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2024-11-04selftests/resctrl: Do not compare performance counters and resctrl at low ↵Reinette Chatre
bandwidth The MBA test incrementally throttles memory bandwidth, each time followed by a comparison between the memory bandwidth observed by the performance counters and resctrl respectively. While a comparison between performance counters and resctrl is generally appropriate, they do not have an identical view of memory bandwidth. For example RAS features or memory performance features that generate memory traffic may drive accesses that are counted differently by performance counters and MBM respectively, for instance generating "overhead" traffic which is not counted against any specific RMID. As a ratio, this different view of memory bandwidth becomes more apparent at low memory bandwidths. It is not practical to enable/disable the various features that may generate memory bandwidth to give performance counters and resctrl an identical view. Instead, do not compare performance counters and resctrl view of memory bandwidth when the memory bandwidth is low. Bandwidth throttling behaves differently across platforms so it is not appropriate to drop measurement data simply based on the throttling level. Instead, use a threshold of 750MiB that has been observed to support adequate comparison between performance counters and resctrl. Signed-off-by: Reinette Chatre <reinette.chatre@intel.com> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2024-11-04selftests/resctrl: Use cache size to determine "fill_buf" buffer sizeReinette Chatre
By default the MBM and MBA tests use the "fill_buf" benchmark to read from a buffer with the goal to measure the memory bandwidth generated by this buffer access. Care should be taken when sizing the buffer used by the "fill_buf" benchmark. If the buffer is small enough to fit in the cache then it cannot be expected that the benchmark will generate much memory bandwidth. For example, on a system with 320MB L3 cache the existing hardcoded default of 250MB is insufficient. Use the measured cache size to determine a buffer size that can be expected to trigger memory access while keeping the existing default as minimum, now renamed to MINIMUM_SPAN, that has been appropriate for testing so far. Signed-off-by: Reinette Chatre <reinette.chatre@intel.com> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2024-11-04selftests/resctrl: Ensure measurements skip initialization of default benchmarkReinette Chatre
The CMT, MBA, and MBM tests rely on the resctrl_val() wrapper to start and run a benchmark while providing test specific flows via callbacks to do test specific configuration and measurements. At a high level, the resctrl_val() flow is: a) Start by fork()ing a child process that installs a signal handler for SIGUSR1 that, on receipt of SIGUSR1, will start running a benchmark. b) Assign the child process created in (a) to the resctrl control and monitoring group that dictates the memory and cache allocations with which the process can run and will contain all resctrl monitoring data of that process. c) Once parent and child are considered "ready" (determined via a message over a pipe) the parent signals the child (via SIGUSR1) to start the benchmark, waits one second for the benchmark to run, and then starts collecting monitoring data for the tests, potentially also changing allocation configuration depending on the various test callbacks. A problem with the above flow is the "black box" view of the benchmark that is combined with an arbitrarily chosen "wait one second" before measurements start. No matter what the benchmark does, it is given one second to initialize before measurements start. The default benchmark "fill_buf" consists of two parts, first it prepares a buffer (allocate, initialize, then flush), then it reads from the buffer (in unpredictable ways) until terminated. Depending on the system and the size of the buffer, the first "prepare" part may not be complete by the time the one second delay expires. Test measurements may thus start before the work needing to be measured runs. Split the default benchmark into its "prepare" and "runtime" parts and simplify the resctrl_val() wrapper while doing so. This same split cannot be done for the user provided benchmark (without a user interface change), so the current behavior is maintained for user provided benchmark. Assign the test itself to the control and monitoring group and run the "prepare" part of the benchmark in this context, ensuring it runs with required cache and memory bandwidth allocations. With the benchmark preparation complete it is only needed to fork() the "runtime" part of the benchmark (or entire user provided benchmark). Keep the "wait one second" delay before measurements start. For the default "fill_buf" benchmark this time now covers only the "runtime" portion that needs to be measured. For the user provided benchmark this delay maintains current behavior. Signed-off-by: Reinette Chatre <reinette.chatre@intel.com> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2024-11-04selftests/resctrl: Make benchmark parameter passing robustReinette Chatre
