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dmatest: replace stored results mechanism, with uniform messages
For long running tests the tracking results in a memory leak for the "ok" results, and for the failures the kernel log should be sufficient. Provide a uniform format for error messages so they can be easily parsed and remove the debugfs file. Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
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‎Documentation/dmatest.txt

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@@ -16,9 +16,8 @@ be built as module or inside kernel. Let's consider those cases.
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Part 2 - When dmatest is built as a module...
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After mounting debugfs and loading the module, the /sys/kernel/debug/dmatest
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folder with nodes will be created. There are two important files located. First
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is the 'run' node that controls run and stop phases of the test, and the second
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one, 'results', is used to get the test case results.
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folder with a file named 'run' nodes will be created. 'run' controls run and
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stop phases of the test.
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Note that in this case test will not run on load automatically.
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@@ -32,8 +31,9 @@ Hint: available channel list could be extracted by running the following
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command:
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% ls -1 /sys/class/dma/
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After a while you will start to get messages about current status or error like
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in the original code.
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Once started a message like "dmatest: Started 1 threads using dma0chan0" is
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emitted. After that only test failure messages are reported until the test
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stops.
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Note that running a new test will not stop any in progress test.
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@@ -62,19 +62,18 @@ case. You always could check them at run-time by running
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Part 4 - Gathering the test results
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The module provides a storage for the test results in the memory. The gathered
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data could be used after test is done.
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Test results are printed to the kernel log buffer with the format:
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The special file 'results' in the debugfs represents gathered data of the in
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progress test. The messages collected are printed to the kernel log as well.
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"dmatest: result <channel>: <test id>: '<error msg>' with src_off=<val> dst_off=<val> len=<val> (<err code>)"
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Example of output:
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% cat /sys/kernel/debug/dmatest/results
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dma0chan0-copy0: #1: No errors with src_off=0x7bf dst_off=0x8ad len=0x3fea (0)
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% dmesg | tail -n 1
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dmatest: result dma0chan0-copy0: #1: No errors with src_off=0x7bf dst_off=0x8ad len=0x3fea (0)
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The message format is unified across the different types of errors. A number in
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the parens represents additional information, e.g. error code, error counter,
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or status.
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or status. A test thread also emits a summary line at completion listing the
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number of tests executed, number that failed, and a result code.
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Note that the buffer comparison is done in the old way, i.e. data is not
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collected and just printed out.
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The details of a data miscompare error are also emitted, but do not follow the
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above format.

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