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Uladzislau Rezki (Sony) 3f21a6b7ef vmalloc: add test driver to analyse vmalloc allocator
This adds a new kernel module for analysis of vmalloc allocator.  It is
only enabled as a module.  There are two main reasons this module should
be used for: performance evaluation and stressing of vmalloc subsystem.

It consists of several test cases.  As of now there are 8.  The module
has five parameters we can specify to change its the behaviour.

1) run_test_mask - set of tests to be run

id: 1,   name: fix_size_alloc_test
id: 2,   name: full_fit_alloc_test
id: 4,   name: long_busy_list_alloc_test
id: 8,   name: random_size_alloc_test
id: 16,  name: fix_align_alloc_test
id: 32,  name: random_size_align_alloc_test
id: 64,  name: align_shift_alloc_test
id: 128, name: pcpu_alloc_test

By default all tests are in run test mask.  If you want to select some
specific tests it is possible to pass the mask.  For example for first,
second and fourth tests we go 11 value.

2) test_repeat_count - how many times each test should be repeated
By default it is one time per test. It is possible to pass any number.
As high the value is the test duration gets increased.

3) test_loop_count - internal test loop counter. By default it is set
to 1000000.

4) single_cpu_test - use one CPU to run the tests
By default this parameter is set to false. It means that all online
CPUs execute tests. By setting it to 1, the tests are executed by
first online CPU only.

5) sequential_test_order - run tests in sequential order
By default this parameter is set to false. It means that before running
tests the order is shuffled. It is possible to make it sequential, just
set it to 1.

Performance analysis:
In order to evaluate performance of vmalloc allocations, usually it
makes sense to use only one CPU that runs tests, use sequential order,
number of repeat tests can be different as well as set of test mask.

For example if we want to run all tests, to use one CPU and repeat each
test 3 times. Insert the module passing following parameters:

single_cpu_test=1 sequential_test_order=1 test_repeat_count=3

with following output:

<snip>
Summary: fix_size_alloc_test passed: 3 failed: 0 repeat: 3 loops: 1000000 avg: 901177 usec
Summary: full_fit_alloc_test passed: 3 failed: 0 repeat: 3 loops: 1000000 avg: 1039341 usec
Summary: long_busy_list_alloc_test passed: 3 failed: 0 repeat: 3 loops: 1000000 avg: 11775763 usec
Summary: random_size_alloc_test passed 3: failed: 0 repeat: 3 loops: 1000000 avg: 6081992 usec
Summary: fix_align_alloc_test passed: 3 failed: 0 repeat: 3, loops: 1000000 avg: 2003712 usec
Summary: random_size_align_alloc_test passed: 3 failed: 0 repeat: 3 loops: 1000000 avg: 2895689 usec
Summary: align_shift_alloc_test passed: 0 failed: 3 repeat: 3 loops: 1000000 avg: 573 usec
Summary: pcpu_alloc_test passed: 3 failed: 0 repeat: 3 loops: 1000000 avg: 95802 usec
All test took CPU0=192945605995 cycles
<snip>

The align_shift_alloc_test is expected to be failed.

Stressing:
In order to stress the vmalloc subsystem we run all available test cases
on all available CPUs simultaneously. In order to prevent constant behaviour
pattern, the test cases array is shuffled by default to randomize the order
of test execution.

For example if we want to run all tests(default), use all online CPUs(default)
with shuffled order(default) and to repeat each test 30 times. The command
would be like:

modprobe vmalloc_test test_repeat_count=30

Expected results are the system is alive, there are no any BUG_ONs or Kernel
Panics the tests are completed, no memory leaks.

[urezki@gmail.com: fix 32-bit builds]
  Link: http://lkml.kernel.org/r/20190106214839.ffvjvmrn52uqog7k@pc636
[urezki@gmail.com: make CONFIG_TEST_VMALLOC depend on CONFIG_MMU]
  Link: http://lkml.kernel.org/r/20190219085441.s6bg2gpy4esny5vw@pc636
Link: http://lkml.kernel.org/r/20190103142108.20744-3-urezki@gmail.com
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-03-05 21:07:15 -08:00
arch mm: replace all open encodings for NUMA_NO_NODE 2019-03-05 21:07:14 -08:00
block for-linus-20190215 2019-02-15 09:12:28 -08:00
certs kbuild: remove redundant target cleaning on failure 2019-01-06 09:46:51 +09:00
crypto Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2019-03-05 09:09:55 -08:00
Documentation mm: convert PG_balloon to PG_offline 2019-03-05 21:07:14 -08:00
drivers mm: replace all open encodings for NUMA_NO_NODE 2019-03-05 21:07:14 -08:00
firmware kbuild: change filechk to surround the given command with { } 2019-01-06 09:46:51 +09:00
fs memcg: localize memcg_kmem_enabled() check 2019-03-05 21:07:15 -08:00
include memcg: localize memcg_kmem_enabled() check 2019-03-05 21:07:15 -08:00
init mm: replace all open encodings for NUMA_NO_NODE 2019-03-05 21:07:14 -08:00
ipc ipc: introduce ksys_ipc()/compat_ksys_ipc() for s390 2019-01-18 09:33:18 +01:00
kernel mm: replace all open encodings for NUMA_NO_NODE 2019-03-05 21:07:14 -08:00
lib vmalloc: add test driver to analyse vmalloc allocator 2019-03-05 21:07:15 -08:00
LICENSES This is a fairly typical cycle for documentation. There's some welcome 2018-10-24 18:01:11 +01:00
mm vmalloc: export __vmalloc_node_range for CONFIG_TEST_VMALLOC_MODULE 2019-03-05 21:07:15 -08:00
net mm: replace all open encodings for NUMA_NO_NODE 2019-03-05 21:07:14 -08:00
samples Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2019-03-05 08:26:13 -08:00
scripts scripts/decode_stacktrace.sh: handle RIP address with segment 2019-03-05 21:07:13 -08:00
security get rid of legacy 'get_ds()' function 2019-03-04 10:50:14 -08:00
sound sound fixes for 5.0 2019-02-20 09:42:52 -08:00
tools tools/: replace open encodings for NUMA_NO_NODE 2019-03-05 21:07:14 -08:00
usr user/Makefile: Fix typo and capitalization in comment section 2018-12-11 00:18:03 +09:00
virt kvm: properly check debugfs dentry before using it 2019-02-28 08:57:32 -08:00
.clang-format clang-format: Update .clang-format with the latest for_each macro list 2019-01-19 19:26:06 +01:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore Add hch to .get_maintainer.ignore 2015-08-21 14:30:10 -07:00
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore kbuild: Add support for DT binding schema checks 2018-12-13 09:41:32 -06:00
.mailmap .mailmap: Add Mathieu Othacehe 2019-02-21 11:41:19 +00:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS CREDITS/MAINTAINERS: Retire parisc-linux.org email domain 2019-02-21 20:16:10 +01:00
Kbuild kbuild: use assignment instead of define ... endef for filechk_* rules 2019-01-06 10:22:35 +09:00
Kconfig kconfig: move the "Executable file formats" menu to fs/Kconfig.binfmt 2018-08-02 08:06:55 +09:00
MAINTAINERS Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2019-03-05 09:09:55 -08:00
Makefile Linux 5.0 2019-03-03 15:21:29 -08:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.