The benchmark used during the CMT, MBM, and MBA tests can be provided by the user via (-b) parameter, if not provided the default "fill_buf" benchmark is used. The user is additionally able to override any of the "fill_buf" default parameters when running the tests with "-b fill_buf <fill_buf parameters>". The "fill_buf" parameters are managed as an array of strings. Using an array of strings is complex because it requires transformations to/from strings at every producer and consumer. This is made worse for the individual tests where the default benchmark parameters values may not be appropriate and additional data wrangling is required. For example, the CMT test duplicates the entire array of strings in order to replace one of the parameters. More issues appear when combining the usage of an array of strings with the use case of user overriding default parameters by specifying "-b fill_buf <parameters>". This use case is fragile with opportunities to trigger a SIGSEGV because of opportunities for NULL pointers to exist in the array of strings. For example, by running below (thus by specifying "fill_buf" should be used but all parameters are NULL): $ sudo resctrl_tests -t mbm -b fill_buf Replace the "array of strings" parameters used for "fill_buf" with new struct fill_buf_param that contains the "fill_buf" parameters that can be used directly without transformations to/from strings. Two instances of struct fill_buf_param may exist at any point in time: * If the user provides new parameters to "fill_buf", the user parameter structure (struct user_params) will point to a fully initialized and immutable struct fill_buf_param containing the user provided parameters. * If "fill_buf" is the benchmark that should be used by a test, then the test parameter structure (struct resctrl_val_param) will point to a fully initialized struct fill_buf_param. The latter may contain (a) the user provided parameters verbatim, (b) user provided parameters adjusted to be appropriate for the test, or (c) the default parameters for "fill_buf" that is appropriate for the test if the user did not provide "fill_buf" parameters nor an alternate benchmark. The existing behavior of CMT test is to use test defined value for the buffer size even if the user provides another value via command line. This behavior is maintained since the test requires that the buffer size matches the size of the cache allocated, and the amount of cache allocated can instead be changed by the user with the "-n" command line parameter. Signed-off-by: Reinette Chatre <reinette.chatre@intel.com> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2024-11-04selftests/resctrl: Remove unused measurement codeReinette Chatre
The MBM and MBA resctrl selftests run a benchmark during which it takes measurements of read memory bandwidth via perf. Code exists to support measurements of write memory bandwidth but there exists no path with which this code can execute. While code exists for write memory bandwidth measurement there has not yet been a use case for it. Remove this unused code. Rename relevant functions to include "read" so that it is clear that it relates only to memory bandwidth reads, while renaming the functions also add consistency by changing the "membw" instances to more prevalent "mem_bw". Signed-off-by: Reinette Chatre <reinette.chatre@intel.com> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2024-11-04selftests/resctrl: Only support measured read operationReinette Chatre
The CMT, MBM, and MBA tests rely on a benchmark to generate memory traffic. By default this is the "fill_buf" benchmark that can be replaced via the "-b" command line argument. The original intent of the "-b" command line parameter was to replace the default "fill_buf" benchmark, but the implementation also exposes an alternative use case where the "fill_buf" parameters itself can be modified. One of the parameters to "fill_buf" is the "operation" that can be either "read" or "write" and indicates whether the "fill_buf" should use "read" or "write" operations on the allocated buffer. While replacing "fill_buf" default parameters is technically possible, replacing the default "read" parameter with "write" is not supported because the MBA and MBM tests only measure "read" operations. The "read" operation is also most appropriate for the CMT test that aims to use the benchmark to allocate into the cache. Avoid any potential inconsistencies between test and measurement by removing code for unsupported "write" operations to the buffer. Ignore any attempt from user space to enable this unsupported test configuration, instead always use read operations. Keep the initialization of the, now unused, "fill_buf" parameters to reserve these parameter positions since it has been exposed as an API. Future parameter additions cannot use these parameter positions. Signed-off-by: Reinette Chatre <reinette.chatre@intel.com> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2024-11-04selftests/resctrl: Remove "once" parameter required to be falseReinette Chatre
