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| author | John Hubbard <jhubbard@nvidia.com> | 2020-12-15 04:05:21 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-12-15 21:13:38 +0100 |
| commit | f4f9bda418ab8b4dbc5372e9e2a28162f7777154 (patch) | |
| tree | 1e4cb5f83f338a2bd249a92b55280d2c3e536add /mm/Kconfig | |
| parent | selftests/vm: only some gup_test items are really benchmarks (diff) | |
| download | linux-f4f9bda418ab8b4dbc5372e9e2a28162f7777154.tar.xz linux-f4f9bda418ab8b4dbc5372e9e2a28162f7777154.zip | |
selftests/vm: gup_test: introduce the dump_pages() sub-test
For quite a while, I was doing a quick hack to gup_test.c (previously,
gup_benchmark.c) whenever I wanted to try out my changes to dump_page().
This makes that hack unnecessary, and instead allows anyone to easily get
the same coverage from a user space program. That saves a lot of time
because you don't have to change the kernel, in order to test different
pages and options.
The new sub-test takes advantage of the existing gup_test infrastructure,
which already provides a simple user space program, some allocated user
space pages, an ioctl call, pinning of those pages (via either
get_user_pages or pin_user_pages) and a corresponding kernel-side test
invocation. There's not much more required, mainly just a couple of
inputs from the user.
In fact, the new test re-uses the existing command line options in order
to get various helpful combinations (THP or normal, _fast or slow gup, gup
vs. pup, and more).
New command line options are: which pages to dump, and what type of
"get/pin" to use.
In order to figure out which pages to dump, the logic is:
* If the user doesn't specify anything, the page 0 (the first page in
the address range that the program sets up for testing) is dumped.
* Or, the user can type up to 8 page indices anywhere on the command
line. If you type more than 8, then it uses the first 8 and ignores the
remaining items.
For example:
./gup_test -ct -F 1 0 19 0x1000
Meaning:
-c: dump pages sub-test
-t: use THP pages
-F 1: use pin_user_pages() instead of get_user_pages()
0 19 0x1000: dump pages 0, 19, and 4096
Link: https://lkml.kernel.org/r/20201026064021.3545418-7-jhubbard@nvidia.com
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/Kconfig')
| -rw-r--r-- | mm/Kconfig | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/mm/Kconfig b/mm/Kconfig index e25e5cb2989f..350f2e23a94a 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -832,6 +832,12 @@ config GUP_TEST get_user_pages*() and pin_user_pages*(), as well as smoke tests of the non-_fast variants. + There is also a sub-test that allows running dump_page() on any + of up to eight pages (selected by command line args) within the + range of user-space addresses. These pages are either pinned via + pin_user_pages*(), or pinned via get_user_pages*(), as specified + by other command line arguments. + See tools/testing/selftests/vm/gup_test.c config GUP_GET_PTE_LOW_HIGH |