t/io_uring: allow flexible IO threads assignment

This patch allows to flexibly assign IO threads to fileset. When
you specify:

t/io_uring -n 5 /dev/dev1 dev/dev2

First file/device will get 3 IO threads and second file/device
remaining 2 IO threads. When there is more files then IO threads,
IO thread may get assigned multiple files/devices.

Signed-off-by: Andrzej Jakowski <andrzej.jakowski@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/t/io_uring.c b/t/io_uring.c
index 77d27859710301a5a9eb09bbc273ba27b6b73c31..23c9d60677a0c44782cd77a4a581669beed3dd2e 100644 (file)
--- a/t/io_uring.c
+++ b/t/io_uring.c
@@ -543,7 +543,7 @@ static void file_depths(char *buf)
        }
 }
 
-static void usage(char *argv)
+static void usage(char *argv, int status)
 {
        printf("%s [options] -- [filenames]\n"
                " -d <int>  : IO Depth, default %d\n"
@@ -556,14 +556,15 @@ static void usage(char *argv)
                " -n <int>  : Number of threads, default %d\n",
                argv, DEPTH, BATCH_SUBMIT, BATCH_COMPLETE, BS, polled,
                fixedbufs, register_files, nthreads);
-       exit(0);
+       exit(status);
 }
 
 int main(int argc, char *argv[])
 {
        struct submitter *s;
        unsigned long done, calls, reap;
-       int err, i, j, flags, fd, opt;
+       int err, i, j, flags, fd, opt, threads_per_f, threads_rem = 0, nfiles;
+       struct file f;
        char *fdepths;
        void *ret;
 
@@ -601,7 +602,7 @@ int main(int argc, char *argv[])
                case 'h':
                case '?':
                default:
-                       usage(argv[0]);
+                       usage(argv[0], 0);
                        break;
                }
        }
@@ -620,37 +621,57 @@ int main(int argc, char *argv[])
 
        j = 0;
        i = optind;
+       nfiles = argc - i;
+       if (!nfiles) {
+               printf("no files specified\n");
+               usage(argv[0], 1);
+       }
+       threads_per_f = nthreads / nfiles;
+       /* make sure each thread gets assigned files */
+       if (threads_per_f == 0) {
+               threads_per_f = 1;
+       } else {
+               threads_rem = nthreads - threads_per_f * nfiles;
+       }
        while (!do_nop && i < argc) {
-               struct file *f;
+               int k, limit;
+
+               memset(&f, 0, sizeof(f));
 
-               s = get_submitter(j);
-               if (s->nr_files == MAX_FDS) {
-                       printf("Max number of files (%d) reached\n", MAX_FDS);
-                       break;
-               }
                fd = open(argv[i], flags);
                if (fd < 0) {
                        perror("open");
                        return 1;
                }
-
-               f = &s->files[s->nr_files];
-               f->real_fd = fd;
-               if (get_file_size(f)) {
+               f.real_fd = fd;
+               if (get_file_size(&f)) {
                        printf("failed getting size of device/file\n");
                        return 1;
                }
-               if (f->max_blocks <= 1) {
+               if (f.max_blocks <= 1) {
                        printf("Zero file/device size?\n");
                        return 1;
                }
-               f->max_blocks--;
+               f.max_blocks--;
+
+               limit = threads_per_f;
+               limit += threads_rem > 0 ? 1 : 0;
+               for (k = 0; k < limit; k++) {
+                       s = get_submitter((j + k) % nthreads);
 
-               printf("Added file %s (submitter %d)\n", argv[i], s->index);
-               s->nr_files++;
+                       if (s->nr_files == MAX_FDS) {
+                               printf("Max number of files (%d) reached\n", MAX_FDS);
+                               break;
+                       }
+
+                       memcpy(&s->files[s->nr_files], &f, sizeof(f));
+
+                       printf("Added file %s (submitter %d)\n", argv[i], s->index);
+                       s->nr_files++;
+               }
+               threads_rem--;
                i++;
-               if (++j >= nthreads)
-                       j = 0;
+               j += limit;
        }
 
        arm_sig_int();