The CMT, MBM, and MBA tests rely on a benchmark that runs while the test makes changes to needed configuration (for example memory bandwidth allocation) and takes needed measurements. By default the "fill_buf" benchmark is used and by default (via its "once = false" setting) "fill_buf" is configured to run until terminated after the test completes. An unintended consequence of enabling the user to override the benchmark also enables the user to change parameters to the "fill_buf" benchmark. This enables the user to set "fill_buf" to only cycle through the buffer once (by setting "once = true") and thus breaking the CMT, MBA, and MBM tests that expect workload/interference to be reflected by their measurements. Prevent user space from changing the "once" parameter and ensure that it is always false for the CMT, MBA, and MBM tests. Suggested-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Reinette Chatre <reinette.chatre@intel.com> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2024-07-11selftests/resctrl: Remove test name comparing from write_bm_pid_to_resctrl()Ilpo Järvinen
write_bm_pid_to_resctrl() uses resctrl_val to check test name which is not a good interface generic resctrl FS functions should provide. Tests define mongrp when needed. Remove the test name check in write_bm_pid_to_resctrl() to only rely on the mongrp parameter being non-NULL. Remove write_bm_pid_to_resctrl() resctrl_val parameter and resctrl_val member from the struct resctrl_val_param that are not used anymore. Similarly, remove the test name constants that are no longer used. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Tested-by: Babu Moger <babu.moger@amd.com> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2024-07-11selftests/resctrl: Convert ctrlgrp & mongrp to pointersIlpo Järvinen
The struct resctrl_val_param has control and monitor groups as char arrays but they are not supposed to be mutated within resctrl_val(). Convert the ctrlgrp and mongrp char array within resctrl_val_param to plain const char pointers and adjust the strlen() based checks to check NULL instead. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Tested-by: Babu Moger <babu.moger@amd.com> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2024-07-11selftests/resctrl: Make some strings passed to resctrlfs functions constIlpo Järvinen
Control group, monitor group and resctrl_val are not mutated and should not be mutated within resctrlfs.c functions. Mark this by using const char * for the arguments. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Tested-by: Babu Moger <babu.moger@amd.com> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2024-07-11selftests/resctrl: Simplify bandwidth report type handlingIlpo Järvinen
bw_report is only needed for selecting the correct value from the values IMC measured. It is a member in the resctrl_val_param struct and is always set to "reads". The value is then checked in resctrl_val() using validate_bw_report_request() that besides validating the input, assumes it can mutate the string which is questionable programming practice. Simplify handling bw_report: - Convert validate_bw_report_request() into get_bw_report_type() that inputs and returns const char *. Use NULL to indicate error. - Validate the report types inside measure_mem_bw(), not in resctrl_val(). - Pass bw_report to measure_mem_bw() from ->measure() hook because resctrl_val() no longer needs bw_report for anything. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Tested-by: Babu Moger <babu.moger@amd.com> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2024-07-11selftests/resctrl: Add ->init() callback into resctrl_val_paramIlpo Järvinen
The struct resctrl_val_param is there to customize behavior inside resctrl_val() which is currently not used to full extent and there are number of strcmp()s for test name in resctrl_val done by resctrl_val(). Create ->init() hook into the struct resctrl_val_param to cleanly do per test initialization. Remove also unused branches to setup paths and the related #defines for CMT test. While touching kerneldoc, make the adjacent line consistent with the newly added form (callback vs call back). Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Tested-by: Babu Moger <babu.moger@amd.com> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2024-07-11selftests/resctrl: Add ->measure() callback to resctrl_val_paramIlpo Järvinen
The measurement done in resctrl_val() varies depending on test type. The decision for how to measure is decided based on the string compare to test name which is quite inflexible. Add ->measure() callback into the struct resctrl_val_param to allow each test to provide necessary code as a function which simplifies what resctrl_val() has to do. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Tested-by: Babu Moger <babu.moger@amd.com> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2024-07-11selftests/resctrl: Cleanup bm_pid and ppid usage & limit scopeIlpo Järvinen
