f4f9bda418
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>
33 lines
915 B
C
33 lines
915 B
C
/* SPDX-License-Identifier: GPL-2.0-or-later */
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#ifndef __GUP_TEST_H
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#define __GUP_TEST_H
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#include <linux/types.h>
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#define GUP_FAST_BENCHMARK _IOWR('g', 1, struct gup_test)
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#define PIN_FAST_BENCHMARK _IOWR('g', 2, struct gup_test)
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#define PIN_LONGTERM_BENCHMARK _IOWR('g', 3, struct gup_test)
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#define GUP_BASIC_TEST _IOWR('g', 4, struct gup_test)
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#define PIN_BASIC_TEST _IOWR('g', 5, struct gup_test)
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#define DUMP_USER_PAGES_TEST _IOWR('g', 6, struct gup_test)
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#define GUP_TEST_MAX_PAGES_TO_DUMP 8
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#define GUP_TEST_FLAG_DUMP_PAGES_USE_PIN 0x1
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struct gup_test {
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__u64 get_delta_usec;
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__u64 put_delta_usec;
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__u64 addr;
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__u64 size;
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__u32 nr_pages_per_call;
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__u32 flags;
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/*
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* Each non-zero entry is the number of the page (1-based: first page is
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* page 1, so that zero entries mean "do nothing") from the .addr base.
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*/
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__u32 which_pages[GUP_TEST_MAX_PAGES_TO_DUMP];
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};
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#endif /* __GUP_TEST_H */
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