selftests/resctrl: Adjust effective L3 cache size with SNC enabled

Sub-NUMA Cluster divides CPUs sharing an L3 cache into separate NUMA
nodes. Systems may support splitting into either two, three, f

selftests/resctrl: Adjust effective L3 cache size with SNC enabled

Sub-NUMA Cluster divides CPUs sharing an L3 cache into separate NUMA
nodes. Systems may support splitting into either two, three, four or six
nodes. When SNC mode is enabled the effective amount of L3 cache
available for allocation is divided by the number of nodes per L3.

It's possible to detect which SNC mode is active by comparing the number
of CPUs that share a cache with CPU0, with the number of CPUs on node0.

Detect SNC mode once and let other tests inherit that information.

Update CFLAGS after including lib.mk in the Makefile so that fallthrough
macro can be used.

To check if SNC detection is reliable one can check the
/sys/devices/system/cpu/offline file. If it's empty, it means all cores
are operational and the ratio should be calculated correctly. If it has
any contents, it means the detected SNC mode can't be trusted and should
be disabled.

Check if detection was not reliable due to offline cpus. If it was skip
running tests since the results couldn't be trusted.

Co-developed-by: Tony Luck <[email protected]>
Signed-off-by: Tony Luck <[email protected]>
Signed-off-by: Maciej Wieczor-Retman <[email protected]>
Reviewed-by: Reinette Chatre <[email protected]>
Signed-off-by: Shuah Khan <[email protected]>

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selftests: centralize -D_GNU_SOURCE= to CFLAGS in lib.mk

Centralize the _GNU_SOURCE definition to CFLAGS in lib.mk. Remove
redundant defines from Makefiles that import lib.mk. Convert any usage of

selftests: centralize -D_GNU_SOURCE= to CFLAGS in lib.mk

Centralize the _GNU_SOURCE definition to CFLAGS in lib.mk. Remove
redundant defines from Makefiles that import lib.mk. Convert any usage of
"#define _GNU_SOURCE 1" to "#define _GNU_SOURCE".

This uses the form "-D_GNU_SOURCE=", which is equivalent to
"#define _GNU_SOURCE".

Otherwise using "-D_GNU_SOURCE" is equivalent to "-D_GNU_SOURCE=1" and
"#define _GNU_SOURCE 1", which is less commonly seen in source code and
would require many changes in selftests to avoid redefinition warnings.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Edward Liaw <[email protected]>
Suggested-by: John Hubbard <[email protected]>
Acked-by: Shuah Khan <[email protected]>
Reviewed-by: Muhammad Usama Anjum <[email protected]>
Cc: Albert Ou <[email protected]>
Cc: André Almeida <[email protected]>
Cc: Darren Hart <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: Davidlohr Bueso <[email protected]>
Cc: David S. Miller <[email protected]>
Cc: Eric Dumazet <[email protected]>
Cc: Eric W. Biederman <[email protected]>
Cc: Fenghua Yu <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Jakub Kicinski <[email protected]>
Cc: Jarkko Sakkinen <[email protected]>
Cc: Jason Gunthorpe <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Kevin Tian <[email protected]>
Cc: Palmer Dabbelt <[email protected]>
Cc: Paolo Abeni <[email protected]>
Cc: Paolo Bonzini <[email protected]>
Cc: Paul Walmsley <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Reinette Chatre <[email protected]>
Cc: Sean Christopherson <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

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selftests/resctrl: fix clang build failure: use LOCAL_HDRS

First of all, in order to build with clang at all, one must first apply
Valentin Obst's build fix for LLVM [1]. Once that is done, then whe

selftests/resctrl: fix clang build failure: use LOCAL_HDRS

First of all, in order to build with clang at all, one must first apply
Valentin Obst's build fix for LLVM [1]. Once that is done, then when
building with clang, via:

make LLVM=1 -C tools/testing/selftests

...the following error occurs:

clang: error: cannot specify -o when generating multiple output files

This is because clang, unlike gcc, won't accept invocations of this
form:

clang file1.c header2.h

Fix this by using selftests/lib.mk facilities for tracking local header
file dependencies: add them to LOCAL_HDRS, leaving only the .c files to
be passed to the compiler.

[1] https://lore.kernel.org/all/20240329-selftests-libmk-llvm-rfc-v1-1-2f9ed7d1c49f@valentinobst.de/

Fixes: 8e289f454289 ("selftests/resctrl: Add resctrl.h into build deps")
Cc: Ilpo Järvinen <[email protected]>
Signed-off-by: John Hubbard <[email protected]>
Acked-by: Reinette Chatre <[email protected]>
Signed-off-by: Shuah Khan <[email protected]>

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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
aft

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 <[email protected]>
Tested-by: Shaopeng Tan <[email protected]>
Reviewed-by: Reinette Chatre <[email protected]>
Reviewed-by: Shaopeng Tan <[email protected]>
Cc: <[email protected]>
Signed-off-by: Shuah Khan <[email protected]>

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selftests/resctrl: Add resctrl.h into build deps

Makefile only lists *.c as build dependencies for the resctrl_tests
executable which excludes resctrl.h.