'bm_pid' and 'ppid' are global variables. As they are used by different processes and in signal handler, they cannot be entirely converted into local variables. The scope of those variables can still be reduced into resctrl_val.c only. As PARENT_EXIT() macro is using 'ppid', make it a function in resctrl_val.c and pass ppid to it as an argument because it is easier to understand than using the global variable directly. Pass 'bm_pid' into measure_vals() instead of relying on the global variable which helps to make the call signatures of measure_vals() and measure_llc_resctrl() more similar to each other. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Tested-by: Babu Moger <babu.moger@amd.com> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2024-07-11selftests/resctrl: Use correct type for pidsIlpo Järvinen
A few functions receive PIDs through int arguments. PIDs variables should be of type pid_t, not int. Convert pid arguments from int to pid_t. Before printing PID, match the type to %d by casting to int which is enough for Linux (standard would allow using a longer integer type but generalizing for that would complicate the code unnecessarily, the selftest code does not need to be portable). Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Tested-by: Babu Moger <babu.moger@amd.com> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2024-05-06selftests/resctrl: Move cleanups out of individual testsMaciej Wieczor-Retman
Every test calls its cleanup function at the end of it's test function. After the cleanup function pointer is added to the test framework this can be simplified to executing the callback function at the end of the generic test running function. Make test cleanup functions static and call them from the end of run_single_test() from the resctrl_test's cleanup function pointer. Signed-off-by: Maciej Wieczor-Retman <maciej.wieczor-retman@intel.com> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2024-05-06selftests/resctrl: Simplify cleanup in ctrl-c handlerMaciej Wieczor-Retman
Ctrl-c handler isn't aware of what test is currently running. Because of that it executes all cleanups even if they aren't necessary. Since the ctrl-c handler uses the sa_sigaction system no parameters can be passed to it as function arguments. Add a global variable to make ctrl-c handler aware of the currently run test and only execute the correct cleanup callback. Signed-off-by: Maciej Wieczor-Retman <maciej.wieczor-retman@intel.com> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2024-05-06selftests/resctrl: Add cleanup function to test frameworkMaciej Wieczor-Retman
Resctrl selftests use very similar functions to cleanup after themselves. This creates a lot of code duplication. Also not being hooked to the test framework means that ctrl-c handler isn't aware of what test is currently running and executes all cleanups even though only one is needed. Add a function pointer to the resctrl_test struct and attach to it cleanup functions from individual tests. Signed-off-by: Maciej Wieczor-Retman <maciej.wieczor-retman@intel.com> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2024-02-23selftests/resctrl: Add non-contiguous CBMs CAT testMaciej Wieczor-Retman
Add tests for both L2 and L3 CAT to verify the return values generated by writing non-contiguous CBMs don't contradict the reported non-contiguous support information. Use a logical XOR to confirm return value of write_schemata() and non-contiguous CBMs support information match. Signed-off-by: Maciej Wieczor-Retman <maciej.wieczor-retman@intel.com> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2024-02-23selftests/resctrl: Add resource_info_file_exists()Maciej Wieczor-Retman
Feature checking done by resctrl_mon_feature_exists() covers features represented by the feature name presence inside the 'mon_features' file in /sys/fs/resctrl/info/L3_MON directory. There exists a different way to represent feature support and that is by the presence of 0 or 1 in a single file in the info/resource directory. In this case the filename represents what feature support is being indicated. Add a generic function to check file presence in the /sys/fs/resctrl/info/<RESOURCE> directory. Signed-off-by: Maciej Wieczor-Retman <maciej.wieczor-retman@intel.com> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2024-02-23selftests/resctrl: Split validate_resctrl_feature_request()Maciej Wieczor-Retman
