[dm-devel] [PATCH 1/2] dm-ioband: I/O bandwidth controller v1.2.0: Source code and patch

[Xinwei Hu]

Hi Ryo,
2008/7/4 Ryo Tsuruta <ryov at valinux.co.jp>:
> +static void prevent_burst_bios(struct ioband_group *gp, struct bio *bio)
> +{
> +       struct ioband_device *dp = gp->c_banddev;
> +
> +       if (current->flags & PF_KTHREAD) {
> +               /*
> +                * Kernel threads shouldn't be blocked easily since each of
> +                * them may handle BIOs for several groups on several
> +                * partitions.
> +                */
  Might be a stupid question, but doesn't that make more sense to just
check if current->mm == NULL ?
  I think PF_BORROWED_MM is only used when kernel threads doing AIO
for user process, and that should be counted as normal user processes.
Am I miss anything ?