The CMT test creates a new control group that is also capable of monitoring
and assigns the workload to it. The workload allocates a buffer that by
default fills a portion of the L3 and keeps reading from the buffer,
measuring the L3 occupancy at intervals. The test passes if the workload's
L3 occupancy is within 15% of the buffer size.
The CMT test does not take into account that some of the workload's data
may land in L2/L1. Matching L3 occupancy to the size of the buffer while
a portion of the buffer can be allocated into L2 is not accurate.
Take the L2 cache into account to improve test accuracy:
- Reduce the workload's L2 cache allocation to the minimum on systems that
support L2 cache allocation. Do so with a new utility in preparation for
all L3 cache allocation tests needing the same capability.
- Increase the buffer size to accommodate data that may be allocated into
the L2 cache. Use a buffer size double the L3 portion to keep using the
L3 portion size as goal for L3 occupancy while taking into account that
some of the data may be in L2.
Running the CMT test on a sample system while introducing significant
cache misses using "stress-ng --matrix-3d 0 --matrix-3d-zyx" shows
significant improvement in L3 cache occupancy:
Before:
# Starting CMT test ...
# Mounting resctrl to "/sys/fs/resctrl"
# Cache size :335544320
# Writing benchmark parameters to resctrl FS
# Write schema "L3:0=fffe0" to resctrl FS
# Write schema "L3:0=1f" to resctrl FS
# Benchmark PID: 7089
# Checking for pass/fail
# Pass: Check cache miss rate within 15%
# Percent diff=12
# Number of bits: 5
# Average LLC val: 73269248
# Cache span (bytes): 83886080
ok 1 CMT: test
After:
# Starting CMT test ...
# Mounting resctrl to "/sys/fs/resctrl"
# Cache size :335544320
# Writing benchmark parameters to resctrl FS
# Write schema "L3:0=fffe0" to resctrl FS
# Write schema "L3:0=1f" to resctrl FS
# Write schema "L2:1=0x1" to resctrl FS
# Benchmark PID: 7171
# Checking for pass/fail
# Pass: Check cache miss rate within 15%
# Percent diff=0
# Number of bits: 5
# Average LLC val: 83755008
# Cache span (bytes): 83886080
ok 1 CMT: test
Link: https://lore.kernel.org/r/00445fa64c251b86b86023f87220ee1ad8561460.1775266384.git.reinette.chatre@intel.com
Reported-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Tested-by: Chen Yu <yu.c.chen@intel.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/lkml/aO+7MeSMV29VdbQs@e133380.arm.com/
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
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>
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>
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>
Perf related variables pea_llc_miss, pe_read, and pe_fd are globals in
cache.c.
Convert them to locals for better scoping and make pea_llc_miss simpler
by renaming it to pea. Make close(pe_fd) handling easier to understand
by doing it inside cat_val().
Make also sizeof()s use safer way to determine the right struct.
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>
struct perf_event_attr initialization is spread into
perf_event_initialize() and perf_event_attr_initialize() and setting
->config is hardcoded by the deepest level.
perf_event_attr init belongs to perf_event_attr_initialize() so move it
entirely there. Rename the other function
perf_event_initialized_read_format().
Call each init function directly from the test as they will take
different parameters (especially true after the perf related global
variables are moved to local 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>
Naming for perf event related functions, types, and variables is
inconsistent.
Make struct read_format and all functions related to perf events start
with "perf_". Adjust variable names towards the same direction but use
shorter names for variables where appropriate (pe prefix).
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>
Perf event handling has functions that are the sole caller of another
perf event handling related function:
- reset_enable_llc_perf() calls perf_event_open_llc_miss()
- perf_event_measure() calls get_llc_perf()
Remove the extra layer of calls to make the code easier to follow by
moving the code into the calling function.
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>
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>
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>
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>
A number function comments state the function return non-zero on
failure but in reality they can only return 0 on success and < 0 on
error.
Update the comments to say < 0 on error to match the behavior.
While at it, improve cat_val() comment to state that 0 means the test
was run (either pass or fail).
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>
perf_event_open_llc_miss() calls ctrlc_handler() to cleanup if
perf_event_open() returns an error. Those cleanups, however, are not
the responsibility of perf_event_open_llc_miss() and it thus interferes
unnecessarily with the usual cleanup pattern. Worse yet,
ctrlc_handler() calls exit() in the end preventing the ordinary cleanup
done in the calling function from executing.
ctrlc_handler() should only be used as a signal handler, not during
normal error handling.
Remove call to ctrlc_handler() from perf_event_open_llc_miss(). As
unmounting resctrlfs and test cleanup are already handled properly
by error rollbacks in the calling functions, no other changes are
necessary.
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>
A number of functions in the resctrl selftests return errno. It is
problematic because errno is positive which is often counterintuitive.
Also, every site returning errno prints the error message already with
ksft_perror() so there is not much added value in returning the precise
error code.
Simply convert all places returning errno to return -1 that is typical
userspace error code in case of failures.
While at it, improve resctrl_val() comment to state that 0 means the
test was run (either pass or fail).
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>
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>
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>
Compiling resctrl selftest after adding a __printf() attribute to
ksft_print_msg() exposes -Wformat warning in show_cache_info().
The format specifier used expects a variable of type int but a long
unsigned int variable is passed instead.
Change the format specifier to match the passed variable.
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>
Results include warm-up test which is discarded before passing the sum
to show_cache_info(). show_cache_info() handles this by subtracting one
from the number of tests in divisor. It is a trappy construct to have
sum and number of tests parameters to disagree like this.
A more logical place for subtracting the skipped tests is where the sum
is calculated so move it there. Pass the correct number of tests to
show_cache_info() so it can be used directly as the divisor for
calculating the average.
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>
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>
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>
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>
Perf event fd (fd_lm) is not closed when run_fill_buf() returns error.
Close fd_lm only in cat_val() to make it easier to track it is always
closed.
Fixes: 790bf585b0 ("selftests/resctrl: Add Cache Allocation Technology (CAT) selftest")
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>