validate_resctrl_feature_request() is used to test both if a resource is present in the info directory, and if a passed monitoring feature is present in the mon_features file. Refactor validate_resctrl_feature_request() into two smaller functions that each accomplish one check to give feature checking more granularity: - Resource directory presence in the /sys/fs/resctrl/info directory. - Feature name presence in the /sys/fs/resctrl/info/<RESOURCE>/mon_features file. Signed-off-by: Maciej Wieczor-Retman <maciej.wieczor-retman@intel.com> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2024-02-23selftests/resctrl: Add a helper for the non-contiguous testMaciej Wieczor-Retman
The CAT non-contiguous selftests have to read the file responsible for reporting support of non-contiguous CBMs in kernel (resctrl). Then the test compares if that information matches what is reported by CPUID output. Add a generic helper function to read an unsigned number from /sys/fs/resctrl/info/<RESOURCE>/<FILE>. Signed-off-by: Maciej Wieczor-Retman <maciej.wieczor-retman@intel.com> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2024-02-23selftests/resctrl: Add test groups and name L3 CAT test L3_CATIlpo Järvinen
To select test to run -t parameter can be used. However, -t cat currently maps to L3 CAT test which will be confusing after more CAT related tests will be added. Allow selecting tests as groups and call L3 CAT test "L3_CAT", "CAT" group will enable all CAT related tests. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Signed-off-by: Maciej Wieczor-Retman <maciej.wieczor-retman@intel.com> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2024-02-13selftests/resctrl: Get domain id from cache idIlpo Järvinen
Domain id is acquired differently depending on CPU. AMD tests use id from L3 cache, whereas CPUs from other vendors base the id on topology package id. In order to support L2 CAT test, this has to be generalized. The driver side code seems to get the domain ids from cache ids so the approach used by the AMD branch seems to match the kernel-side code. It will also work with L2 domain IDs as long as the cache level is generalized. Using the topology id was always fragile due to mismatch with the kernel-side way to acquire the domain id. It got incorrect domain id, e.g., when Cluster-on-Die (CoD) is enabled for CPU (but CoD is not well suited for resctrl in the first place so it has not been a big issue if tests don't work correctly with it). Taking all the above into account, generalize acquiring the domain id by taking it from the cache id and do not hard-code the cache level. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2024-02-13selftests/resctrl: Rename resource ID to domain IDIlpo Järvinen
Kernel-side calls the instances of a resource domains. Change the resource_id naming in the selftest code to domain_id to match the kernel side better. Suggested-by: Maciej Wieczór-Retman <maciej.wieczor-retman@intel.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2024-02-13selftests/resctrl: Pass write_schemata() resource instead of test nameIlpo Järvinen
write_schemata() takes the test name as an argument and determines the relevant resource based on the test name. Such mapping from name to resource does not really belong to resctrlfs.c that should provide only generic, test-independent functions. Pass the resource stored in the test information structure to write_schemata() instead of the test name. The new API is also more flexible as it enables to use write_schemata() for more than one resource within a test. While touching the sprintf(), move the unnecessary %c that is always '=' directly into the format string. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2024-02-13selftests/resctrl: Introduce generalized test frameworkIlpo Järvinen
Each test currently has a "run test" function in per test file and another resctrl_tests.c. The functions in resctrl_tests.c are almost identical. Generalize the one in resctrl_tests.c such that it can be shared between all of the tests. It makes adding new tests easier and removes the per test if () forests. Also add comment to CPU vendor IDs that they must be defined as bits for a bitmask. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2024-02-13selftests/resctrl: Create struct for input parametersIlpo Järvinen
resctrl_tests reads a set of parameters and passes them individually for each tests which causes variations in the call signature between the tests. Add struct input_params to hold all input parameters. It can be easily passed to every test without varying the call signature. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2024-02-13selftests/resctrl: Restore the CPU affinity after CAT testIlpo Järvinen
CAT test does not reset the CPU affinity after the benchmark. This is relatively harmless as is because CAT test is the last benchmark to run, however, more tests may be added later. Store the CPU affinity the first time taskset_benchmark() is run and add taskset_restore() which the test can call to reset the CPU mask to its original value. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2024-02-13selftests/resctrl: Rewrite Cache Allocation Technology (CAT) testIlpo Järvinen
