tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
tools/memory-model: Document LKMM test procedure
This commit documents how to run the various scripts in order to test
a potentially pervasive change to the memory model.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
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tools/memory-model/scripts/README
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tools/memory-model/scripts/README
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README
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This file
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Testing a change to LKMM might go as follows:
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# Populate expected results without that change, and
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# runs for about an hour on an 8-CPU x86 system:
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scripts/initlitmushist.sh --timeout 10m --procs 10
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# Incorporate the change:
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git am -s -3 /path/to/patch # Or whatever it takes.
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# Test the new version of LKMM as follows...
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# Runs in seconds, good smoke test:
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scripts/checkalllitmus.sh
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# Compares results to those produced by initlitmushist.sh,
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# and runs for about an hour on an 8-CPU x86 system:
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scripts/checklitmushist.sh --timeout 10m --procs 10
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# Checks results against Result tags, runs in minutes:
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scripts/checkghlitmus.sh --timeout 10m --procs 10
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The checkghlitmus.sh should not report errors in cases where the
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checklitmushist.sh script did not also report a change. However,
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this check is nevertheless valuable because it can find errors in the
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original version of LKMM. Note however, that given the above procedure,
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an error in the original LKMM version that is fixed by the patch will
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be reported both as a mismatch by checklitmushist.sh and as an error
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by checkghlitmus.sh. One exception to this rule of thumb is when the
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test fails completely on the original version of LKMM and passes on the
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new version. In this case, checklitmushist.sh will report a mismatch
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and checkghlitmus.sh will report success. This happens when the change
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to LKMM introduces a new primitive for which litmus tests already existed.