[RFC PATCH 0/5] mm/damon/vaddr: support {prep,apply}_probes
From: SJ Park
Date: Sat Sep 05 2026 - 16:30:26 EST
DAMON supports data attributes monitoring. However, only the physical
address space operation set (paddr) is supporting it. Add the support
to the virtual address space operation set (vaddr).
Patch 1 adds prep_probes support to vaddr. Patch 2 moves probe filter
handling code in paddr.c that can be reused by vaddr to ops-common.c.
Patch 3 adds minimum apply_probes support to vaddr. Patch 4 extends the
support for hugetlb. Patch 5 extends the support for pgidle_unset
filter.
Test
====
I confirmed it can capture ~48 mb working set of masim in vaddr mode,
like below.
First, start masim [1] to access ~48 mb memory at a time, in the
background.
$ ./masim/masim.py run \
--config_file ./masim/configs/stairs-50mb.cfg \
--repeat 10 --quiet &
Note that the config says the working set is 50mb. It is 50 million
bytes, so ~48 MiB.
Start traditional access monitoring of masim's virtual address space
using damo [2].
$ sudo ./damo/damo start $(pidof masim)
Confirm it can capture the ~48 MiB working set as the 4-th region on the
snapshot.
$ sudo ./damo/damo report access
heatmap:
11111111334[...]3000000000000000000000000000000000000000489999997777777743333333555556[...]8
# min/max temperatures: -1,150,000,000, 80,009,499, column size: 6.963
MiB
intervals: sample 5 ms aggr 100 ms (max access hz 200)
0 addr 85.355 TiB size 55.703 MiB access 0 hz age 9.500 s
1 addr 85.355 TiB size 18.984 MiB access 0 hz age 6.700 s
2 addr 127.183 TiB size 278.516 MiB access 0 hz age 11.500 s
3 addr 127.183 TiB size 7.570 MiB access 0 hz age 900 ms
4 addr 127.183 TiB size 48.133 MiB access 190 hz age 800 ms
5 addr 127.183 TiB size 54.977 MiB access 0 hz age 1.700 s
6 addr 127.183 TiB size 55.113 MiB access 0 hz age 6.700 s
7 addr 127.183 TiB size 37.902 MiB access 0 hz age 3.900 s
8 addr 127.990 TiB size 120.000 KiB access 0 hz age 11.400 s
9 addr 127.990 TiB size 8.000 KiB access 70 hz age 0 ns
10 addr 127.990 TiB size 4.000 KiB access 0 hz age 11.200 s
memory bw estimate: 8.931 GiB per second
total size: 557.027 MiB
record DAMON intervals: sample 5 ms, aggr 100 ms
Stop access monitoring and start probe-only mode access monitoring.
$ sudo ./damo/damo stop
$ sudo ./damo/damo start $(pidof masim) --probe_prep set_pgidle \
--probe_filter allow pgidle_unset --probe_weight 1
Confirm it can also capture the ~48 MiB working set as the 11-th region
on the snapshot.
$ sudo ./damo/damo report attrs
heatmap:
00000000113[...]40000000000000000000000000000000000000000000000001111114999999533333336[...]6
# min/max temperatures: -840,000,000, 330,002,000, column size: 6.961
MiB
probe prep: set_pgidle, filter: allow pgidle_unset (weight: 1)
intervals: sample 5 ms aggr 100 ms (max probe hits 20)
# size address age probe_hits
0 8.000 KiB 127.990 TiB 8.700 s 0
1 120.000 KiB 127.990 TiB 8.600 s 0
2 55.543 MiB 127.183 TiB 8.400 s 0
3 110.008 MiB 127.183 TiB 8.300 s 0
4 55.352 MiB 127.183 TiB 8.100 s 0
5 55.605 MiB 127.183 TiB 8 s 0
6 55.691 MiB 85.355 TiB 7.900 s 0
7 54.430 MiB 127.183 TiB 7.900 s 0
8 50.391 MiB 127.183 TiB 6.900 s 0
9 18.879 MiB 85.355 TiB 6 s 0
10 52.844 MiB 127.183 TiB 3.500 s 0
11 48.039 MiB 127.183 TiB 3.300 s 20
12 4.000 KiB 127.990 TiB 8.500 s 20
memory bw estimate: 0 B per second
total size: 556.910 MiB
record DAMON intervals: sample 5 ms, aggr 100 ms
[1] https://github.com/sjp38/masim
[2] https://github.com/damonitor/damo
SJ Park (5):
mm/damon/vaddr: support prep_probes
mm/damon/paddr: move probe filter handling to ops-common
mm/damon/vaddr: support apply_probe
mm/damon/vaddr: extend apply_probes() for hugetlb
mm/damon/vaddr: support pgidle_unset probe filter type
mm/damon/ops-common.c | 32 ++++++
mm/damon/ops-common.h | 2 +
mm/damon/paddr.c | 23 +----
mm/damon/vaddr.c | 232 ++++++++++++++++++++++++++++++++++++++++++
4 files changed, 267 insertions(+), 22 deletions(-)
base-commit: 59446eebc45959fe2d899aeeb301c8df6a1eaf04
--
2.47.3