selftests/resctrl: Add non-contiguous CBMs CAT test

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>

selftests/resctrl: Add resource_info_file_exists()

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>

selftests/resctrl: Split validate_resctrl_feature_request()

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>

selftests/resctrl: Add a helper for the non-contiguous test

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>

selftests/resctrl: Add test groups and name L3 CAT test L3_CAT

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>

selftests/resctrl: Get domain id from cache id

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>

selftests/resctrl: Rename resource ID to domain ID

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>

selftests/resctrl: Pass write_schemata() resource instead of test name

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>

selftests/resctrl: Introduce generalized test framework

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>

selftests/resctrl: Create struct for input parameters

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>

selftests/resctrl: Restore the CPU affinity after CAT test

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>

selftests/resctrl: Rewrite Cache Allocation Technology (CAT) test

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>

selftests/resctrl: Replace file write with volatile variable

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>

selftests/resctrl: Open perf fd before start & add error handling

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>

selftests/resctrl: Move cat_val() to cat_test.c and rename to cat_test()

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>

selftests/resctrl: Remove unnecessary __u64 -> unsigned long conversion

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>

selftests/resctrl: Split show_cache_info() to test specific and generic parts

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>

selftests/resctrl: Split measure_cache_vals()

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>

selftests/resctrl: Exclude shareable bits from schemata in CAT test

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>

selftests/resctrl: Create cache_portion_size() helper

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>

selftests/resctrl: Mark get_cache_size() cache_type const

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>

selftests/resctrl: Refactor get_cbm_mask() and rename to get_full_cbm()

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>

selftests/resctrl: Refactor fill_buf functions

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>

selftests/resctrl: Convert perror() to ksft_perror() or ksft_print_msg()

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>

selftests/resctrl: Move run_benchmark() to a more fitting file

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>

selftests/resctrl: Refactor feature check to use resource and feature name

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>

selftests/resctrl: Move _GNU_SOURCE define into Makefile

_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>

selftests/resctrl: Make benchmark command const and build it with pointers

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>

selftests/resctrl: Simplify span lifetime

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>

selftests/resctrl: Remove bw_report and bm_type from main()

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>

selftests/resctrl: Don't use variable argument list for ->setup()

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>

selftests/resctrl: Don't pass test name to fill_buf

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>

selftests/resctrl: Remove "malloc_and_init_memory" param from run_fill_buf()

run_fill_buf()'s malloc_and_init_memory parameter is always 1. There's
also duplicated memory init code for malloc_and_init_memory == 0 case
in fill_buf() which is unused.

Remove the malloc_and_init_memory parameter and the duplicated mem init
code.

While at it, fix also a typo in run_fill_buf() prototype's argument.

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>

selftests/resctrl: Convert span to size_t

Span is defined either as unsigned long or int.

Consistently use size_t everywhere for span as it refers to size of the
memory block.

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>
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>

selftests/resctrl: Remove mum_resctrlfs from struct resctrl_val_param

Resctrl FS mount/umount are now cleanly paired leaving .mum_resctrlfs
in the struct resctrl_val_param unused.

Remove .mum_resctrlfs from struct resctrl_val_param.

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>

selftests/resctrl: Refactor remount_resctrl(bool mum_resctrlfs) to mount_resctrl()

Mount/umount of the resctrl FS is now paired nicely per test.

Rename remount_resctrl(bool mum_resctrlfs) to mount_resctrl(). Make
it unconditionally try to mount the resctrl FS and return error if
resctrl FS was mounted already.

While at it, group the mount/umount prototypes in the header.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.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>

selftests/resctrl: Unmount resctrl FS if child fails to run benchmark

A child calls PARENT_EXIT() when it fails to run a benchmark to kill
the parent process. PARENT_EXIT() lacks unmount for the resctrl FS and
the parent won't be there to unmount it either after it gets killed.

Add the resctrl FS unmount also to PARENT_EXIT().

