_RECLAIM);
do {
zone = pgdat->node_zones + zone_type;
if (populated_zone(zone)) {
-#ifndef CONFIG_HIGHMEM
- BUG_ON(zone_type > ZONE_NORMAL);
-#endif
zonelist->zones[nr_zones++] = zone;
check_highest_zone(zone_type);
}
@@ -1605,12 +1602,17 @@ static int __init build_zonelists_node(p
static inline int highest_zone(int zone_bits)
{
int res = ZONE_NORMAL;
- if (zone_bits & (__force int)__GFP_HIGHMEM)
- res = ZONE_HIGHMEM;
- if (zone_bits & (__force int)__GFP_DMA32)
- res = ZONE_DMA32;
- if (zone_bits & (__force int)__GFP_DMA)
+
+ if (zone_bits == fls((__force int)__GFP_DMA))
res = ZONE_DMA;
+ if (zone_bits == fls((__force int)__GFP_DMA32) &&
+ (__force int)__GFP_DMA32 == 0x02)
+ res = ZONE_DMA32;
+ if (zone_bits == fls((__force int)__GFP_HIGHMEM))
+ res = ZONE_HIGHMEM;
+ if (zone_bits == fls((__force int)__GFP_EASY_RECLAIM))
+ res = ZONE_EASY_RECLAIM;
+
return res;
}
Index: zone_reclaim/include/linux/gfp.h
===================================================================
--- zone_reclaim.orig/include/linux/gfp.h 2005-12-19 20:19:37.000000000 +0900
+++ zone_reclaim/include/linux/gfp.h 2005-12-19 20:19:56.000000000 +0900
@@ -81,7 +81,7 @@ struct vm_area_struct;
static inline int gfp_zone(gfp_t gfp)
{
- int zone = GFP_ZONEMASK & (__force int) gfp;
+ int zone = fls(GFP_ZONEMASK & (__force int) gfp);
BUG_ON(zone >= GFP_ZONETYPES);
return zone;
}
--
Yasunori Goto
> - BUG_ON(zone_type > ZONE_HIGHMEM);
> + BUG_ON(zone_type > ZONE_EASY_RECLAIM);
It might be nice to check ifndef CONFIG_HIGHMEM that the zone isn't
particularly ZONE_HIGHMEM.
> int res = ZONE_NORMAL;
> - if (zone_bits & (__force int)__GFP_HIGHMEM)
> - res = ZONE_HIGHMEM;
> - if (zone_bits & (__force int)__GFP_DMA32)
> - res = ZONE_DMA32;
> - if (zone_bits & (__force int)__GFP_DMA)
> +
> + if (zone_bits == fls((__force int)__GFP_DMA))
> res = ZONE_DMA;
> + if (zone_bits == fls((__force int)__GFP_DMA32) &&
> + (__force int)__GFP_DMA32 == 0x02)
> + res = ZONE_DMA32;
> + if (zone_bits == fls((__force int)__GFP_HIGHMEM))
> + res = ZONE_HIGHMEM;
> + if (zone_bits == fls((__force int)__GFP_EASY_RECLAIM))
> + res = ZONE_EASY_RECLAIM;
> +
> return res;
> }
It is incredibly silly to check a constant for a value. When it is zero
instead of 2 the first part of the statement will be false anyway.
Which reminds me. Why are we using fls again? I don't see why we
aren't just (zone_bits & value) the types. It seems much easier to
understand that way.
>
> Index: zone_reclaim/include/linux/gfp.h
> ===================================================================
> --- zone_reclaim.orig/include/linux/gfp.h 2005-12-19 20:19:37.000000000 +0900
> +++ zone_reclaim/include/linux/gfp.h 2005-12-19 20:19:56.000000000 +0900
> @@ -81,7 +81,7 @@ struct vm_area_struct;
>
> static inline int gfp_zone(gfp_t gfp)
> {
> - int zone = GFP_ZONEMASK & (__force int) gfp;
> + int zone = fls(GFP_ZONEMASK & (__force int) gfp);
> BUG_ON(zone >= GFP_ZONETYPES);
> return zone;
> }
>
> > - BUG_ON(zone_type > ZONE_HIGHMEM);
> > + BUG_ON(zone_type > ZONE_EASY_RECLAIM);
>
> It might be nice to check ifndef CONFIG_HIGHMEM that the zone isn't
> particularly ZONE_HIGHMEM.
Hmm. I was a bit lazy :-(.
> > int res = ZONE_NORMAL;
> > - if (zone_bits & (__force int)__GFP_HIGHMEM)
> > - res = ZONE_HIGHMEM;
> > - if (zone_bits & (__force int)__GFP_DMA32)
> > - res = ZONE_DMA32;
> > - if (zone_bits & (__force int)__GFP_DMA)
> > +
> > + if (zone_bits == fls((__force int)__GFP_DMA))
> > res = ZONE_DMA;
> > + if (zone_bits == fls((__force int)__GFP_DMA32) &&
> > + (__force int)__GFP_DMA32 == 0x02)
> > + res = ZONE_DMA32;
> > + if (zone_bits == fls((__force int)__GFP_HIGHMEM))
> > + res = ZONE_HIGHMEM;
> > + if (zone_bits == fls((__force int)__GFP_EASY_RECLAIM))
> > + res = ZONE_EASY_RECLAIM;
> > +
> > return res;
> > }
>
> It is incredibly silly to check a constant for a value. When it is zero
> instead of 2 the first part of the statement will be false anyway.
> Which reminds me. Why are we using fls again? I don't see why we
> aren't just (zone_bits & value) the types. It seems much easier to
> understand that way.
Ahhh. I might be still confused around it. :-(
Its cause came from the value of __GFP_DMA32 which might be 0, 1, or 2.
This was that I tried to solve making zonelists for all of them.
But, something looks redundant.....
Thanks.
>
> >
> > Index: zone_reclaim/include/linux/gfp.h
> > ===================================================================
> > --- zone_reclaim.orig/include/linux/gfp.h 2005-12-19 20:19:37.000000000 +0900
> > +++ zone_reclaim/include/linux/gfp.h 2005-12-19 20:19:56.000000000 +0900
> > @@ -81,7 +81,7 @@ struct vm_area_struct;
> >
> > static inline int gfp_zone(gfp_t gfp)
> > {
> > - int zone = GFP_ZONEMASK & (__force int) gfp;
> > + int zone = fls(GFP_ZONEMASK & (__force int) gfp);
> > BUG_ON(zone >= GFP_ZONETYPES);
> > return zone;
> > }
> >
>
>
--
Yasunori Goto