Re: [Qemu-devel] [PATCH] virtio-blk: add virtio_blk_handle_read trace event

[Paolo Bonzini <pbonzini@redhat.com>]

On 12/22/2011 02:17 PM, Stefan Hajnoczi wrote:
> There already exists a virtio_blk_handle_write trace event as well as
> completion events.  Add the virtio_blk_handle_read event so it's easy to
> trace virtio-blk requests for both read and write operations.
>
> Signed-off-by: Stefan Hajnoczi<stefanha@linux.vnet.ibm.com>
> ---
>   hw/virtio-blk.c |    2 ++
>   trace-events    |    1 +
>   2 files changed, 3 insertions(+), 0 deletions(-)
>
> diff --git a/hw/virtio-blk.c b/hw/virtio-blk.c
> index ef27421..cf275e4 100644
> --- a/hw/virtio-blk.c
> +++ b/hw/virtio-blk.c
> @@ -340,6 +340,8 @@ static void virtio_blk_handle_read(VirtIOBlockReq *req)
>
>       bdrv_acct_start(req->dev->bs,&req->acct, req->qiov.size, BDRV_ACCT_READ);
>
> +    trace_virtio_blk_handle_read(req, sector, req->qiov.size / 512);
> +
>       if (sector&  req->dev->sector_mask) {
>           virtio_blk_rw_complete(req, -EIO);
>           return;
> diff --git a/trace-events b/trace-events
> index 514849a..2875ea8f6 100644
> --- a/trace-events
> +++ b/trace-events
> @@ -73,6 +73,7 @@ bdrv_co_copy_on_readv(void *bs, int64_t sector_num, int nb_sectors, int64_t clus
>   virtio_blk_req_complete(void *req, int status) "req %p status %d"
>   virtio_blk_rw_complete(void *req, int ret) "req %p ret %d"
>   virtio_blk_handle_write(void *req, uint64_t sector, size_t nsectors) "req %p sector %"PRIu64" nsectors %zu"
> +virtio_blk_handle_read(void *req, uint64_t sector, size_t nsectors) "req %p sector %"PRIu64" nsectors %zu"
>
>   # posix-aio-compat.c
>   paio_submit(void *acb, void *opaque, int64_t sector_num, int nb_sectors, int type) "acb %p opaque %p sector_num %"PRId64" nb_sectors %d type %d"

Acked-by: Paolo Bonzini <pbonzini@redhat.com>