[PATCHv2 4/7] tools/gup_benchmark: Allow user specified file

[Keith Busch]

The gup benchmark by default maps anonymous memory. This patch allows a
user to specify a file to map, providing a means to test various
file backings, like device and filesystem DAX.

Cc: Kirill Shutemov <kirill.shute...@linux.intel.com>
Cc: Dave Hansen <dave.han...@intel.com>
Cc: Dan Williams <dan.j.willi...@intel.com>
Signed-off-by: Keith Busch <keith.bu...@intel.com>
---
 tools/testing/selftests/vm/gup_benchmark.c | 19 ++++++++++++++++---
 1 file changed, 16 insertions(+), 3 deletions(-)

diff --git a/tools/testing/selftests/vm/gup_benchmark.c 
b/tools/testing/selftests/vm/gup_benchmark.c
index b2082df8beb4..f2c99e2436f8 100644
--- a/tools/testing/selftests/vm/gup_benchmark.c
+++ b/tools/testing/selftests/vm/gup_benchmark.c
@@ -33,9 +33,12 @@ int main(int argc, char **argv)
        unsigned long size = 128 * MB;
        int i, fd, opt, nr_pages = 1, thp = -1, repeats = 1, write = 0;
        int cmd = GUP_FAST_BENCHMARK;
+       int file_map = -1;
+       int flags = MAP_ANONYMOUS | MAP_PRIVATE;
+       char *file = NULL;
        char *p;
 
-       while ((opt = getopt(argc, argv, "m:r:n:tTLU")) != -1) {
+       while ((opt = getopt(argc, argv, "m:r:n:f:tTLU")) != -1) {
                switch (opt) {
                case 'm':
                        size = atoi(optarg) * MB;
@@ -61,11 +64,22 @@ int main(int argc, char **argv)
                case 'w':
                        write = 1;
                        break;
+               case 'f':
+                       file = optarg;
+                       flags &= ~(MAP_PRIVATE | MAP_ANONYMOUS);
+                       flags |= MAP_SHARED;
+                       break;
                default:
                        return -1;
                }
        }
 
+       if (file) {
+               file_map = open(file, O_RDWR|O_CREAT);
+               if (file_map < 0)
+                       perror("open"), exit(file_map);
+       }
+
        gup.nr_pages_per_call = nr_pages;
        gup.flags = write;
 
@@ -73,8 +87,7 @@ int main(int argc, char **argv)
        if (fd == -1)
                perror("open"), exit(1);
 
-       p = mmap(NULL, size, PROT_READ | PROT_WRITE,
-                       MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
+       p = mmap(NULL, size, PROT_READ | PROT_WRITE, flags, file_map, 0);
        if (p == MAP_FAILED)
                perror("mmap"), exit(1);
        gup.addr = (unsigned long)p;
-- 
2.14.4