Add *.h to wildcard() to include resctrl.h.

selftests/resctrl: Add resctrl.h into build deps

Makefile only lists *.c as build dependencies for the resctrl_tests
executable which excludes resctrl.h.

Add *.h to wildcard() to include resctrl.h.

Fixes: 591a6e8588fc ("selftests/resctrl: Add basic resctrl file system operations and data")
Signed-off-by: Ilpo Järvinen <[email protected]>
Reviewed-by: Reinette Chatre <[email protected]>
Tested-by: Babu Moger <[email protected]>
Tested-by: Shaopeng Tan (Fujitsu) <[email protected]>
Signed-off-by: Shuah Khan <[email protected]>

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selftests/resctrl: Add missing SPDX license to Makefile

Add the missing SPDX(SPDX-License-Identifier) license header to
tools/testing/selftests/resctrl/Makefile.

Acked-by: Reinette Chatre <reinette

selftests/resctrl: Add missing SPDX license to Makefile

Add the missing SPDX(SPDX-License-Identifier) license header to
tools/testing/selftests/resctrl/Makefile.

Acked-by: Reinette Chatre <[email protected]>
Reviewed-by: Fenghua Yu <[email protected]>
Signed-off-by: Shaopeng Tan <[email protected]>
Signed-off-by: Shuah Khan <[email protected]>

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selftests/resctrl: Make resctrl_tests run using kselftest framework

In kselftest framework, all tests can be build/run at a time,
and a sub test also can be build/run individually. As follows:
$ mak

selftests/resctrl: Make resctrl_tests run using kselftest framework

In kselftest framework, all tests can be build/run at a time,
and a sub test also can be build/run individually. As follows:
$ make kselftest-all TARGETS=resctrl
$ make -C tools/testing/selftests run_tests
$ make -C tools/testing/selftests TARGETS=resctrl run_tests

However, resctrl_tests cannot be run using kselftest framework,
users have to change directory to tools/testing/selftests/resctrl/,
run "make" to build executable file "resctrl_tests",
and run "sudo ./resctrl_tests" to execute the test.

To build/run resctrl_tests using kselftest framework.
Modify tools/testing/selftests/Makefile
and tools/testing/selftests/resctrl/Makefile.

Even after this change, users can still build/run resctrl_tests
without using framework as before.

Reviewed-by: Reinette Chatre <[email protected]> # resctrl changes
Reviewed-by: Fenghua Yu <[email protected]>
Signed-off-by: Shaopeng Tan <[email protected]>
Signed-off-by: Shuah Khan <[email protected]>

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selftests/resctrl: Enable gcc checks to detect buffer overflows

David reported a buffer overflow error in the check_results() function of
the cmt unit test and he suggested enabling _FORTIFY_SOURCE

selftests/resctrl: Enable gcc checks to detect buffer overflows

David reported a buffer overflow error in the check_results() function of
the cmt unit test and he suggested enabling _FORTIFY_SOURCE gcc compiler
option to automatically detect any such errors.

Feature Test Macros man page describes_FORTIFY_SOURCE as below

"Defining this macro causes some lightweight checks to be performed to
detect some buffer overflow errors when employing various string and memory
manipulation functions (for example, memcpy, memset, stpcpy, strcpy,
strncpy, strcat, strncat, sprintf, snprintf, vsprintf, vsnprintf, gets, and
wide character variants thereof). For some functions, argument consistency
is checked; for example, a check is made that open has been supplied with a
mode argument when the specified flags include O_CREAT. Not all problems
are detected, just some common cases.

If _FORTIFY_SOURCE is set to 1, with compiler optimization level 1 (gcc
-O1) and above, checks that shouldn't change the behavior of conforming
programs are performed.

With _FORTIFY_SOURCE set to 2, some more checking is added, but some
conforming programs might fail.

Some of the checks can be performed at compile time (via macros logic
implemented in header files), and result in compiler warnings; other checks
take place at run time, and result in a run-time error if the check fails.

Use of this macro requires compiler support, available with gcc since
version 4.0."

Fix the buffer overflow error in the check_results() function of the cmt
unit test and enable _FORTIFY_SOURCE gcc check to catch any future buffer
overflow errors.

Reported-by: David Binderman <[email protected]>
Suggested-by: David Binderman <[email protected]>
Tested-by: Babu Moger <[email protected]>
Signed-off-by: Fenghua Yu <[email protected]>
Signed-off-by: Shuah Khan <[email protected]>

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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

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 <[email protected]>
Signed-off-by: Sai Praneeth Prakhya <[email protected]>
Co-developed-by: Babu Moger <[email protected]>
Signed-off-by: Babu Moger <[email protected]>
Signed-off-by: Fenghua Yu <[email protected]>
Signed-off-by: Shuah Khan <[email protected]>

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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 Pranee

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 <[email protected]>
Co-developed-by: Babu Moger <[email protected]>
Signed-off-by: Babu Moger <[email protected]>
Co-developed-by: Fenghua Yu <[email protected]>
Signed-off-by: Fenghua Yu <[email protected]>
Signed-off-by: Shuah Khan <[email protected]>

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