CAT test spawns two processes into two different control groups with exclusive schemata. Both the processes alloc a buffer from memory matching their allocated LLC block size and flush the entire buffer out of caches. Since the processes are reading through the buffer only once during the measurement and initially all the buffer was flushed, the test isn't testing CAT. Rewrite the CAT test to allocate a buffer sized to half of LLC. Then perform a sequence of tests with different LLC alloc sizes starting from half of the CBM bits down to 1-bit CBM. Flush the buffer before each test and read the buffer twice. Observe the LLC misses on the second read through the buffer. As the allocated LLC block gets smaller and smaller, the LLC misses will become larger and larger giving a strong signal on CAT working properly. The new CAT test is using only a single process because it relies on measured effect against another run of itself rather than another process adding noise. The rest of the system is set to use the CBM bits not used by the CAT test to keep the test isolated. Replace count_bits() with count_contiguous_bits() to get the first bit position in order to be able to calculate masks based on it. This change has been tested with a number of systems from different generations. Suggested-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2024-02-13selftests/resctrl: Replace file write with volatile variableIlpo Järvinen
The fill_buf code prevents compiler optimizating the entire read loop away by writing the final value of the variable into a file. While it achieves the goal, writing into a file requires significant amount of work within the innermost test loop and also error handling. A simpler approach is to take advantage of volatile. Writing through a pointer to a volatile variable is enough to prevent compiler from optimizing the write away, and therefore compiler cannot remove the read loop either. Add a volatile 'value_sink' into resctrl_tests.c and make fill_buf to write into it. As a result, the error handling in fill_buf.c can be simplified. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2024-02-13selftests/resctrl: Open perf fd before start & add error handlingIlpo Järvinen
Perf fd (pe_fd) is opened, reset, and enabled during every test the CAT selftest runs. Also, ioctl(pe_fd, ...) calls are not error checked even if ioctl() could return an error. Open perf fd only once before the tests and only reset and enable the counter within the test loop. Add error checking to pe_fd ioctl() calls. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2024-02-13selftests/resctrl: Move cat_val() to cat_test.c and rename to cat_test()Ilpo Järvinen
The main CAT test function is called cat_val() and resides in cache.c which is illogical. Rename the function to cat_test() and move it into cat_test.c. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2024-02-13selftests/resctrl: Remove unnecessary __u64 -> unsigned long conversionIlpo Järvinen
Perf counters are __u64 but the code converts them to unsigned long before printing them out. Remove unnecessary type conversion and retain the perf originating value as __u64. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2024-02-13selftests/resctrl: Split show_cache_info() to test specific and generic partsIlpo Järvinen
show_cache_info() calculates results and provides generic cache information. This makes it hard to alter pass/fail conditions. Separate the test specific checks into CAT and CMT test files and leave only the generic information part into show_cache_info(). Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2024-02-13selftests/resctrl: Split measure_cache_vals()Ilpo Järvinen
measure_cache_vals() does a different thing depending on the test case that called it: - For CAT, it measures LLC misses through perf. - For CMT, it measures LLC occupancy through resctrl. Split these two functionalities into own functions the CAT and CMT tests can call directly. Replace passing the struct resctrl_val_param parameter with the filename because it's more generic and all those functions need out of resctrl_val. Co-developed-by: Fenghua Yu <fenghua.yu@intel.com> Signed-off-by: Fenghua Yu <fenghua.yu@intel.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2024-02-13selftests/resctrl: Exclude shareable bits from schemata in CAT testIlpo Järvinen
CAT test doesn't take shareable bits into account, i.e., the test might be sharing cache with some devices (e.g., graphics). Introduce get_mask_no_shareable() and use it to provision an environment for CAT test where the allocated LLC is isolated better. Excluding shareable_bits may create hole(s) into the cbm_mask, thus add a new helper count_contiguous_bits() to find the longest contiguous set of CBM bits. create_bit_mask() is needed by an upcoming CAT test rewrite so make it available in resctrl.h right away. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2024-02-13selftests/resctrl: Create cache_portion_size() helperIlpo Järvinen
