Re: [Qemu-devel] [PATCH 1/5] qemu-img bench

["Denis V. Lunev" <den@openvz.org>]

On 06/03/2016 03:30 PM, Kevin Wolf wrote:
> This adds a qemu-img command that allows doing some simple benchmarks
> for the block layer without involving guest devices and a real VM.
>
> For the start, this implements only a test of sequential reads.
>
> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> ---
>   qemu-img-cmds.hx |   6 ++
>   qemu-img.c       | 190 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
>   qemu-img.texi    |  10 +++
>   3 files changed, 206 insertions(+)
>
> diff --git a/qemu-img-cmds.hx b/qemu-img-cmds.hx
> index e7cded6..f3bd546 100644
> --- a/qemu-img-cmds.hx
> +++ b/qemu-img-cmds.hx
> @@ -9,6 +9,12 @@ STEXI
>   @table @option
>   ETEXI
>   
> +DEF("bench", img_bench,
> +    "bench [-c count] [-d depth] [-f fmt] [-n] [-q] [-s buffer_size] [-t cache] filename")
> +STEXI
> +@item bench [-c @var{count}] [-d @var{depth}] [-f @var{fmt}] [-n] [-q] [-s @var{buffer_size}] [-t @var{cache}] @var{filename}
> +ETEXI
> +
>   DEF("check", img_check,
>       "check [-q] [--object objectdef] [--image-opts] [-f fmt] [--output=ofmt] [-r [leaks | all]] [-T src_cache] filename")
>   STEXI
> diff --git a/qemu-img.c b/qemu-img.c
> index 4b56ad3..d471d10 100644
> --- a/qemu-img.c
> +++ b/qemu-img.c
> @@ -3459,6 +3459,196 @@ out_no_progress:
>       return 0;
>   }
>   
> +typedef struct BenchData {
> +    BlockBackend *blk;
> +    uint64_t image_size;
> +    int bufsize;
> +    int nrreq;
> +    int n;
> +    uint8_t *buf;
> +    QEMUIOVector *qiov;
> +
> +    int in_flight;
> +    uint64_t offset;
> +} BenchData;
> +
> +static void bench_cb(void *opaque, int ret)
> +{
> +    BenchData *b = opaque;
> +    BlockAIOCB *acb;
> +
> +    if (ret < 0) {
> +        error_report("Failed request: %s\n", strerror(-ret));
> +        exit(EXIT_FAILURE);
> +    }
> +    if (b->in_flight > 0) {
> +        b->n--;
> +        b->in_flight--;
> +    }
> +
> +    while (b->n > b->in_flight && b->in_flight < b->nrreq) {
> +        acb = blk_aio_preadv(b->blk, b->offset, b->qiov, 0,
> +                             bench_cb, b);
> +        if (!acb) {
> +            error_report("Failed to issue request");
> +            exit(EXIT_FAILURE);
> +        }
> +        b->in_flight++;
> +        b->offset += b->bufsize;
> +        b->offset %= b->image_size;
> +    }
> +}
> +
> +static int img_bench(int argc, char **argv)
> +{
> +    int c, ret = 0;
> +    const char *fmt = NULL, *filename;
> +    bool quiet = false;
> +    bool image_opts = false;
> +    int count = 75000;
> +    int depth = 64;
> +    size_t bufsize = 4096;
> +    int64_t image_size;
> +    BlockBackend *blk = NULL;
> +    BenchData data = {};
> +    int flags = 0;
> +    bool writethrough;
> +    struct timeval t1, t2;
> +    int i;
> +
> +    for (;;) {
> +        static const struct option long_options[] = {
> +            {"help", no_argument, 0, 'h'},
> +            {"image-opts", no_argument, 0, OPTION_IMAGE_OPTS},
> +            {0, 0, 0, 0}
> +        };
> +        c = getopt_long(argc, argv, "hc:d:f:nqs:t:", long_options, NULL);
> +        if (c == -1) {
> +            break;
> +        }
> +
> +        switch (c) {
> +        case 'h':
> +        case '?':
> +            help();
> +            break;
> +        case 'c':
> +        {
> +            char *end;
> +            errno = 0;
> +            count = strtoul(optarg, &end, 0);
> +            if (errno || *end || count > INT_MAX) {
> +                error_report("Invalid request count specified");
> +                return 1;
> +            }
> +            break;
> +        }
> +        case 'd':
> +        {
> +            char *end;
> +            errno = 0;
> +            depth = strtoul(optarg, &end, 0);
> +            if (errno || *end || depth > INT_MAX) {
