Getting dirtied pages info

[Peter Teoh]

To elaborate further, PTE is 64-bit (for 32-bit or 64-bit OS) only
under 3 level pagetable implementation:

Look at arch/x86/include/asm/pgtable-3level_types.h:

typedef u64     pteval_t;

typedef union {
        struct {
                unsigned long pte_low, pte_high;
        };
        pteval_t pte;
} pte_t;


On Mon, Oct 3, 2011 at 12:05 PM, Peter Teoh <htmldeveloper at gmail.com> wrote:
> Basically the concept of 'dirty' is because the memory is file-backed,
> ie, everytime you changed the memory, it has to be flushed to the
> file.   In Xen the dirty bit is also used to signify the page being
> modified by the guest, and therefore certain operation like sync-ing
> between host and guest, or inter-guest sync-ing is possible.
>
> It is just a bit defined in the 64-bit PTE (defined in
> include/linux/page-flags.h), and to query it for each page in the
> system is via /proc/kpageflags, internally how that is displayed is
> implemented in fs/proc/page.c (kernel source).
>
> There is also a tool to query kpageflags:
>
> http://lwn.net/Articles/332300/
>
>
> On Fri, Sep 30, 2011 at 12:16 AM, Prateek Sharma <prateek3.14 at gmail.com> wrote:
>> Hi all,
>>     What would be a good way to get a list of all pages(lets say
>> pfns) dirtied in a particular time interval ?
>> I am reading about MMU_notifiers but i think a simpler, light-weight
>> solution might work.. I came across the page-dirtied bits...are those
>> saved somewhere by the kernel on context-switches?
>>     Thanks!
>>
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>>
>
>
>
> --
> Regards,
> Peter Teoh
>



-- 
Regards,
Peter Teoh