Commit 17de1e559c ("selftests: clarify common error when running
gup_test") had most of its hunks dropped due to a conflict with another
patch accepted into Linux around the same time that implemented the same
behavior as a subset of other changes.
However, the remaining hunk defines the GUP_TEST_FILE macro without
making use of it. This patch makes use of the macro in the two relevant
places.
Furthermore, the above mentioned commit's log message erroneously describes
the changes that were dropped from the patch.
This patch corrects the record.
Fixes: 17de1e559c ("selftests: clarify common error when running gup_test")
Signed-off-by: Joel Savitz <jsavitz@redhat.com>
Reviewed-by: Shuah Khan <skhan@linuxfoundation.org>
Acked-by: Nico Pache <npache@redhat.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
The gup_test binary will fail showing only the output of perror("open") in
the case that /sys/kernel/debug/gup_test is not found. This will almost
always be due to CONFIG_GUP_TEST not being set, which enables
compilation of a kernel that provides this file.
Add a short error message to clarify this failure and point the user to
the solution.
Link: https://lkml.kernel.org/r/20220502224942.995427-1-jsavitz@redhat.com
Signed-off-by: Joel Savitz <jsavitz@redhat.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Nico Pache <npache@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Print three possible reasons /sys/kernel/debug/gup_test cannot be opened
to help users of this test diagnose failures.
Link: https://lkml.kernel.org/r/20220405214809.3351223-1-sidhartha.kumar@oracle.com
Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Reviewed-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
PAGE_SIZE is not 4096 in many configurations, particularly ppc64 uses 64K
pages in majority of cases.
Add helpers to detect PAGE_SIZE and PAGE_SHIFT dynamically.
Without this tests are broken w.r.t reading /proc/self/pagemap
if (pread(pagemap_fd, ent, sizeof(ent),
(uintptr_t)ptr >> (PAGE_SHIFT - 3)) != sizeof(ent))
err(2, "read pagemap");
Link: https://lkml.kernel.org/r/20220307054355.149820-2-aneesh.kumar@linux.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.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>
Patch series "mm/gup: Fix pin page write cache bouncing on has_pinned", v2.
This series contains 3 patches, the 1st one enables threading for
gup_benchmark in the kselftest. The latter two patches are collected from
Andrea's local branch which can fix write cache bouncing issue with
pinning fast-gup.
To be explicit on the latter two patches:
- the 2nd patch fixes the perf degrade when introducing has_pinned, then
- the last patch tries to remove the has_pinned with a bit in mm->flags
For patch 3: originally I think we had a plan to reuse has_pinned into a
counter very soon, however that's not happening at least until today, so
maybe it proves that we can remove it until we really want such a counter
for whatever reason. As the commit message stated, it saves 4 bytes for
each mm without observable regressions.
Regarding testing: we can reference to the commit message of patch 2 for
some detailed testing with will-is-scale. Meanwhile I did patch 1 just
because then we can even easily verify the patchset using the existing
kselftest facilities or even regress test it in the future with the repo
if we want.
Below numbers are extra verification tests that I did besides commit
message of patch 2 using the new gup_benchmark and 256 cpus. Below test
is done on 40 cpus host with Intel(R) Xeon(R) CPU E5-2630 v4 @ 2.20GHz,
and I can get similar result (of course the write cache bouncing get
severe with even more cores).