CAT and CMT tests calculate size of the cache portion for the n-bits cache allocation on their own. Add cache_portion_size() helper that calculates size of the cache portion for the given number of bits and use it to replace the existing span calculations. This also prepares for the new CAT test that will need to determine the size of the cache portion also during results processing. Rename also 'cache_size' local variables to 'cache_total_size' to prevent misinterpretations. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2024-02-13selftests/resctrl: Mark get_cache_size() cache_type constIlpo Järvinen
get_cache_size() does not modify cache_type so it could be const. Mark cache_type const so that const char * can be passed to it. This prevents warnings once many of the test parameters are marked const. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2024-02-13selftests/resctrl: Refactor get_cbm_mask() and rename to get_full_cbm()Ilpo Järvinen
Callers of get_cbm_mask() are required to pass a string into which the capacity bitmask (CBM) is read. Neither CAT nor CMT tests need the bitmask as string but just convert it into an unsigned long value. Another limitation is that the bit mask reader can only read .../cbm_mask files. Generalize the bit mask reading function into get_bit_mask() such that it can be used to handle other files besides the .../cbm_mask and handles the unsigned long conversion within get_bit_mask() using fscanf(). Change get_cbm_mask() to use get_bit_mask() and rename it to get_full_cbm() to better indicate what the function does. Return error from get_full_cbm() if the bitmask is zero for some reason because it makes the code more robust as the selftests naturally assume the bitmask has some bits. Also mark cache_type const while at it and remove useless comments that are related to processing of CBM bits. Co-developed-by: Fenghua Yu <fenghua.yu@intel.com> Signed-off-by: Fenghua Yu <fenghua.yu@intel.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2024-02-13selftests/resctrl: Refactor fill_buf functionsIlpo Järvinen
There are unnecessary nested calls in fill_buf.c: - run_fill_buf() calls fill_cache() - alloc_buffer() calls malloc_and_init_memory() Simplify the code flow and remove those unnecessary call levels by moving the called code inside the calling function and remove the duplicated error print. Resolve the difference in run_fill_buf() and fill_cache() parameter name into 'buf_size' which is more descriptive than 'span'. Also, while moving the allocation related code, rename 'p' into 'buf' to be consistent in naming the variables. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2024-02-13selftests/resctrl: Convert perror() to ksft_perror() or ksft_print_msg()Ilpo Järvinen
The resctrl selftest code contains a number of perror() calls. Some of them come with hash character and some don't. The kselftest framework provides ksft_perror() that is compatible with test output formatting so it should be used instead of adding custom hash signs. Some perror() calls are too far away from anything that sets error. For those call sites, ksft_print_msg() must be used instead. Convert perror() to ksft_perror() or ksft_print_msg(). Other related changes: - Remove hash signs - Remove trailing stops & newlines from ksft_perror() - Add terminating newlines for converted ksft_print_msg() - Use consistent capitalization - Small fixes/tweaks to typos & grammar of the messages - Extract error printing out of PARENT_EXIT() to be able to differentiate Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2023-10-13selftests/resctrl: Move run_benchmark() to a more fitting fileMaciej Wieczor-Retman
resctrlfs.c contains mostly functions that interact in some way with resctrl FS entries while functions inside resctrl_val.c deal with measurements and benchmarking. run_benchmark() is located in resctrlfs.c even though it's purpose is not interacting with the resctrl FS but to execute cache checking logic. Move run_benchmark() to resctrl_val.c just before resctrl_val() that makes use of run_benchmark(). Make run_benchmark() static since it's not used between multiple files anymore. Remove return comment from kernel-doc since the function is type void. Signed-off-by: Maciej Wieczor-Retman <maciej.wieczor-retman@intel.com> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2023-10-13selftests/resctrl: Refactor feature check to use resource and feature nameIlpo Järvinen
Feature check in validate_resctrl_feature_request() takes in the test name string and maps that to what to check per test. Pass resource and feature names to validate_resctrl_feature_request() directly rather than deriving them from the test name inside the function which makes the feature check easier to extend for new test cases. Use !! in the return statement to make the boolean conversion more obvious even if it is not strictly necessary from correctness point of view (to avoid it looking like the function is returning a freed pointer). Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Tested-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Reviewed-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> Cc: <stable@vger.kernel.org> # selftests/resctrl: Remove duplicate feature check from CMT test Cc: <stable@vger.kernel.org> # selftests/resctrl: Move _GNU_SOURCE define into Makefile Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2023-10-13selftests/resctrl: Move _GNU_SOURCE define into MakefileIlpo Järvinen
