Hello,
Russell King wrote:
> On Mon, Feb 25, 2008 at 02:26:48PM +0100, Uwe Kleine-König wrote:
> > Hello,
> >
> > I see the following:
> >
> > / # for i in 1 2 3; do grep PageTables /proc/meminfo; done
> > PageTables: 4 kB
> > PageTables: 4294967292 kB
> > PageTables: 4294967284 kB
> >
> > and I bisected it down to 2f569af (CONFIG_HIGHPTE vs. sub-page page
> > tables.) This still happens in 2.6.25-rc3.
> >
> > I have not investigated further, so I cannot tell if it's only the
> > output in meminfo that is broken.
> >
> > This is on ARCH=arm, on a Digi cc9p9360 with ns9xxx_defconfig.
>
> Note that there's been other reports of this on other ARM platforms as
> well.
I didn't see these. @Russell: can you point me to these reports?
With the patch below, I get two times printascii('-'), zero times
printascii('+') and the following two stacktraces:
[<c0120330>] (dump_stack+0x0/0x14) from [<c01232ec>] (free_pgd_slow+0xa4/0x10c)
[<c0123248>] (free_pgd_slow+0x0/0x10c) from [<c01318d8>] (__mmdrop+0x24/0x54)
r7:c1c88000 r6:c14d8cc0 r5:c1c4cc40 r4:c14d8cc0
[<c01318b4>] (__mmdrop+0x0/0x54) from [<c01319b4>] (mmput+0xac/0xc4)
r4:c14d8cc0
[<c0131908>] (mmput+0x0/0xc4) from [<c018318c>] (flush_old_exec+0x320/0x680)
r4:c14d8b60
[<c0182e6c>] (flush_old_exec+0x0/0x680) from [<c01b0460>] (load_elf_binary+0x3d4/0x15d0)
[<c01b008c>] (load_elf_binary+0x0/0x15d0) from [<c0183af4>] (search_binary_handler+0xa4/0x1fc)
[<c0183a50>] (search_binary_handler+0x0/0x1fc) from [<c0183db0>] (do_execve+0x164/0x188)
[<c0183c4c>] (do_execve+0x0/0x188) from [<c011fb94>] (sys_execve+0x3c/0x5c)
r8:c011cb44 r7:c1c24000 r6:c1c89fb0 r5:0008cba8 r4:c1c24000
[<c011fb58>] (sys_execve+0x0/0x5c) from [<c011c9a0>] (ret_fast_syscall+0x0/0x2c)
r7:0000000b r6:00000001 r5:0008cb88 r4:0008cba0
[<c0120330>] (dump_stack+0x0/0x14) from [<c01232ec>] (free_pgd_slow+0xa4/0x10c)
[<c0123248>] (free_pgd_slow+0x0/0x10c) from [<c01318d8>] (__mmdrop+0x24/0x54)
r7:c1c4cc40 r6:c14d8e20 r5:00000040 r4:c14d8b60
[<c01318b4>] (__mmdrop+0x0/0x54) from [<c012d204>] (finish_task_switch+0x8c/0x90)
r4:c1c4cc40
[<c012d178>] (finish_task_switch+0x0/0x90) from [<c0215614>] (schedule+0x1c0/0x2b0)
r5:c1c13bc0 r4:c14d8b60
[<c0215454>] (schedule+0x0/0x2b0) from [<c01363d4>] (do_wait+0x278/0xbb0)
[<c013615c>] (do_wait+0x0/0xbb0) from [<c0136da4>] (sys_wait4+0x98/0xd4)
[<c0136d0c>] (sys_wait4+0x0/0xd4) from [<c011c9a0>] (ret_fast_syscall+0x0/0x2c)
r8:c011cb44 r7:00000072 r6:00075989 r5:00000000 r4:00090288
when executing /bin/true. I assume these are the two entries that go
missing? Maybe this helps someone with a deeper understanding?
IMHO the last hunk is worth to make it into mainstream.
Best regards
Uwe
diff --git a/include/asm-arm/pgalloc.h b/include/asm-arm/pgalloc.h
index 163b030..0c85d94 100644
--- a/include/asm-arm/pgalloc.h
+++ b/include/asm-arm/pgalloc.h
@@ -75,7 +75,7 @@ pte_alloc_one(struct mm_struct *mm, unsigned long addr)
if (pte) {
void *page = page_address(pte);
clean_dcache_area(page, sizeof(pte_t) * PTRS_PER_PTE);
- pgtable_page_ctor(pte);
+ //pgtable_page_ctor(pte);
}
return pte;
@@ -94,7 +94,7 @@ static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
static inline void pte_free(struct mm_struct *mm, pgtable_t pte)
{
- pgtable_page_dtor(pte);
+ //pgtable_page_dtor(pte);
__free_page(pte);
}
diff --git a/include/linux/vmstat.h b/include/linux/vmstat.h
index 75370ec..5553d3f 100644
--- a/include/linux/vmstat.h
+++ b/include/linux/vmstat.h
@@ -225,8 +225,13 @@ static inline void __mod_zone_page_state(struct zone *zone,
zone_page_state_add(delta, zone, item);
}
+void printch(char);
static inline void __inc_zone_state(struct zone *zone, enum zone_stat_item item)
{
+ if (item == NR_PAGETABLE) {
+ printch('+');
+ }
+
atomic_long_inc(&zone->vm_stat[item]);
atomic_long_inc(&vm_stat[item]);
}
@@ -239,6 +244,11 @@ static inline void __inc_zone_page_state(struct page *page,
static inline void __dec_zone_state(struct zone *zone, enum zone_stat_item item)
{
+ if (item == NR_PAGETABLE) {
+ printch('-');
+ dump_stack();
+ }
+
atomic_long_dec(&zone->vm_stat[item]);
atomic_long_dec(&vm_stat[item]);
}
@@ -246,8 +256,7 @@ static inline void __dec_zone_state(struct zone *zone, enum zone_stat_item item)
static inline void __dec_zone_page_state(struct page *page,
enum zone_stat_item item)
{
- atomic_long_dec(&page_zone(page)->vm_stat[item]);
- atomic_long_dec(&vm_stat[item]);
+ __dec_zone_state(page_zone(page), item);
}
/*
--
Uwe Kleine-König, Software Engineer
Digi International GmbH Branch Breisach, Küferstrasse 8, 79206 Breisach, Germany
Tax: 315/5781/0242 / VAT: DE153662976 / Reg. Amtsgericht Dortmund HRB 13962
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