Attachment 1629144 Details for Bug 1765547 – Test program to demonstrate the issue

Test program to demonstrate the issue

parallel-falloc-and-pwrite.c (text/plain), 1.69 KB, created by Hanna Czenczek on 2019-10-25 11:47:27 UTC

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Creator: Hanna Czenczek

Created: 2019-10-25 11:47:27 UTC

Size: 1.69 KB

patch

obsolete

>#define _GNU_SOURCE
>
>#include <assert.h>
>#include <fcntl.h>
>#include <libaio.h>
>#include <pthread.h>
>#include <stdio.h>
>#include <stdlib.h>
>#include <string.h>
>#include <unistd.h>
>
>// Define this to perform the fallocate and the pwrite sequentially
>// instead of in parallel
>
>// #define IN_ORDER
>
>
>int fd;
>
>void *falloc_thread(void *arg)
>{
>    int ret;
>
>    (void)arg;
>
>    puts("starting fallocate");
>
>    ret = fallocate(fd, 0, 0, 4096);
>    assert(ret == 0);
>
>    puts("fallocate done");
>
>    return NULL;
>}
>
>int main(int argc, char *argv[])
>{
>    pthread_t falloc_thr;
>    int ret;
>
>    if (argc != 2) {
>        fprintf(stderr, "Usage: %s <scratch file>\n", argv[0]);
>        return 1;
>    }
>
>    fd = open(argv[1], O_CREAT | O_RDWR | O_TRUNC | O_DIRECT, 0666);
>    assert(fd >= 0);
>
>    void *buf = aligned_alloc(4096, 4096);
>    memset(buf, 42, 4096);
>
>    io_context_t ctx = 0;
>    ret = io_setup(1, &ctx);
>    assert(ret == 0);
>
>    ret = pthread_create(&falloc_thr, NULL, &falloc_thread, NULL);
>    assert(ret == 0);
>
>#ifdef IN_ORDER
>    ret = pthread_join(falloc_thr, NULL);
>    assert(ret == 0);
>#endif
>
>    struct iocb ior;
>    io_prep_pwrite(&ior, fd, buf, 4096, 4096);
>
>    puts("submitting pwrite");
>
>    struct iocb *ios[] = { &ior };
>    ret = io_submit(ctx, 1, ios);
>    assert(ret == 1);
>
>    struct io_event evs[1];
>    ret = io_getevents(ctx, 1, 1, evs, NULL);
>    assert(ret == 1);
>
>    puts("pwrite done");
>
>#ifndef IN_ORDER
>    ret = pthread_join(falloc_thr, NULL);
>    assert(ret == 0);
>#endif
>
>    ret = io_destroy(ctx);
>    assert(ret == 0);
>
>    close(fd);
>    free(buf);
>
>    puts("\nHexdump should show 4k of 0s and 4k of 42s:\n");
>
>    execlp("hexdump", "hexdump", "-C", argv[1], NULL);
>    return 1;
>}

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Attachments on bug 1765547: 1629144 | 1630037