Fixes: 591a6e8588fc ("selftests/resctrl: Add basic resctrl file system operations and data")
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>

selftests/resctrl: Commonize the signal handler register/unregister for all tests

After creating a child process with fork() in CAT test, if a signal such
as SIGINT is received, the parent process will be terminated immediately,
and therefore the child process will not be killed and also resctrlfs is
not unmounted.

There is a signal handler registered in CMT/MBM/MBA tests, which kills
child process, unmount resctrlfs, cleanups result files, etc., if a
signal such as SIGINT is received.

Commonize the signal handler registered for CMT/MBM/MBA tests and
reuse it in CAT.

To reuse the signal handler to kill child process use global bm_pid
instead of local bm_pid.

Also, since the MBA/MBA/CMT/CAT are run in order, unregister the signal
handler at the end of each test so that the signal handler cannot be
inherited by other tests.

Reviewed-by: Ilpo Jarvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

selftests/resctrl: Use remount_resctrlfs() consistently with boolean

remount_resctrlfs() accepts a boolean value as an argument. Some tests
pass 0/1 and some tests pass true/false.

Make all the callers of remount_resctrlfs() use true/false so that the
parameter usage is consistent across tests.

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>

selftests/resctrl: Change name from CBM_MASK_PATH to INFO_PATH

CBM_MASK_PATH is actually the path to resctrl/info.

Change the macro name to correctly indicate what it represents.

[ ij: Tweaked the changelog. ]

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>

selftests/resctrl: Allow ->setup() to return errors

resctrl_val() assumes ->setup() always returns either 0 to continue
tests or < 0 in case of the normal termination of tests after x runs.
The latter overlaps with normal error returns.

Define END_OF_TESTS (=1) to differentiate the normal termination of
tests and return errors as negative values. Alter callers of ->setup()
to handle errors properly.

Fixes: 790bf585b0ee ("selftests/resctrl: Add Cache Allocation Technology (CAT) selftest")
Fixes: ecdbb911f22d ("selftests/resctrl: Add MBM test")
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>

selftests/resctrl: Extend CPU vendor detection

Currently, the resctrl_tests only has a function to detect AMD vendor.
Since when the Intel Sub-NUMA Clustering feature is enabled,
Intel CMT and MBM counters may not be accurate,
the resctrl_tests also need a function to detect Intel vendor.
And in the future, resctrl_tests will need a function to detect different
vendors, such as Arm.

Extend the function to detect Intel vendor as well. Also,
this function can be easily extended to detect other vendors.

Signed-off-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

selftests/resctrl: Use resctrl/info for feature detection

Resctrl test suite before running any unit test (like cmt, cat, mbm and
mba) should first check if the feature is enabled (by kernel and not just
supported by H/W) on the platform or not.
validate_resctrl_feature_request() is supposed to do that. This function
intends to grep for relevant flags in /proc/cpuinfo but there are several
issues here

1. validate_resctrl_feature_request() calls fgrep() to get flags from
/proc/cpuinfo. But, fgrep() can only return a string with maximum of 255
characters and hence the complete cpu flags are never returned.
2. The substring search logic is also busted. If strstr() finds requested
resctrl feature in the cpu flags, it returns pointer to the first
occurrence. But, the logic negates the return value of strstr() and
hence validate_resctrl_feature_request() returns false if the feature is
present in the cpu flags and returns true if the feature is not present.
3. validate_resctrl_feature_request() checks if a resctrl feature is
reported in /proc/cpuinfo flags or not. Having a cpu flag means that the
H/W supports the feature, but it doesn't mean that the kernel enabled
it. A user could selectively enable only a subset of resctrl features
using kernel command line arguments. Hence, /proc/cpuinfo isn't a
reliable source to check if a feature is enabled or not.