> +                error_report("Invalid queue depth specified");
> +                return 1;
> +            }
> +            break;
> +        }
> +        case 'f':
> +            fmt = optarg;
> +            break;
> +        case 'n':
> +            flags |= BDRV_O_NATIVE_AIO;
> +            break;
> +        case 'q':
> +            quiet = true;
> +            break;
> +        case 's':
> +        {
> +            int64_t sval;
> +            char *end;
> +
> +            sval = qemu_strtosz_suffix(optarg, &end, QEMU_STRTOSZ_DEFSUFFIX_B);
> +            if (sval < 0 || sval > INT_MAX || *end) {
> +                error_report("Invalid buffer size specified");
> +                return 1;
> +            }
> +
> +            bufsize = sval;
> +            break;
> +        }
> +        case 't':
> +            ret = bdrv_parse_cache_mode(optarg, &flags, &writethrough);
> +            if (ret < 0) {
> +                error_report("Invalid cache mode");
> +                ret = -1;
> +                goto out;
> +            }
> +            break;
> +        case OPTION_IMAGE_OPTS:
> +            image_opts = true;
> +            break;
> +        }
> +    }
> +
> +    if (optind != argc - 1) {
> +        error_exit("Expecting one image file name");
> +    }
> +    filename = argv[argc - 1];
> +
> +    blk = img_open(image_opts, filename, fmt, flags, writethrough, quiet);
> +    if (!blk) {
> +        ret = -1;
> +        goto out;
> +    }
> +
> +    image_size = blk_getlength(blk);
> +    if (image_size < 0) {
> +        ret = image_size;
> +        goto out;
> +    }
> +
> +    data = (BenchData) {
> +        .blk        = blk,
> +        .image_size = image_size,
> +        .bufsize    = bufsize,
> +        .nrreq      = depth,
> +        .n          = count,
> +    };
> +    printf("Sending %d requests, %d bytes each, %d in parallel\n",
> +        data.n, data.bufsize, data.nrreq);
> +
> +    data.buf = blk_blockalign(blk, data.nrreq * data.bufsize);
> +    data.qiov = g_new(QEMUIOVector, data.nrreq);
> +    for (i = 0; i < data.nrreq; i++) {
> +        qemu_iovec_init(&data.qiov[i], 1);
> +        qemu_iovec_add(&data.qiov[i],
> +                       data.buf + i * data.bufsize, data.bufsize);
> +    }
> +
> +    gettimeofday(&t1, NULL);
> +    bench_cb(&data, 0);
> +
> +    while (data.n > 0) {
> +        main_loop_wait(false);
> +    }
> +    gettimeofday(&t2, NULL);
> +
> +    printf("Run completed in %3.3f seconds.\n",
> +           (t2.tv_sec - t1.tv_sec)
> +           + ((double)(t2.tv_usec - t1.tv_usec) / 1000000));
> +
> +out:
> +    qemu_vfree(data.buf);
> +    blk_unref(blk);
> +
> +    if (ret) {
> +        return 1;
> +    }
> +    return 0;
> +}
> +
> +
>   static const img_cmd_t img_cmds[] = {
>   #define DEF(option, callback, arg_string)        \
>       { option, callback },
> diff --git a/qemu-img.texi b/qemu-img.texi
> index afaebdd..b6b28e3 100644
> --- a/qemu-img.texi
> +++ b/qemu-img.texi
> @@ -131,6 +131,16 @@ Skip the creation of the target volume
>   Command description:
>   
>   @table @option
> +@item bench [-c @var{count}] [-d @var{depth}] [-f @var{fmt}] [-n] [-q] [-s @var{buffer_size}] [-t @var{cache}] @var{filename}
> +
> +Run a simple sequential read benchmark on the specified image. A total number
> +of @var{count} I/O requests is performed, each @var{buffer_size} bytes in size,
> +and with @var{depth} requests in parallel.
> +
> +If @code{-n} is specified, the native AIO backend is used if possible. On
> +Linux, this option only works if @code{-t none} or @code{-t directsync} is
> +specified as well.
> +
>   @item check [-f @var{fmt}] [--output=@var{ofmt}] [-r [leaks | all]] [-T @var{src_cache}] @var{filename}
>   
>   Perform a consistency check on the disk image @var{filename}. The command can
Reviewed-by: Denis V. Lunev <den@openvz.org>