Commit 26db3d09 authored by Keith Busch's avatar Keith Busch Committed by Linus Torvalds

mm/gup_benchmark.c: time put_page()

We'd like to measure time to unpin user pages, so this adds a second
benchmark timer on put_page, separate from get_page.

Adding the field breaks this ioctl ABI, but should be okay since this an
in-tree kernel selftest.

[akpm@linux-foundation.org: add expansion to struct gup_benchmark for future use]
Link: http://lkml.kernel.org/r/20181010195605.10689-1-keith.busch@intel.comSigned-off-by: default avatarKeith Busch <keith.busch@intel.com>
Acked-by: default avatarKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 7a1adfdd
......@@ -8,11 +8,13 @@
#define GUP_FAST_BENCHMARK _IOWR('g', 1, struct gup_benchmark)
struct gup_benchmark {
__u64 delta_usec;
__u64 get_delta_usec;
__u64 put_delta_usec;
__u64 addr;
__u64 size;
__u32 nr_pages_per_call;
__u32 flags;
__u64 expansion[10]; /* For future use */
};
static int __gup_benchmark_ioctl(unsigned int cmd,
......@@ -48,14 +50,17 @@ static int __gup_benchmark_ioctl(unsigned int cmd,
}
end_time = ktime_get();
gup->delta_usec = ktime_us_delta(end_time, start_time);
gup->get_delta_usec = ktime_us_delta(end_time, start_time);
gup->size = addr - gup->addr;
start_time = ktime_get();
for (i = 0; i < nr_pages; i++) {
if (!pages[i])
break;
put_page(pages[i]);
}
end_time = ktime_get();
gup->put_delta_usec = ktime_us_delta(end_time, start_time);
kvfree(pages);
return 0;
......
......@@ -17,7 +17,8 @@
#define GUP_FAST_BENCHMARK _IOWR('g', 1, struct gup_benchmark)
struct gup_benchmark {
__u64 delta_usec;
__u64 get_delta_usec;
__u64 put_delta_usec;
__u64 addr;
__u64 size;
__u32 nr_pages_per_call;
......@@ -81,7 +82,8 @@ int main(int argc, char **argv)
if (ioctl(fd, GUP_FAST_BENCHMARK, &gup))
perror("ioctl"), exit(1);
printf("Time: %lld us", gup.delta_usec);
printf("Time: get:%lld put:%lld us", gup.get_delta_usec,
gup.put_delta_usec);
if (gup.size != size)
printf(", truncated (size: %lld)", gup.size);
printf("\n");
......
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