Thank you for spending your valuable time for understanding and answering my queries !!!
I was trying to apply some garbage collection algorithm on this dumped pages,thats why i want only the written pages.
Sorry to ask,but is there any other good way to find the written pages of a user process?
--
Thanks
Dhyan
On Wed, Aug 1, 2012 at 7:38 AM, bill4carson <bill4carson@xxxxxxxxx> wrote:
Yes, you can do that, only if your accounting memory doesn't get swapped
On 2012年07月31日 17:20, Dhyan wrote:
Thank You Bill !!!
I dont know my approach is correct or not,But the actual purpose was to
dump only written pages of a user process using a kernel module.I have
a kernel thread which will dump user process memory in specific
interval.So i thought of updating this flag (L_PTE_DEBUG) from
handle_pte_fault and clear from my clear thread so that i can dump only
the written pages after my last dump.
out.
If I understand correctly, when writing a page, you mark corresponding
linux pte entry with L_PTE_DEBUG. Then your kernel module periodically
loops all linux pte table, find pte entry marked with L_PTE_DEBUG.....
I don't think it's wise to do so, you have 768 1st level pgd entries
for user space, followed by 256 pte entries with each pgd entry.
it's much slower to find out the right one.
moreover, you probably need to remap those L_PTE_DEBUG physical pages
into your own current process address space. IMHO, I don't follow
such idea could be feasible.I understand how you plan to do this, could I ask why you need to dump
if you have some suggestions could you please share wth me?
the written pages?
<mailto:bill4carson@xxxxxxxxx>> wrote:arch/arm/include/asm/pgtable.__h.
On 2012年07月30日 17:39, Dhyan wrote:
Dear All,
From linux(2.6.35) arm page table architecture i can see we
have one
hardware page table and there is corresponding Linux page table
Entry
(L_PTE_*).The "Linux" PTE definitions are as like below from_________________________________________________
|#define L_PTE_PRESENT (1<< 0)
#define L_PTE_FILE (1<< 1)
#define L_PTE_YOUNG (1<< 1)
#define L_PTE_BUFFERABLE(1<< 2)
#define L_PTE_CACHEABLE (1<< 3)
#define L_PTE_USER (1<< 4)
#define L_PTE_WRITE (1<< 5)
#define L_PTE_EXEC (1<< 6)
#define L_PTE_DIRTY (1<< 7)
#define L_PTE_COHERENT (1<< 9)
#define L_PTE_SHARED (1<< 10)
|
So is it possible to add one more #|define L_PTE_DEBUG (1 <<
11)| for my
debugging purpose (basically to trap all the write to that page
and set
this bit when write happens and clear it off in another thread
)? Or
is there any limitation like we can use only L_PTE till 10th bit ?
No such limitation on bit 11, so you can use define L_PTE_DEBUG (1
<< 11)
However I don't follow why you want to do so?
So could you please help
--
Thanks & Regards
Dhayn
Kernelnewbies mailing list
Kernelnewbies@kernelnewbies.__org
<mailto:Kernelnewbies@kernelnewbies.org>
http://lists.kernelnewbies.__org/mailman/listinfo/__kernelnewbies <http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies>
--
Love each day!
--bill
--
Love each day!
--bill
_______________________________________________ Kernelnewbies mailing list Kernelnewbies@xxxxxxxxxxxxxxxxx http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
