From: Arun chandran <arun.edarath@gmail.com>
To: kernelnewbies@kernelnewbies.org
Subject: unable to find the virtual to physical mapping
Date: Tue, 6 Dec 2022 12:13:16 +0530 [thread overview]
Message-ID: <CAL9taR12ceM=LE7U0cLNp3AuHXddW83_HcPmG1i6LgjTAe15Tg@mail.gmail.com> (raw)
Hi,
I am trying to find the virtual to physical memory mapping of a
process with kernel/linux-4.18.0-348.7.1.el8_5/tools/vm/page-types.c
a) It gives the below output for a process with pid 19721
# ./page-types -p 19721 -l | head
voffset offset len flags
400 108bf36 1 __RU_lA____M_______________________________
600 135bf80 1 ___U_l_____Ma_b____________________________
601 1258e11 1 ___U_l_____Ma_b____________________________
6aa 110075a 1 ___U_l_____Ma_b____________________________
7f335f72c 2741b88 4 __RU_lA____M_______________________________
7f335f730 20546b1 3 __RU_lA____M_______________________________
7f335f733 2741b3e 2 __RU_lA____M_______________________________
7f335f735 2741a20 1e __RU_lA____M_______________________________
7f335f753 2054690 1d __RU_lA____M_______________________________
Here the physical offsets are 28 bits. By adjusting for the 4k
pagesize I can derive a meaningful 40 bit physical address.
b) for another process it is giving
# ./page-types -p 19694 -l | head
voffset offset len flags
400 3f0366 1 __RU_lA____M_______________________________
401 19a32b 1 __RU_lA____M_______________________________
402 18d702 1 __RU_lA____M_______________________________
403 3f3fe5 1 __RU_lA____M_______________________________
404 1fbaa8 1 __RU_lA____M_______________________________
405 3f3cea 1 __RU_lA____M_______________________________
406 110455 1 __RU_lA____M_______________________________
407 30a7a8 1 __RU_lA____M_______________________________
408 2eaaee 1 __RU_lA____M_______________________________
In this, all the physical offsets are only 24 bits. Why is it like that?
The flags are not showing it as a huge page also.
RAM is mapped as
# cat /proc/iomem | grep -i ram
00001000-0009ffff : System RAM
00100000-03ffffff : System RAM
04047000-75ceffff : System RAM
76000000-9fdbb017 : System RAM
9fdbb018-9fdcc457 : System RAM
9fdcc458-9fdcd017 : System RAM
9fdcd018-9fddb857 : System RAM
9fddb858-a21f1fff : System RAM
a2245000-a2271fff : System RAM
a2273000-a66c2fff : System RAM
a99ff000-abffffff : System RAM
100000000-104fdfffff : System RAM
1050000000-204fefffff : System RAM
2050000000-304fefffff : System RAM
3050000000-404f2fffff : System RAM
4050000000-504fefffff : System RAM
5050000000-604fefffff : System RAM
6050000000-704fefffff : System RAM
7050000000-804fefffff : System RAM
How do I find out to which NUMA node's ram the physical address
"3f0366" belongs?
--Arun
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next reply other threads:[~2022-12-06 6:43 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-12-06 6:43 Arun chandran [this message]
2022-12-06 8:18 ` unable to find the virtual to physical mapping Arun chandran
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