t/io_uring: make more efficient for multiple files

Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/t/io_uring.c b/t/io_uring.c
index 39332c8e6cdc09df0e7ae769bec86059ee6c8a12..1c0d1535ef041facbd511a72b752a493a1cdf205 100644 (file)
--- a/t/io_uring.c
+++ b/t/io_uring.c
@@ -44,10 +44,10 @@ struct io_cq_ring {
        struct io_uring_cqe *cqes;
 };
 
-#define DEPTH                  32
+#define DEPTH                  128
 
-#define BATCH_SUBMIT           8
-#define BATCH_COMPLETE         8
+#define BATCH_SUBMIT           64
+#define BATCH_COMPLETE         64
 
 #define BS                     4096
 
@@ -57,6 +57,7 @@ static unsigned sq_ring_mask, cq_ring_mask;
 
 struct file {
        unsigned long max_blocks;
+       unsigned pending_ios;
        int fd;
 };
 
@@ -74,6 +75,7 @@ struct submitter {
        unsigned long calls;
        unsigned long cachehit, cachemiss;
        volatile int finish;
+
        struct file files[MAX_FDS];
        unsigned nr_files;
        unsigned cur_file;
@@ -83,7 +85,7 @@ static struct submitter submitters[1];
 static volatile int finish;
 
 static int polled = 1;         /* use IO polling */
-static int fixedbufs = 0;      /* use fixed user buffers */
+static int fixedbufs = 1;      /* use fixed user buffers */
 static int buffered = 0;       /* use buffered IO, not O_DIRECT */
 static int sq_thread_poll = 0; /* use kernel submission/poller thread */
 static int sq_thread_cpu = -1; /* pin above thread to this CPU */
@@ -116,6 +118,11 @@ static int gettid(void)
        return syscall(__NR_gettid);
 }
 
+static unsigned file_depth(struct submitter *s)
+{
+       return (DEPTH + s->nr_files - 1) / s->nr_files;
+}
+
 static void init_io(struct submitter *s, unsigned index)
 {
        struct io_uring_sqe *sqe = &s->sqes[index];
@@ -123,10 +130,17 @@ static void init_io(struct submitter *s, unsigned index)
        struct file *f;
        long r;
 
-       f = &s->files[s->cur_file];
-       s->cur_file++;
-       if (s->cur_file == s->nr_files)
-               s->cur_file = 0;
+       if (s->nr_files == 1) {
+               f = &s->files[0];
+       } else {
+               f = &s->files[s->cur_file];
+               if (f->pending_ios >= file_depth(s)) {
+                       s->cur_file++;
+                       if (s->cur_file == s->nr_files)
+                               s->cur_file = 0;
+               }
+       }
+       f->pending_ios++;
 
        lrand48_r(&s->rand, &r);
        offset = (r % (f->max_blocks - 1)) * BS;
@@ -146,6 +160,7 @@ static void init_io(struct submitter *s, unsigned index)
        sqe->ioprio = 0;
        sqe->fd = f->fd;
        sqe->off = offset;
+       sqe->data = (unsigned long) f;
 }
 
 static int prep_more_ios(struct submitter *s, int max_ios)
@@ -206,10 +221,14 @@ static int reap_events(struct submitter *s)
 
        head = *ring->head;
        do {
+               struct file *f;
+
                barrier();
                if (head == *ring->tail)
                        break;
                cqe = &ring->cqes[head & cq_ring_mask];
+               f = (struct file *) cqe->data;
+               f->pending_ios--;
                if (cqe->res != BS) {
                        printf("io: unexpected ret=%d\n", cqe->res);
                        return -1;
@@ -389,7 +408,7 @@ int main(int argc, char *argv[])
                return 1;
        }
 
-       flags = O_RDONLY;
+       flags = O_RDONLY | O_NOATIME;
        if (!buffered)
                flags |= O_DIRECT;