igt/gem_pread: Support to verify pread/pwrite for non-shmem backed obj

This patch adds support to verify pread/pwrite for non-shmem backed
objects. It also shows the pread/pwrite speed.
It also tests speeds for pread with and without user side page faults

v2: Fixed Rebase conflicts (Ankit)

v3: Precalculating values to avoid redundant function calls (Dave)
Replaced igt_subtest by igt_subtest_f, added asserts for mmap, corrected
indentation (Tvrtko)

v4: Updated data types to avoid redundant type conversions (Tvrtko)
Corrected pagefault-pread time calculation (Ankit)

Signed-off-by: Ankitprasad Sharma <ankitprasad.r.sharma@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Signed-off-by: Thomas Wood <thomas.wood@intel.com>

tests/gem_pread.c

@@ -40,6 +40,10 @@
 #include "drm.h"
 
 #define OBJECT_SIZE 16384
+#define LARGE_OBJECT_SIZE 1024 * 1024
+#define KGRN "\x1B[32m"
+#define KRED "\x1B[31m"
+#define KNRM "\x1B[0m"
 
 static void do_gem_read(int fd, uint32_t handle, void *buf, int len, int loops)
 {
@@ -75,12 +79,16 @@ static const char *bytes_per_sec(char *buf, double v)
 
 
 uint32_t *src, dst;
+uint32_t *dst_user, src_stolen, large_stolen;
+uint32_t *stolen_pf_user, *stolen_nopf_user;
 int fd, count;
 
 int main(int argc, char **argv)
 {
 	int object_size = 0;
-	uint32_t buf[20];
+	double usecs;
+	char buf[100];
+	char* bps;
 	const struct {
 		int level;
 		const char *name;
@@ -105,6 +113,8 @@ int main(int argc, char **argv)
 
 		dst = gem_create(fd, object_size);
 		src = malloc(object_size);
+		src_stolen = gem_create_stolen(fd, object_size);
+		dst_user = malloc(object_size);
 	}
 
 	igt_subtest("basic") {
@@ -114,10 +124,10 @@ int main(int argc, char **argv)
 			gettimeofday(&start, NULL);
 			do_gem_read(fd, dst, src, object_size, count);
 			gettimeofday(&end, NULL);
+			usecs = elapsed(&start, &end, count);
+			bps = bytes_per_sec(buf, object_size/usecs*1e6);
 			igt_info("Time to pread %d bytes x %6d:	%7.3fµs, %s\n",
-				 object_size, count,
+				 object_size, count, usecs, bps);
-				 elapsed(&start, &end, count),
-				 bytes_per_sec((char *)buf, object_size/elapsed(&start, &end, count)*1e6));
 			fflush(stdout);
 		}
 	}
@@ -132,18 +142,102 @@ int main(int argc, char **argv)
 				gettimeofday(&start, NULL);
 				do_gem_read(fd, dst, src, object_size, count);
 				gettimeofday(&end, NULL);
+				usecs = elapsed(&start, &end, count);
+				bps = bytes_per_sec(buf, object_size/usecs*1e6);
 				igt_info("Time to %s pread %d bytes x %6d:	%7.3fµs, %s\n",
-					 c->name, object_size, count,
+					 c->name, object_size, count, usecs, bps);
-					 elapsed(&start, &end, count),
-					 bytes_per_sec((char *)buf, object_size/elapsed(&start, &end, count)*1e6));
 				fflush(stdout);
 			}
 		}
 	}
 
+	igt_subtest("stolen-normal") {
+		for (count = 1; count <= 1<<17; count <<= 1) {
+			struct timeval start, end;
+
+			gettimeofday(&start, NULL);
+			do_gem_read(fd, src_stolen, dst_user, object_size, count);
+			gettimeofday(&end, NULL);
+			usecs = elapsed(&start, &end, count);
+			bps = bytes_per_sec(buf, object_size/usecs*1e6);
+			igt_info("Time to pread %d bytes x %6d:	%7.3fµs, %s\n",
+				 object_size, count, usecs, bps);
+			fflush(stdout);
+		}
+	}
+	for (c = cache; c->level != -1; c++) {
+		igt_subtest_f("stolen-%s", c->name) {
+			gem_set_caching(fd, src_stolen, c->level);
+
+			for (count = 1; count <= 1<<17; count <<= 1) {
+				struct timeval start, end;
+
+				gettimeofday(&start, NULL);
+				do_gem_read(fd, src_stolen, dst_user,
+					    object_size, count);
+				gettimeofday(&end, NULL);
+				usecs = elapsed(&start, &end, count);
+				bps = bytes_per_sec(buf, object_size/usecs*1e6);
+				igt_info("Time to stolen-%s pread %d bytes x %6d:      %7.3fµs, %s\n",
+					 c->name, object_size, count, usecs, bps);
+				fflush(stdout);
+			}
+		}
+	}
+
+	/* List the time taken in pread operation for stolen objects, with
+	 * and without the overhead of page fault handling on accessing the
+	 * user space buffer
+	 */
+	igt_subtest("pagefault-pread") {
+		large_stolen = gem_create_stolen(fd, LARGE_OBJECT_SIZE);
+		stolen_nopf_user = (uint32_t *) mmap(NULL, LARGE_OBJECT_SIZE,
+						PROT_WRITE,
+						MAP_ANONYMOUS|MAP_PRIVATE,
+						-1, 0);
+		igt_assert(stolen_nopf_user);
+
+		for (count = 1; count <= 10; count ++) {
+			struct timeval start, end;
+			double t_elapsed = 0;
+
+			gettimeofday(&start, NULL);
+			do_gem_read(fd, large_stolen, stolen_nopf_user,
+				    LARGE_OBJECT_SIZE, 1);
+			gettimeofday(&end, NULL);
+			t_elapsed = elapsed(&start, &end, count);
+			bps = bytes_per_sec(buf, object_size/t_elapsed*1e6);
+			igt_info("Pagefault-N - Time to pread %d bytes: %7.3fµs, %s\n",
+				 LARGE_OBJECT_SIZE, t_elapsed, bps);
+
+			stolen_pf_user = (uint32_t *) mmap(NULL, LARGE_OBJECT_SIZE,
+						      PROT_WRITE,
+						      MAP_ANONYMOUS|MAP_PRIVATE,
+						      -1, 0);
+			igt_assert(stolen_pf_user);
+
+			gettimeofday(&start, NULL);
+			do_gem_read(fd, large_stolen, stolen_pf_user,
+				    LARGE_OBJECT_SIZE, 1);
+			gettimeofday(&end, NULL);
+			usecs = elapsed(&start, &end, count);
+			bps = bytes_per_sec(buf, object_size/usecs*1e6);
+			igt_info("Pagefault-Y - Time to pread %d bytes: %7.3fµs, %s%s%s\n",
+				 LARGE_OBJECT_SIZE, usecs,
+				 t_elapsed < usecs ? KGRN : KRED, bps, KNRM);
+			fflush(stdout);
+			munmap(stolen_pf_user, LARGE_OBJECT_SIZE);
+		}
+		munmap(stolen_nopf_user, LARGE_OBJECT_SIZE);
+		gem_close(fd, large_stolen);
+	}
+
+
 	igt_fixture {
 		free(src);
 		gem_close(fd, dst);
+		free(dst_user);
+		gem_close(fd, src_stolen);
 
