Re: 2.6.24-rc8-mm1: powerpc oopses
From: Andrew Morton <akpm@linux-foundation.org>
Date: 2008-01-18 00:30:15
Also in:
lkml
On Thu, 17 Jan 2008 18:12:48 -0600 Matt Mackall [off-list ref] wrote:
quoted hunk ↗ jump to hunk
quoted
Do we need the ifdef? pte_offset_map/pte_unmap should be super-cheap on !CONFIG_HIGHPTE builds.In that case, pte_unmap is free, pte_offset_map is just a bit of math. So yeah, we can simplify this. How about: diff -r 5595adaea70f fs/proc/task_mmu.c--- a/fs/proc/task_mmu.c Thu Jan 17 13:26:54 2008 -0600 +++ b/fs/proc/task_mmu.c Thu Jan 17 18:11:13 2008 -0600@@ -582,20 +583,20 @@ { struct pagemapread *pm = private; pte_t *pte; - int err = 0; + int offset = 0, err = 0; - pte = pte_offset_map(pmd, addr); - for (; addr != end; pte++, addr += PAGE_SIZE) { + for (; addr != end; offset++, addr += PAGE_SIZE) { u64 pfn = PM_NOT_PRESENT; - if (is_swap_pte(*pte)) - pfn = swap_pte_to_pagemap_entry(*pte); - else if (pte_present(*pte)) - pfn = pte_pfn(*pte); + pte = pte_offset_map(pmd, addr); + if (is_swap_pte(pte[offset])) + pfn = swap_pte_to_pagemap_entry(pte[offset]); + else if (pte_present(pte[offset])) + pfn = pte_pfn(pte[offset]); + pte_unmap(pte); err = add_to_pagemap(addr, pfn, pm); if (err) return err; } - pte_unmap(pte - 1); cond_resched();
Do we need `offset' at all?
You have
static int pagemap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
void *private)
{
struct pagemapread *pm = private;
pte_t *pte;
int offset = 0, err = 0;
for (; addr != end; offset++, addr += PAGE_SIZE) {
u64 pfn = PM_NOT_PRESENT;
pte = pte_offset_map(pmd, addr);
if (is_swap_pte(pte[offset]))
pfn = swap_pte_to_pagemap_entry(pte[offset]);
else if (pte_present(pte[offset]))
pfn = pte_pfn(pte[offset]);
pte_unmap(pte);
err = add_to_pagemap(addr, pfn, pm);
if (err)
return err;
}
cond_resched();
return err;
}
but I think we just do s/pte[offset]/*pte/. The virtual address should be
the only thing we need to increment as we walk across the addresses here?