The 3rd issue being the major one and fixing it requires changing the way
validate_resctrl_feature_request() works. Since, /proc/cpuinfo isn't the
right place to check if a resctrl feature is enabled or not, a more
appropriate place is /sys/fs/resctrl/info directory. Change
validate_resctrl_feature_request() such that,

1. For cat, check if /sys/fs/resctrl/info/L3 directory is present or not
2. For mba, check if /sys/fs/resctrl/info/MB directory is present or not
3. For cmt, check if /sys/fs/resctrl/info/L3_MON directory is present and
check if /sys/fs/resctrl/info/L3_MON/mon_features has llc_occupancy
4. For mbm, check if /sys/fs/resctrl/info/L3_MON directory is present and
check if /sys/fs/resctrl/info/L3_MON/mon_features has
mbm_<total/local>_bytes

Please note that only L3_CAT, L3_CMT, MBA and MBM are supported. CDP and L2
variants can be added later.

Reported-by: Reinette Chatre <reinette.chatre@intel.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

selftests/resctrl: Share show_cache_info() by CAT and CMT tests

show_cache_info() functions are defined separately in CAT and CMT
tests. But the functions are same for the tests and unnecessary
to be defined separately. Share the function by the tests.

Suggested-by: Shuah Khan <skhan@linuxfoundation.org>
Tested-by: Babu Moger <babu.moger@amd.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

selftests/resctrl: Call kselftest APIs to log test results

Call kselftest APIs instead of using printf() to log test results
for cleaner code and better future extension.

Suggested-by: Shuah Khan <skhan@linuxfoundation.org>
Tested-by: Babu Moger <babu.moger@amd.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

selftests/resctrl: Rename CQM test as CMT test

CMT (Cache Monitoring Technology) [1] is a H/W feature that reports cache
occupancy of a process. resctrl selftest suite has a unit test to test CMT
for LLC but the test is named as CQM (Cache Quality Monitoring).
Furthermore, the unit test source file is named as cqm_test.c and several
functions, variables, comments, preprocessors and statements widely use
"cqm" as either suffix or prefix. This rampant misusage of CQM for CMT
might confuse someone who is newly looking at resctrl selftests because
this feature is named CMT in the Intel Software Developer's Manual.

Hence, rename all the occurrences (unit test source file name, functions,
variables, comments and preprocessors) of cqm with cmt.

[1] Please see Intel SDM, Volume 3, chapter 17 and section 18 for more
information on CMT: https://software.intel.com/content/www/us/en/develop/articles/intel-sdm.html

Suggested-by: Reinette Chatre <reinette.chatre@intel.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

selftests/resctrl: Clean up resctrl features check

Checking resctrl features call strcmp() to compare feature strings
(e.g. "mba", "cat" etc). The checkings are error prone and don't have
good coding style. Define the constant strings in macros and call
strncmp() to solve the potential issues.

Suggested-by: Shuah Khan <skhan@linuxfoundation.org>
Tested-by: Babu Moger <babu.moger@amd.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

selftests/resctrl: Fix compilation issues for other global variables

Reinette reported following compilation issue on Fedora 32, gcc version
10.1.1

/usr/bin/ld: resctrl_tests.o:<src_dir>/resctrl.h:65: multiple definition
of `bm_pid'; cache.o:<src_dir>/resctrl.h:65: first defined here

Other variables are ppid, tests_run, llc_occup_path, is_amd. Compiler
isn't happy because these variables are defined globally in two .c files
but are not declared as extern.

To fix issues for the global variables, declare them as extern.

Chang Log:
- Split this patch from v4's patch 1 (Shuah).

Reported-by: Reinette Chatre <reinette.chatre@intel.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

selftests/resctrl: Fix compilation issues for global variables

Reinette reported following compilation issue on Fedora 32, gcc version
10.1.1

/usr/bin/ld: cqm_test.o:<src_dir>/cqm_test.c:22: multiple definition of
`cache_size'; cat_test.o:<src_dir>/cat_test.c:23: first defined here

The same issue is reported for long_mask, cbm_mask, count_of_bits etc
variables as well. Compiler isn't happy because these variables are
defined globally in two .c files namely cqm_test.c and cat_test.c and
the compiler during compilation finds that the variable is already
defined (multiple definition error).