After patch 1 applied (only test patch, so using old kernel):
$ sudo chrt -f 1 ./gup_test -a -m 512 -j 40
PIN_FAST_BENCHMARK: Time: get:459632 put:5990 us
PIN_FAST_BENCHMARK: Time: get:461967 put:5840 us
PIN_FAST_BENCHMARK: Time: get:464521 put:6140 us
PIN_FAST_BENCHMARK: Time: get:465176 put:7100 us
PIN_FAST_BENCHMARK: Time: get:465960 put:6733 us
PIN_FAST_BENCHMARK: Time: get:465324 put:6781 us
PIN_FAST_BENCHMARK: Time: get:466018 put:7130 us
PIN_FAST_BENCHMARK: Time: get:466362 put:7118 us
PIN_FAST_BENCHMARK: Time: get:465118 put:6975 us
PIN_FAST_BENCHMARK: Time: get:466422 put:6602 us
PIN_FAST_BENCHMARK: Time: get:465791 put:6818 us
PIN_FAST_BENCHMARK: Time: get:467091 put:6298 us
PIN_FAST_BENCHMARK: Time: get:467694 put:5432 us
PIN_FAST_BENCHMARK: Time: get:469575 put:5581 us
PIN_FAST_BENCHMARK: Time: get:468124 put:6055 us
PIN_FAST_BENCHMARK: Time: get:468877 put:6720 us
PIN_FAST_BENCHMARK: Time: get:467212 put:4961 us
PIN_FAST_BENCHMARK: Time: get:467834 put:6697 us
PIN_FAST_BENCHMARK: Time: get:470778 put:6398 us
PIN_FAST_BENCHMARK: Time: get:469788 put:6310 us
PIN_FAST_BENCHMARK: Time: get:488277 put:7113 us
PIN_FAST_BENCHMARK: Time: get:486613 put:7085 us
PIN_FAST_BENCHMARK: Time: get:486940 put:7202 us
PIN_FAST_BENCHMARK: Time: get:488728 put:7101 us
PIN_FAST_BENCHMARK: Time: get:487570 put:7327 us
PIN_FAST_BENCHMARK: Time: get:489260 put:7027 us
PIN_FAST_BENCHMARK: Time: get:488846 put:6866 us
PIN_FAST_BENCHMARK: Time: get:488521 put:6745 us
PIN_FAST_BENCHMARK: Time: get:489950 put:6459 us
PIN_FAST_BENCHMARK: Time: get:489777 put:6617 us
PIN_FAST_BENCHMARK: Time: get:488224 put:6591 us
PIN_FAST_BENCHMARK: Time: get:488644 put:6477 us
PIN_FAST_BENCHMARK: Time: get:488754 put:6711 us
PIN_FAST_BENCHMARK: Time: get:488875 put:6743 us
PIN_FAST_BENCHMARK: Time: get:489290 put:6657 us
PIN_FAST_BENCHMARK: Time: get:490264 put:6684 us
PIN_FAST_BENCHMARK: Time: get:489631 put:6737 us
PIN_FAST_BENCHMARK: Time: get:488434 put:6655 us
PIN_FAST_BENCHMARK: Time: get:492213 put:6297 us
PIN_FAST_BENCHMARK: Time: get:491124 put:6173 us
After the whole series applied (new fixed kernel):
$ sudo chrt -f 1 ./gup_test -a -m 512 -j 40
PIN_FAST_BENCHMARK: Time: get:82038 put:7041 us
PIN_FAST_BENCHMARK: Time: get:82144 put:6817 us
PIN_FAST_BENCHMARK: Time: get:83417 put:6674 us
PIN_FAST_BENCHMARK: Time: get:82540 put:6594 us
PIN_FAST_BENCHMARK: Time: get:83214 put:6681 us
PIN_FAST_BENCHMARK: Time: get:83444 put:6889 us
PIN_FAST_BENCHMARK: Time: get:83194 put:7499 us
PIN_FAST_BENCHMARK: Time: get:84876 put:7369 us
PIN_FAST_BENCHMARK: Time: get:86092 put:10289 us
PIN_FAST_BENCHMARK: Time: get:86153 put:10415 us
PIN_FAST_BENCHMARK: Time: get:85026 put:7751 us
PIN_FAST_BENCHMARK: Time: get:85458 put:7944 us
PIN_FAST_BENCHMARK: Time: get:85735 put:8154 us
PIN_FAST_BENCHMARK: Time: get:85851 put:8299 us
PIN_FAST_BENCHMARK: Time: get:86323 put:9617 us
PIN_FAST_BENCHMARK: Time: get:86288 put:10496 us
PIN_FAST_BENCHMARK: Time: get:87697 put:9346 us
PIN_FAST_BENCHMARK: Time: get:87980 put:8382 us
PIN_FAST_BENCHMARK: Time: get:88719 put:8400 us
PIN_FAST_BENCHMARK: Time: get:87616 put:8588 us
PIN_FAST_BENCHMARK: Time: get:86730 put:9563 us
PIN_FAST_BENCHMARK: Time: get:88167 put:8673 us
PIN_FAST_BENCHMARK: Time: get:86844 put:9777 us
PIN_FAST_BENCHMARK: Time: get:88068 put:11774 us
PIN_FAST_BENCHMARK: Time: get:86170 put:15676 us
PIN_FAST_BENCHMARK: Time: get:87967 put:12827 us
PIN_FAST_BENCHMARK: Time: get:95773 put:7652 us
PIN_FAST_BENCHMARK: Time: get:87734 put:13650 us
PIN_FAST_BENCHMARK: Time: get:89833 put:14237 us
PIN_FAST_BENCHMARK: Time: get:96186 put:8029 us
PIN_FAST_BENCHMARK: Time: get:95532 put:8886 us
PIN_FAST_BENCHMARK: Time: get:95351 put:5826 us
PIN_FAST_BENCHMARK: Time: get:96401 put:8407 us
PIN_FAST_BENCHMARK: Time: get:96473 put:8287 us
PIN_FAST_BENCHMARK: Time: get:97177 put:8430 us
PIN_FAST_BENCHMARK: Time: get:98120 put:5263 us
PIN_FAST_BENCHMARK: Time: get:96271 put:7757 us
PIN_FAST_BENCHMARK: Time: get:99628 put:10467 us
PIN_FAST_BENCHMARK: Time: get:99344 put:10045 us
PIN_FAST_BENCHMARK: Time: get:94212 put:15485 us
Summary:
Old kernel: 477729.97 (+-3.79%)
New kernel: 89144.65 (+-11.76%)
This patch (of 3):
Add a new parameter "-j N" to support concurrent gup test.
