foo

1 files changed, 12 insertions, 22 deletions

diff --git a/aio-cancel.c b/aio-cancel.c
index 31cab17..c168224 100644
--- a/aio-cancel.c
+++ b/aio-cancel.c
@@ -27,11 +27,9 @@
 
 #include <libaio.h>
 
-#define PAGE_SIZE	4096UL
-
 static unsigned long canceled = 0, completed = 0;
 
-off_t getsize(int fd)
+static off_t getblocks(int fd)
 {
 	off_t ret;
 	struct stat stat;
@@ -41,15 +39,13 @@ off_t getsize(int fd)
 		exit(EXIT_FAILURE);
 	}
 
-	if (S_ISBLK(stat.st_mode)) {
+	ret = stat.st_size / 512;
+	if (S_ISBLK(stat.st_mode))
 		if (ioctl(fd, BLKGETSIZE, &ret)) {
 			perror("ioctl error");
 			exit(EXIT_FAILURE);
 		}
 
-		ret *= 512;
-	}
-
 	return ret;
 }
 
@@ -72,8 +68,6 @@ static unsigned reap_events(io_context_t io_ctx, unsigned long iosize)
 	struct io_event events[16], *ev;
 	int nr_events = io_getevents(io_ctx, 1, 16, events, NULL);
 
-	//printf("reaped %i events\n", nr_events);
-
 	if (nr_events < 0)
 		die("io_getevents", -nr_events);
 
@@ -95,14 +89,13 @@ static unsigned reap_events(io_context_t io_ctx, unsigned long iosize)
 	return nr_events;
 }
 
-static char buffer[PAGE_SIZE * 4096] __attribute__ ((aligned (PAGE_SIZE)));
-
 int main(int argc, char const *argv[])
 {
 	io_context_t io_ctx;
 	struct stat stat;
 	struct iocb *iocb;
 	struct io_event cancelled;
+	void *buffer;
 	unsigned long nr_ios, iodepth, iosize, in_flight = 0;
 	off_t blocks;
 	int i, ret, fd;
@@ -110,7 +103,7 @@ int main(int argc, char const *argv[])
 	if (argc != 5)
 		usage();
 
-	fd = open(argv[1], O_RDWR | O_DIRECT);
+	fd = open(argv[1], O_RDONLY|O_DIRECT);
 	if (fd < 0) {
 		perror("open");
 		exit(1);
@@ -134,20 +127,17 @@ int main(int argc, char const *argv[])
 		usage();
 	}
 
-	if (iosize % PAGE_SIZE || iosize > sizeof(buffer)) {
-		printf("Bad iosize: must be a multiple of PAGE_SIZE and not more than %zu\n",
-		       sizeof(buffer));
-		exit(EXIT_FAILURE);
-	}
-
-	blocks = getsize(fd);
+	ret = posix_memalign(&buffer, 4096, iosize);
+	if (ret)
+		die("posix_memalign", ret);
 
-	if (blocks < iosize) {
+	blocks = getblocks(fd);
+	if (blocks < iosize / 512) {
 		printf("File too small\n");
 		exit(EXIT_FAILURE);
 	}
 
-	blocks = (blocks - iosize) / PAGE_SIZE;
+	blocks -= iosize / 512;
 
 	printf("Doing %lu random reads to %s with iodepth %lu, iosize %lu\n",
 	       nr_ios, argv[1], iodepth, iosize);
@@ -163,7 +153,7 @@ int main(int argc, char const *argv[])
 
 		iocb = malloc(sizeof(struct iocb));
 		io_prep_pread(iocb, fd, buffer, iosize,
-			      (random() % blocks) * PAGE_SIZE);
+			      (random() % blocks) * 512);
 
 		ret = io_submit(io_ctx, 1, &iocb);
 		if (ret != 1)