This series contains a few cleanups that didn't make it into previous series, including some cosmetic changes and small bug fixes. The series also lays the groundwork for a memslot modification test which stresses the memslot update and page fault code paths in an attempt to expose races.
Tested: dirty_log_perf_test, memslot_modification_stress_test, and demand_paging_test were run, with all the patches in this series applied, on an Intel Skylake machine.
echo Y > /sys/module/kvm/parameters/tdp_mmu; \ ./memslot_modification_stress_test -i 1000 -v 64 -b 1G; \ ./memslot_modification_stress_test -i 1000 -v 64 -b 64M -o; \ ./dirty_log_perf_test -v 64 -b 1G; \ ./dirty_log_perf_test -v 64 -b 64M -o; \ ./demand_paging_test -v 64 -b 1G; \ ./demand_paging_test -v 64 -b 64M -o; \ echo N > /sys/module/kvm/parameters/tdp_mmu; \ ./memslot_modification_stress_test -i 1000 -v 64 -b 1G; \ ./memslot_modification_stress_test -i 1000 -v 64 -b 64M -o; \ ./dirty_log_perf_test -v 64 -b 1G; \ ./dirty_log_perf_test -v 64 -b 64M -o; \ ./demand_paging_test -v 64 -b 1G; \ ./demand_paging_test -v 64 -b 64M -o
The tests behaved as expected, and fixed the problem of the population stage being skipped in dirty_log_perf_test. This can be seen in the output, with the population stage taking about the time dirty pass 1 took and dirty pass 1 falling closer to the times for the other passes.
Note that when running these tests, the -o option causes the test to take much longer as the work each vCPU must do increases proportional to the number of vCPUs.
You can view this series in Gerrit at: https://linux-review.googlesource.com/c/linux/kernel/git/torvalds/linux/+/72...
Ben Gardon (6): KVM: selftests: Rename timespec_diff_now to timespec_elapsed KVM: selftests: Avoid flooding debug log while populating memory KVM: selftests: Convert iterations to int in dirty_log_perf_test KVM: selftests: Fix population stage in dirty_log_perf_test KVM: selftests: Add option to overlap vCPU memory access KVM: selftests: Add memslot modification stress test
tools/testing/selftests/kvm/.gitignore | 1 + tools/testing/selftests/kvm/Makefile | 1 + .../selftests/kvm/demand_paging_test.c | 40 +++- .../selftests/kvm/dirty_log_perf_test.c | 72 +++--- .../selftests/kvm/include/perf_test_util.h | 4 +- .../testing/selftests/kvm/include/test_util.h | 2 +- .../selftests/kvm/lib/perf_test_util.c | 25 ++- tools/testing/selftests/kvm/lib/test_util.c | 2 +- .../kvm/memslot_modification_stress_test.c | 211 ++++++++++++++++++ 9 files changed, 307 insertions(+), 51 deletions(-) create mode 100644 tools/testing/selftests/kvm/memslot_modification_stress_test.c