C H A P T E R  19

Level 2 Cache Test (l2sramtest)

l2sramtest exercises the level2 cache in the CPU module of Sun systems. In most CPUs, the level2 cache is also the external cache, but in some cases the level2 cache is on the chip. This test writes, reads, and verifies access of multiple virtual addresses. This test contains multiple subtests that try to exercise the l2cache by causing hits/misses, performing marching patterns on the l2cache cells, and writing patterns that cause electrical stress.

l2sramtest is self scaling and adaptive. It scales with the size of the system. It will automatically retrieve the number of CPUs in the system and internally create that many threads of l2sramtest to give coverage to the whole system at a given time. This test also dynamically determines the size and organization of the l2cache. The user does not have to input these values.

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l2sramtest Options

To reach the dialog box below, right-click on the test name in the System Map and select Test Parameter Options. If you do not see this test in the System Map, you might need to expand the collapsed groups, or your system may not include the device appropriate to this test. Refer to the SunVTS User's Guide for more details.

FIGURE 19-1 l2sramtest Test Parameter Options Dialog Box

TABLE 19-1 l2sramtest Options

Option	Description
Thrash Cycles	Specifies the number of thrashing cycles the test completes for the level2 cache on the system. The default value is 8.
ECC Error Monitor	Specifies whether the error monitoring should be on or off. The error monitor monitors the /var/adm/messages file for failure messages which could be caused due to the test. The default value is OFF.
Threshold	Specifies the threshold value of the number of errors after which the test would register an error. This argument is only applicable if the Error Monitor option is ON. The errors that come on the /var/adm/messages could be correctable error, that is why the threshold value is provided for the user to give a facility to ignore the errors if they are below the threshold value. The default value is 1.

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Note - The l2sramtest automatically handles processor binding. Users are advised to not use the Processor Affinity option for the l2sramtest.

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l2sramtest Test Modes

TABLE 19-2 l2sramtest Supported Test Modes

Test Mode	Description
Exclusive	Performs only the l2sramtest (full test).

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l2sramtest Command-Line Syntax

/opt/SUNWvts/bin/sparcv9/l2sramtest -standard_arguments -o [dev=l2sram, count=[1...1023], em=[Enabled,Disabled], threshold=[0..255]]

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Note - The l2sramtest is not a per CPU test. There will be only one l2sramtest for the whole system (one image of Solaris). It will run on all the CPUs of the domain.

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TABLE 19-3 l2sramtest Command-Line Syntax

Argument	Description
dev=l2sram	Specifies the device. The default value is l2sram.
count=number	Specifies the number of thrashing cycles that the test completes for the level2 cache on the system. Default value for Offline mode is 8.
em=Enabled/Disabled	Specifies the enabling or disabling of the ECC Error Monitor. The default value is Disabled.
threshold=number	Specifies the threshold value of how many correctable ECC errors can occur in the elapsed time before l2sramtest reports a test failure. The default value is 1.

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