[RFC PATCH 1/5] selftests/damon: add a DAMON interface wrapper python module

[SeongJae Park <sj@kernel.org>]

DAMON sysfs interface supports almost every DAMON functionality.  For
that, it provides a number of files and hierarchies that not simple to
be manually manipulated, or writing shell script every time.  For the
reason, DAMON is not having good functionality selftests.  Adding an
existing DAMON user space tool and using it could also be a way, but it
would add unnecessarily huge change that not essential for the test
purpose.  Write a minimum python module that can further extended to be
used as an easy-to-use DAMON functionality test purpose DAMON user
interface wrapper.

Note that this commit is implementing only basic data structures for
representing the sysfs files.  More operations will be implemented by
following commits, as needed for specific real test cases.

Signed-off-by: SeongJae Park <sj@kernel.org>
---
 tools/testing/selftests/damon/_damon.py | 102 ++++++++++++++++++++++++
 1 file changed, 102 insertions(+)
 create mode 100644 tools/testing/selftests/damon/_damon.py

diff --git a/tools/testing/selftests/damon/_damon.py b/tools/testing/selftests/damon/_damon.py
new file mode 100644
index 000000000000..78101846ab66
--- /dev/null
+++ b/tools/testing/selftests/damon/_damon.py
@@ -0,0 +1,102 @@
+# SPDX-License-Identifier: GPL-2.0
+
+class DamosAccessPattern:
+    size = None
+    nr_accesses = None
+    age = None
+    scheme = None
+
+    def __init__(self, size=None, nr_accesses=None, age=None):
+        self.size = size
+        self.nr_accesses = nr_accesses
+        self.age = age
+
+        if self.size == None:
+            self.size = [0, 2**64 - 1]
+        if self.nr_accesses == None:
+            self.nr_accesses = [0, 2**64 - 1]
+        if self.age == None:
+            self.age = [0, 2**64 - 1]
+
+class Damos:
+    action = None
+    access_pattern = None
+    # todo: Support quotas, watermarks, stats, tried_regions
+    idx = None
+    context = None
+
+    def __init__(self, action='stat', access_pattern=DamosAccessPattern()):
+        self.action = action
+        self.access_pattern = access_pattern
+        self.access_pattern.scheme = self
+
+class DamonTarget:
+    pid = None
+    # todo: Support target regions if test is made
+    idx = None
+    context = None
+
+    def __init__(self, pid):
+        self.pid = pid
+
+class DamonAttrs:
+    sample_us = None
+    aggr_us = None
+    update_us = None
+    min_nr_regions = None
+    max_nr_regions = None
+    context = None
+
+    def __init__(self, sample_us=5000, aggr_us=100000, update_us=1000000,
+            min_nr_regions=10, max_nr_regions=1000):
+        self.sample_us = sample_us
+        self.aggr_us = aggr_us
+        self.update_us = update_us
+        self.min_nr_regions = min_nr_regions
+        self.max_nr_regions = max_nr_regions
+
+class DamonCtx:
+    ops = None
+    monitoring_attrs = None
+    targets = None
+    schemes = None
+    kdamond = None
+    idx = None
+
+    def __init__(self, ops='paddr', monitoring_attrs=DamonAttrs(), targets=[],
+            schemes=[]):
+        self.ops = ops
+        self.monitoring_attrs = monitoring_attrs
+        self.monitoring_attrs.context = self
+
+        self.targets = targets
+        for idx, target in enumerate(self.targets):
+            target.idx = idx
+            target.context = self
+
+        self.schemes = schemes
+        for idx, scheme in enumerate(self.schemes):
+            scheme.idx = idx
+            scheme.context = self
+
+class Kdamond:
+    state = None
+    pid = None
+    contexts = None
+    idx = None      # index of this kdamond between siblings
+    kdamonds = None # parent
+
+    def __init__(self, contexts=[]):
+        self.contexts = contexts
+        for idx, context in enumerate(self.contexts):
+            context.idx = idx
+            context.kdamond = self
+
+class Kdamonds:
+    kdamonds = []
+
+    def __init__(self, kdamonds=[]):
+        self.kdamonds = kdamonds
+        for idx, kdamond in enumerate(self.kdamonds):
+            kdamond.idx = idx
+            kdamond.kdamonds = self
-- 
2.34.1