 		close(fd);
 	}

tests/gem_pwrite.c

@@ -132,12 +132,15 @@ static void test_big_gtt(int fd, int scale)
 }
 
 uint32_t *src, dst;
+uint32_t *src_user, dst_stolen;
 int fd;
 
 int main(int argc, char **argv)
 {
 	int object_size = 0;
-	uint32_t buf[20];
+	double usecs;
+	char* bps;
+	char buf[100];
 	int count;
 	const struct {
 		int level;
@@ -164,6 +167,8 @@ int main(int argc, char **argv)
 
 		dst = gem_create(fd, object_size);
 		src = malloc(object_size);
+		dst_stolen = gem_create_stolen(fd, object_size);
+		src_user = malloc(object_size);
 	}
 
 	igt_subtest("basic") {
@@ -173,10 +178,10 @@ int main(int argc, char **argv)
 			gettimeofday(&start, NULL);
 			do_gem_write(fd, dst, src, object_size, count);
 			gettimeofday(&end, NULL);
+			usecs = elapsed(&start, &end, count);
+			bps = bytes_per_sec(buf, object_size/usecs*1e6);
 			igt_info("Time to pwrite %d bytes x %6d:	%7.3fµs, %s\n",
-				 object_size, count,
+				 object_size, count, usecs, bps);
-				 elapsed(&start, &end, count),
-				 bytes_per_sec((char *)buf, object_size/elapsed(&start, &end, count)*1e6));
 			fflush(stdout);
 		}
 	}
@@ -191,10 +196,46 @@ int main(int argc, char **argv)
 				gettimeofday(&start, NULL);
 				do_gem_write(fd, dst, src, object_size, count);
 				gettimeofday(&end, NULL);
+				usecs = elapsed(&start, &end, count);
+				bps = bytes_per_sec(buf, object_size/usecs*1e6);
 				igt_info("Time to %s pwrite %d bytes x %6d:	%7.3fµs, %s\n",
+					 c->name, object_size, count, usecs, bps);
+				fflush(stdout);
+			}
+		}
+	}
+
+	igt_subtest("stolen-normal") {
+		for (count = 1; count <= 1<<17; count <<= 1) {
+			struct timeval start, end;
+
+			gettimeofday(&start, NULL);
+			do_gem_write(fd, dst_stolen, src_user,
+				     object_size, count);
+			gettimeofday(&end, NULL);
+			usecs = elapsed(&start, &end, count);
+			bps = bytes_per_sec(buf, object_size/usecs*1e6);
+			igt_info("Time to pwrite %d bytes x %6d:        %7.3fµs, %s\n",
+				 object_size, count, usecs, bps);
+			fflush(stdout);
+		}
+	}
+
+	for (c = cache; c->level != -1; c++) {
+		igt_subtest_f("stolen-%s", c->name) {
+			gem_set_caching(fd, dst, c->level);
+			for (count = 1; count <= 1<<17; count <<= 1) {
+				struct timeval start, end;
+
+				gettimeofday(&start, NULL);
+				do_gem_write(fd, dst_stolen, src_user,
+					     object_size, count);
+				gettimeofday(&end, NULL);
+				bps = bytes_per_sec(buf,
+						    object_size/usecs*1e6);
+				igt_info("Time to stolen-%s pwrite %d bytes x %6d:     %7.3fµs, %s\n",
 					 c->name, object_size, count,
-					 elapsed(&start, &end, count),
+					 usecs, bps);
-					 bytes_per_sec((char *)buf, object_size/elapsed(&start, &end, count)*1e6));
 				fflush(stdout);
 			}
 		}
@@ -203,6 +244,8 @@ int main(int argc, char **argv)
 	igt_fixture {
 		free(src);
 		gem_close(fd, dst);
+		free(src_user);
+		gem_close(fd, dst_stolen);
 	}
 
 	igt_subtest("big-cpu")