Link: https://lkml.kernel.org/r/20210507150553.208763-1-peterx@redhat.com
Link: https://lkml.kernel.org/r/20210507150553.208763-2-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Cc: Kirill Shutemov <kirill@shutemov.name>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When pages are pinned they can be faulted in userland and migrated, and
they can be faulted right in kernel without migration.
In either case, the pinned pages must end-up being pinnable (not
movable).
Add a new test to gup_test, to help verify that the gup/pup
(get_user_pages() / pin_user_pages()) behavior with respect to pinnable
and movable pages is reasonable and correct. Specifically, provide a
way to:
1) Verify that only "pinnable" pages are pinned. This is checked
automatically for you.
2) Verify that gup/pup performance is reasonable. This requires
comparing benchmarks between doing gup/pup on pages that have been
pre-faulted in from user space, vs. doing gup/pup on pages that are
not faulted in until gup/pup time (via FOLL_TOUCH). This decision is
controlled with the new -z command line option.
Link: https://lkml.kernel.org/r/20210215161349.246722-15-pasha.tatashin@soleen.com
Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: James Morris <jmorris@namei.org>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sasha Levin <sashal@kernel.org>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Tyler Hicks <tyhicks@linux.microsoft.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In gup_test both gup_flags and test_flags use the same flags field.
This is broken.
Farther, in the actual gup_test.c all the passed gup_flags are erased
and unconditionally replaced with FOLL_WRITE.
Which means that test_flags are ignored, and code like this always
performs pin dump test:
155 if (gup->flags & GUP_TEST_FLAG_DUMP_PAGES_USE_PIN)
156 nr = pin_user_pages(addr, nr, gup->flags,
157 pages + i, NULL);
158 else
159 nr = get_user_pages(addr, nr, gup->flags,
160 pages + i, NULL);
161 break;
Add a new test_flags field, to allow raw gup_flags to work. Add a new
subcommand for DUMP_USER_PAGES_TEST to specify that pin test should be
performed.
Remove unconditional overwriting of gup_flags via FOLL_WRITE. But,
preserve the previous behaviour where FOLL_WRITE was the default flag,
and add a new option "-W" to unset FOLL_WRITE.
Rename flags with gup_flags.
With the fix, dump works like this:
root@virtme:/# gup_test -c
---- page #0, starting from user virt addr: 0x7f8acb9e4000
page:00000000d3d2ee27 refcount:2 mapcount:1 mapping:0000000000000000
index:0x0 pfn:0x100bcf
anon flags: 0x300000000080016(referenced|uptodate|lru|swapbacked)
raw: 0300000000080016 ffffd0e204021608 ffffd0e208df2e88 ffff8ea04243ec61
raw: 0000000000000000 0000000000000000 0000000200000000 0000000000000000
page dumped because: gup_test: dump_pages() test
DUMP_USER_PAGES_TEST: done
root@virtme:/# gup_test -c -p
---- page #0, starting from user virt addr: 0x7fd19701b000
page:00000000baed3c7d refcount:1025 mapcount:1 mapping:0000000000000000
index:0x0 pfn:0x108008
anon flags: 0x300000000080014(uptodate|lru|swapbacked)
raw: 0300000000080014 ffffd0e204200188 ffffd0e205e09088 ffff8ea04243ee71
raw: 0000000000000000 0000000000000000 0000040100000000 0000000000000000
page dumped because: gup_test: dump_pages() test
DUMP_USER_PAGES_TEST: done
Refcount shows the difference between pin vs no-pin case.
Also change type of nr from int to long, as it counts number of pages.
Link: https://lkml.kernel.org/r/20210215161349.246722-14-pasha.tatashin@soleen.com
Signed-off-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: James Morris <jmorris@namei.org>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sasha Levin <sashal@kernel.org>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Tyler Hicks <tyhicks@linux.microsoft.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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>
Therefore, some minor cleanup and improvements are in order:
1. Rename the other items appropriately.
2. Stop reporting timing information on the non-benchmark items. It's
still being recorded and is available, but there's no point in
cluttering up the report with data that no one reasonably needs to
check.