Taking a closer look at the usage of these variables reveals that these
variables are used only locally in functions such as cqm_resctrl_val()
(defined in cqm_test.c) and cat_perf_miss_val() (defined in cat_test.c).
These variables are not shared between those functions. So, there is no
need for these variables to be global. Hence, fix this issue by making
them static variables.

Reported-by: Reinette Chatre <reinette.chatre@intel.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

selftests/resctrl: Add vendor detection mechanism

RESCTRL feature is supported both on Intel and AMD now. Some features
are implemented differently. Add vendor detection mechanism. Use the vendor
check where there are differences.

Signed-off-by: Babu Moger <babu.moger@amd.com>
Co-developed-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

selftests/resctrl: Add Cache Allocation Technology (CAT) selftest

Cache Allocation Technology (CAT) selftest allocates a portion of
last level cache and starts a benchmark to read each cache
line in this portion of cache. Measure the cache misses in perf and
the misses should be equal to the number of cache lines in this
portion of cache.

We don't use CQM to calculate cache usage because some CAT enabled
platforms don't have CQM.

Co-developed-by: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Signed-off-by: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Co-developed-by: Babu Moger <babu.moger@amd.com>
Signed-off-by: Babu Moger <babu.moger@amd.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

selftests/resctrl: Add Cache QoS Monitoring (CQM) selftest

Cache QoS Monitoring (CQM) selftest starts stressful cache benchmark
with specified size of memory to access the cache. Last Level cache
occupancy reported by CQM should be close to the size of the memory.

Co-developed-by: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Signed-off-by: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Co-developed-by: Babu Moger <babu.moger@amd.com>
Signed-off-by: Babu Moger <babu.moger@amd.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

selftests/resctrl: Add MBA test

MBA (Memory Bandwidth Allocation) test starts a stressful memory
bandwidth benchmark and allocates memory bandwidth from 100% down
to 10% for the benchmark process. For each allocation, compare
perf IMC counter and mbm total bytes from resctrl. The difference
between the two values should be within a threshold to pass the test.

Default benchmark is built-in fill_buf. But users can specify their
own benchmark by option "-b".

We can add memory bandwidth allocation for multiple processes in the
future.

Co-developed-by: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Signed-off-by: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Co-developed-by: Babu Moger <babu.moger@amd.com>
Signed-off-by: Babu Moger <babu.moger@amd.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

selftests/resctrl: Add MBM test

MBM (Memory Bandwidth Monitoring) test is the first implemented selftest.
It starts a stressful memory bandwidth benchmark and assigns the
bandwidth pid in a resctrl monitoring group. Read and compare perf IMC
counter and MBM total bytes for the benchmark. The numbers should be
close enough to pass the test.

Default benchmark is built-in fill_buf. But users can specify their
own benchmark by option "-b".

We can add memory bandwidth monitoring for multiple processes in the
future.

Co-developed-by: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Signed-off-by: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Co-developed-by: Babu Moger <babu.moger@amd.com>
Signed-off-by: Babu Moger <babu.moger@amd.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

selftests/resctrl: Add callback to start a benchmark

The callback starts a child process and puts the child pid in created
resctrl group with specified memory bandwidth in schemata. The child
starts running benchmark.

Signed-off-by: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Co-developed-by: Babu Moger <babu.moger@amd.com>
Signed-off-by: Babu Moger <babu.moger@amd.com>
Co-developed-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

selftests/resctrl: Add basic resctrl file system operations and data

The basic resctrl file system operations and data are added for future
usage by resctrl selftest tool.

Signed-off-by: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Co-developed-by: Babu Moger <babu.moger@amd.com>
Signed-off-by: Babu Moger <babu.moger@amd.com>
Co-developed-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>