linux-next.git/tools/testing/selftests/kvm/lib/perf_test_util.c, branch master

KVM: selftests: Rename perf_test_util.[ch] to memstress.[ch]

2022-11-16T18:57:34+00:00

Rename the perf_test_util.[ch] files to memstress.[ch]. Symbols are renamed in the following commit to reduce the amount of churn here in hopes of playiing nice with git's file rename detection. The name "memstress" was chosen to better describe the functionality proveded by this library, which is to create and run a VM that reads/writes to guest memory on all vCPUs in parallel. "memstress" also contains the same number of chracters as "perf_test", making it a drop-in replacement in symbols, e.g. function names, without impacting line lengths. Also the lack of underscore between "mem" and "stress" makes it clear "memstress" is a noun. Signed-off-by: David Matlack Reviewed-by: Sean Christopherson Link: https://lore.kernel.org/r/20221012165729.3505266-2-dmatlack@google.com Signed-off-by: Sean Christopherson

KVM: selftests: randomize page access order

2022-11-16T18:57:22+00:00

Create the ability to randomize page access order with the -a argument. This includes the possibility that the same pages may be hit multiple times during an iteration or not at all. Population has random access as false to ensure all pages will be touched by population and avoid page faults in late dirty memory that would pollute the test results. Signed-off-by: Colton Lewis Reviewed-by: David Matlack Link: https://lore.kernel.org/r/20221107182208.479157-5-coltonlewis@google.com Signed-off-by: Sean Christopherson

KVM: selftests: randomize which pages are written vs read

2022-11-16T18:57:19+00:00

Randomize which pages are written vs read using the random number generator. Change the variable wr_fract and associated function calls to write_percent that now operates as a percentage from 0 to 100 where X means each page has an X% chance of being written. Change the -f argument to -w to reflect the new variable semantics. Keep the same default of 100% writes. Population always uses 100% writes to ensure all memory is actually populated and not just mapped to the zero page. The prevents expensive copy-on-write faults from occurring during the dirty memory iterations below, which would pollute the performance results. Each vCPU calculates its own random seed by adding its index to the seed provided. Signed-off-by: Colton Lewis Reviewed-by: David Matlack Link: https://lore.kernel.org/r/20221107182208.479157-4-coltonlewis@google.com Signed-off-by: Sean Christopherson

KVM: selftests: create -r argument to specify random seed

2022-11-16T18:17:31+00:00

Create a -r argument to specify a random seed. If no argument is provided, the seed defaults to 1. The random seed is set with perf_test_set_random_seed() and must be set before guest_code runs to apply. Signed-off-by: Colton Lewis Reviewed-by: David Matlack Link: https://lore.kernel.org/r/20221107182208.479157-3-coltonlewis@google.com Signed-off-by: Sean Christopherson

KVM: selftests: Allowing running dirty_log_perf_test on specific CPUs

2022-11-16T18:03:24+00:00

Add a command line option, -c, to pin vCPUs to physical CPUs (pCPUs), i.e. to force vCPUs to run on specific pCPUs. Requirement to implement this feature came in discussion on the patch "Make page tables for eager page splitting NUMA aware" https://lore.kernel.org/lkml/YuhPT2drgqL+osLl@google.com/ This feature is useful as it provides a way to analyze performance based on the vCPUs and dirty log worker locations, like on the different NUMA nodes or on the same NUMA nodes. To keep things simple, implementation is intentionally very limited, either all of the vCPUs will be pinned followed by an optional main thread or nothing will be pinned. Signed-off-by: Vipin Sharma Suggested-by: David Matlack Reviewed-by: Sean Christopherson Link: https://lore.kernel.org/r/20221103191719.1559407-8-vipinsh@google.com Signed-off-by: Sean Christopherson

KVM: selftests: Drop @num_percpu_pages from __vm_create_with_vcpus()

2022-06-11T15:47:25+00:00

Drop @num_percpu_pages from __vm_create_with_vcpus(), all callers pass '0' and there's unlikely to be a test that allocates just enough memory that it needs a per-CPU allocation, but not so much that it won't just do its own memory management. Signed-off-by: Sean Christopherson Signed-off-by: Paolo Bonzini

KVM: selftests: Drop @slot0_mem_pages from __vm_create_with_vcpus()

2022-06-11T15:47:25+00:00

All callers of __vm_create_with_vcpus() pass DEFAULT_GUEST_PHY_PAGES for @slot_mem_pages; drop the param and just hardcode the "default" as the base number of pages for slot0. Signed-off-by: Sean Christopherson Signed-off-by: Paolo Bonzini

KVM: selftests: Open code and drop 'struct kvm_vm' accessors

2022-06-11T15:47:24+00:00

Drop a variety of 'struct kvm_vm' accessors that wrap a single variable now that tests can simply reference the variable directly. Signed-off-by: Sean Christopherson Signed-off-by: Paolo Bonzini

KVM: selftests: Purge vm+vcpu_id == vcpu silliness

2022-06-11T15:47:22+00:00

Take a vCPU directly instead of a VM+vcpu pair in all vCPU-scoped helpers and ioctls. Signed-off-by: Sean Christopherson Signed-off-by: Paolo Bonzini

KVM: selftests: Stop conflating vCPU index and ID in perf tests

2022-06-11T15:47:20+00:00

Track vCPUs by their 'struct kvm_vcpu' object, and stop assuming that a vCPU's ID is the same as its index when referencing a vCPU's metadata. Signed-off-by: Sean Christopherson Signed-off-by: Paolo Bonzini