On Thu, 17 Jan 2008 18:12:48 -0600
Matt Mackall <[EMAIL PROTECTED]> wrote:
>
> > 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?
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