_GNU_SOURCE is defined in resctrl.h. Defining _GNU_SOURCE has a large impact on what gets defined when including headers either before or after it. This can result in compile failures if .c file decides to include a standard header file before resctrl.h. It is safer to define _GNU_SOURCE in Makefile so it is always defined regardless of in which order includes are done. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Tested-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Reviewed-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> Cc: <stable@vger.kernel.org> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2023-10-13selftests/resctrl: Make benchmark command const and build it with pointersIlpo Järvinen
Benchmark command is used in multiple tests so it should not be mutated by the tests but CMT test alters span argument. Due to the order of tests (CMT test runs last), mutating the span argument in CMT test does not trigger any real problems currently. Mark benchmark_cmd strings as const and setup the benchmark command using pointers. Because the benchmark command becomes const, the input arguments can be used directly. Besides being simpler, using the input arguments directly also removes the internal size restriction. CMT test has to create a copy of the benchmark command before altering the benchmark command. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Tested-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> Reviewed-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Reviewed-by: "Wieczor-Retman, Maciej" <maciej.wieczor-retman@intel.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2023-10-13selftests/resctrl: Simplify span lifetimeIlpo Järvinen
struct resctrl_val_param contains span member. resctrl_val(), however, never uses it because the value of span is embedded into the default benchmark command and parsed from it by run_benchmark(). Remove span from resctrl_val_param. Provide DEFAULT_SPAN for the code that needs it. CMT and CAT tests communicate span that is different from the DEFAULT_SPAN between their internal functions which is converted into passing it directly as a parameter. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Tested-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Reviewed-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> Reviewed-by: "Wieczor-Retman, Maciej" <maciej.wieczor-retman@intel.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2023-10-13selftests/resctrl: Remove bw_report and bm_type from main()Ilpo Järvinen
bw_report is always set to "reads" and bm_type is set to "fill_buf" but is never used. Set bw_report directly to "reads" in MBA/MBM test and remove bm_type. Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Tested-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Reviewed-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com> Reviewed-by: "Wieczor-Retman, Maciej" <maciej.wieczor-retman@intel.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2023-07-25selftests/resctrl: Don't use variable argument list for ->setup()Ilpo Järvinen
struct resctrl_val_param has ->setup() function that accepts variable argument list. All test cases use only 1 argument as input and it's the struct resctrl_val_param pointer. Instead of variable argument list, directly pass struct resctrl_val_param pointer as the only parameter to ->setup(). Co-developed-by: Fenghua Yu <fenghua.yu@intel.com> Signed-off-by: Fenghua Yu <fenghua.yu@intel.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Tested-by: Babu Moger <babu.moger@amd.com> Tested-by: Shaopeng Tan (Fujitsu) <tan.shaopeng@fujitsu.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2023-07-25selftests/resctrl: Don't pass test name to fill_bufIlpo Järvinen
Test name is passed to fill_buf functions so that they can loop around buffer only once. This is required for CAT test case. To loop around buffer only once, caller doesn't need to let fill_buf know which test case it is. Instead, pass a boolean argument 'once' which makes fill_buf more generic. As run_benchmark() no longer needs to pass the test name to run_fill_buf(), a few test running functions can be simplified to not write the test name into the default benchmark_cmd. The has_ben argument can also be removed now from those test running functions. Co-developed-by: Fenghua Yu <fenghua.yu@intel.com> Signed-off-by: Fenghua Yu <fenghua.yu@intel.com> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Tested-by: Babu Moger <babu.moger@amd.com> Tested-by: Shaopeng Tan (Fujitsu) <tan.shaopeng@fujitsu.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>