3. Don't do iterations, for non-benchmark items.
4. Print out a shorter, more appropriate report for the non-benchmark
tests.
5. Add the command that was run, to the report. This really helps, as
there are quite a lot of options now.
6. Use a larger integer type for cmd, now that it's being compared
Otherwise it doesn't work, because in this case cmd is about 3 billion,
which is the perfect size for problems with signed vs unsigned int.
Link: https://lkml.kernel.org/r/20201026064021.3545418-6-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>
A few cleanups that don't deserve separate patches, but that also should
not clutter up other functional changes:
1. Remove an unnecessary #include <prctl.h>
2. Restore the sorted order of TEST_GEN_FILES.
3. Add -lpthread to the common LDLIBS, as it is harmless and several
tests use it. This gets rid of one special rule already.
Link: https://lkml.kernel.org/r/20201026064021.3545418-5-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>
Avoid the need to copy-paste the gup_test ioctl commands and the struct
gup_test definition, between the kernel and the user space application, by
providing a new header file for these. This allows easier and safer
adding of new ioctl calls, as well as reducing the overall line count.
Details: The header file has to be able to compile independently, because
of the arguably unfortunate way that the Makefile is written: the Makefile
tries to build all of its prerequisites, when really it should be only
building the .c files, and leaving the other prerequisites (LOCAL_HDRS) as
pure dependencies.
That Makefile limitation is probably not worth fixing, but it explains why
one of the includes had to be moved into the new header file.
Also: simplify the ioctl struct (struct gup_test), by deleting the unused
__expansion[10] field. This sort of thing is what you might see in a
stable ABI, but this low-level, kernel-developer-oriented selftests/vm
system is very much not subject to ABI stability. So "expansion" and
"reserved" fields are unnecessary here.
Link: https://lkml.kernel.org/r/20201026064021.3545418-3-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>
Patch series "selftests/vm: gup_test, hmm-tests, assorted improvements", v3.
Summary: This series provides two main things, and a number of smaller
supporting goodies. The two main points are:
1) Add a new sub-test to gup_test, which in turn is a renamed version
of gup_benchmark. This sub-test allows nicer testing of dump_pages(),
at least on user-space pages.
For quite a while, I was doing a quick hack to gup_test.c whenever I
wanted to try out changes to dump_page(). Then Matthew Wilcox asked me
what I meant when I said "I used my dump_page() unit test", and I
realized that it might be nice to check in a polished up version of
that.
Details about how it works and how to use it are in the commit
description for patch #6 ("selftests/vm: gup_test: introduce the
dump_pages() sub-test").
2) Fixes a limitation of hmm-tests: these tests are incredibly useful,
but only if people actually build and run them. And it turns out that
libhugetlbfs is a little too effective at throwing a wrench in the
works, there. So I've added a little configuration check that removes
just two of the 21 hmm-tests, if libhugetlbfs is not available.
Further details in the commit description of patch #8
("selftests/vm: hmm-tests: remove the libhugetlbfs dependency").
Other smaller things that this series does:
a) Remove code duplication by creating gup_test.h.
b) Clear up the sub-test organization, and their invocation within
run_vmtests.sh.
c) Other minor assorted improvements.
[1] v2 is here:
https://lore.kernel.org/linux-doc/20200929212747.251804-1-jhubbard@nvidia.com/
[2] https://lore.kernel.org/r/CAHk-=wgh-TMPHLY3jueHX7Y2fWh3D+nMBqVS__AZm6-oorquWA@mail.gmail.com
This patch (of 9):
Rename nearly every "gup_benchmark" reference and file name to "gup_test".
The one exception is for the actual gup benchmark test itself.
The current code already does a *little* bit more than benchmarking, and
definitely covers more than get_user_pages_fast(). More importantly,
however, subsequent patches are about to add some functionality that is
non-benchmark related.
Closely related changes:
* Kconfig: in addition to renaming the options from GUP_BENCHMARK to
GUP_TEST, update the help text to reflect that it's no longer a
benchmark-only test.
Link: https://lkml.kernel.org/r/20201026064021.3545418-1-jhubbard@nvidia.com
Link: https://lkml.kernel.org/r/20201026064021.3545418-2-jhubbard@nvidia.com
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Jérôme Glisse <jglisse@redhat.com>
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>
2020-12-15 12:13:38 -08:00
Renamed from tools/testing/selftests/vm/gup_benchmark.c (Browse further)
