xref: /aosp_15_r20/external/ltp/testcases/kernel/controllers/freezer/README (revision 49cdfc7efb34551c7342be41a7384b9c40d7cab7)
1*49cdfc7eSAndroid Build Coastguard Worker==============================================================
2*49cdfc7eSAndroid Build Coastguard WorkerTest Suite for the Control Group Freezer and Signal Subsystems
3*49cdfc7eSAndroid Build Coastguard Worker==============================================================
4*49cdfc7eSAndroid Build Coastguard WorkerAuthor: Matt Helsley
5*49cdfc7eSAndroid Build Coastguard WorkerDate: June, 2008
6*49cdfc7eSAndroid Build Coastguard WorkerLast update: January 19th, 2009
7*49cdfc7eSAndroid Build Coastguard Worker
8*49cdfc7eSAndroid Build Coastguard WorkerAbout:
9*49cdfc7eSAndroid Build Coastguard Worker------
10*49cdfc7eSAndroid Build Coastguard WorkerThese tests exercise the freezer and signal subsystems (aka controllers)
11*49cdfc7eSAndroid Build Coastguard Workeravailable since kernel 2.6.28 or later.
12*49cdfc7eSAndroid Build Coastguard Worker
13*49cdfc7eSAndroid Build Coastguard WorkerThese tests exercise the freezer control group controller. This controller is
14*49cdfc7eSAndroid Build Coastguard Workera useful for implementing container checkpointing or if you wish to gradually
15*49cdfc7eSAndroid Build Coastguard Workerfreeze tasks in cgroups before doing a suspend.
16*49cdfc7eSAndroid Build Coastguard Worker
17*49cdfc7eSAndroid Build Coastguard WorkerThe common case is embodied in the freeze_thaw.sh test file. However,
18*49cdfc7eSAndroid Build Coastguard Workerthe scripts are also designed to test a few obscure cases such as:
19*49cdfc7eSAndroid Build Coastguard Worker	freeze self -- freeze the control group that the current process is
20*49cdfc7eSAndroid Build Coastguard Worker		in
21*49cdfc7eSAndroid Build Coastguard Worker	freeze cancellation -- freeze but then backout of the freeze processing
22*49cdfc7eSAndroid Build Coastguard Worker		and issue a "thaw" command before reaching the frozen state
23*49cdfc7eSAndroid Build Coastguard Worker	signalling freezing/frozen tasks -- this should delay delivery of the
24*49cdfc7eSAndroid Build Coastguard Worker		signal until the task is unfrozen
25*49cdfc7eSAndroid Build Coastguard Worker	vfork -- The vfork system call introduces an obscure special case for
26*49cdfc7eSAndroid Build Coastguard Worker		the freezer kernel code. This test case attempts to trigger any
27*49cdfc7eSAndroid Build Coastguard Worker		unanticipated corner cases involving vfork.
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30*49cdfc7eSAndroid Build Coastguard WorkerNOTES:
31*49cdfc7eSAndroid Build Coastguard Worker
32*49cdfc7eSAndroid Build Coastguard Worker	Using the cgroup freezer prevents the tasks from being automatically
33*49cdfc7eSAndroid Build Coastguard Worker		woken up upon a "Power Management Resume". You will need to
34*49cdfc7eSAndroid Build Coastguard Worker		manually unfreeze cgroups.
35*49cdfc7eSAndroid Build Coastguard Worker
36*49cdfc7eSAndroid Build Coastguard Worker	These tests assume that most of the library functions in
37*49cdfc7eSAndroid Build Coastguard Worker	libcgroup_subsys take much less than $sample_sleep time to execute. If
38*49cdfc7eSAndroid Build Coastguard Worker	this assumption is incorrect then many of these tests may fail in
39*49cdfc7eSAndroid Build Coastguard Worker	unusual ways. So make sure $sample_sleep is a "reasonable" amount of
40*49cdfc7eSAndroid Build Coastguard Worker	time.
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42*49cdfc7eSAndroid Build Coastguard WorkerBuilding:
43*49cdfc7eSAndroid Build Coastguard Worker---------
44*49cdfc7eSAndroid Build Coastguard Worker
45*49cdfc7eSAndroid Build Coastguard WorkerRun the command line:
46*49cdfc7eSAndroid Build Coastguard Worker	make all
47*49cdfc7eSAndroid Build Coastguard Worker
48*49cdfc7eSAndroid Build Coastguard Worker
49*49cdfc7eSAndroid Build Coastguard WorkerInstalling:
50*49cdfc7eSAndroid Build Coastguard Worker-----------
51*49cdfc7eSAndroid Build Coastguard Worker
52*49cdfc7eSAndroid Build Coastguard WorkerRun the command line:
53*49cdfc7eSAndroid Build Coastguard Worker
54*49cdfc7eSAndroid Build Coastguard Worker
55*49cdfc7eSAndroid Build Coastguard WorkerCleaning:
56*49cdfc7eSAndroid Build Coastguard Worker---------
57*49cdfc7eSAndroid Build Coastguard Worker
58*49cdfc7eSAndroid Build Coastguard WorkerRun the command line:
59*49cdfc7eSAndroid Build Coastguard Worker
60*49cdfc7eSAndroid Build Coastguard Worker	make clean
61*49cdfc7eSAndroid Build Coastguard Worker
62*49cdfc7eSAndroid Build Coastguard Worker
63*49cdfc7eSAndroid Build Coastguard WorkerRunning:
64*49cdfc7eSAndroid Build Coastguard Worker--------
65*49cdfc7eSAndroid Build Coastguard Worker
66*49cdfc7eSAndroid Build Coastguard WorkerRun the command line:
67*49cdfc7eSAndroid Build Coastguard Worker
68*49cdfc7eSAndroid Build Coastguard Worker	./run.sh
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70*49cdfc7eSAndroid Build Coastguard WorkerResults:
71*49cdfc7eSAndroid Build Coastguard Worker--------
72*49cdfc7eSAndroid Build Coastguard Worker
73*49cdfc7eSAndroid Build Coastguard WorkerThe results should show up as PASS/FAIL in the LTP logs for each script. The
74*49cdfc7eSAndroid Build Coastguard Workeroutput frequently will be more specific (beyond which test script failed)
75*49cdfc7eSAndroid Build Coastguard Workerabout where and what failure occurred.
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