diff options
| author | John Hubbard <jhubbard@nvidia.com> | 2020-10-13 16:57:04 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-10-13 18:38:34 -0700 |
| commit | 1100262037be8008cc85240389fbe5eac4df034d (patch) | |
| tree | 02931b054859673f933fb7b98db8b71d3b9bd98e /tools | |
| parent | 74c9da4e1dc0ecf70e7fa78568821e3ed8f77938 (diff) | |
selftests/vm: 8x compaction_test speedup
This patch reduces the running time for compaction_test from about 27 sec,
to 3.3 sec, which is about an 8x speedup.
These numbers are for an Intel x86_64 system with 32 GB of DRAM.
The compaction_test.c program was spending most of its time doing mmap(),
1 MB at a time, on about 25 GB of memory.
Instead, do the mmaps 100 MB at a time. (Going past 100 MB doesn't make
things go much faster, because other parts of the program are using the
remaining time.)
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Sri Jayaramappa <sjayaram@akamai.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Link: https://lkml.kernel.org/r/20201002080621.551044-2-jhubbard@nvidia.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/testing/selftests/vm/compaction_test.c | 11 |
1 files changed, 6 insertions, 5 deletions
diff --git a/tools/testing/selftests/vm/compaction_test.c b/tools/testing/selftests/vm/compaction_test.c index bcec71250873..9b420140ba2b 100644 --- a/tools/testing/selftests/vm/compaction_test.c +++ b/tools/testing/selftests/vm/compaction_test.c @@ -18,7 +18,8 @@ #include "../kselftest.h" -#define MAP_SIZE 1048576 +#define MAP_SIZE_MB 100 +#define MAP_SIZE (MAP_SIZE_MB * 1024 * 1024) struct map_list { void *map; @@ -165,7 +166,7 @@ int main(int argc, char **argv) void *map = NULL; unsigned long mem_free = 0; unsigned long hugepage_size = 0; - unsigned long mem_fragmentable = 0; + long mem_fragmentable_MB = 0; if (prereq() != 0) { printf("Either the sysctl compact_unevictable_allowed is not\n" @@ -190,9 +191,9 @@ int main(int argc, char **argv) return -1; } - mem_fragmentable = mem_free * 0.8 / 1024; + mem_fragmentable_MB = mem_free * 0.8 / 1024; - while (mem_fragmentable > 0) { + while (mem_fragmentable_MB > 0) { map = mmap(NULL, MAP_SIZE, PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_PRIVATE | MAP_LOCKED, -1, 0); if (map == MAP_FAILED) @@ -213,7 +214,7 @@ int main(int argc, char **argv) for (i = 0; i < MAP_SIZE; i += page_size) *(unsigned long *)(map + i) = (unsigned long)map + i; - mem_fragmentable--; + mem_fragmentable_MB -= MAP_SIZE_MB; } for (entry = list; entry != NULL; entry = entry->next) { |