[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Qemu-devel] [PATCH 13/16] block: Implement bdrv_append() without bd

From: Alberto Garcia
Subject: Re: [Qemu-devel] [PATCH 13/16] block: Implement bdrv_append() without bdrv_swap()
Date: Fri, 18 Sep 2015 13:45:56 +0200
User-agent: Notmuch/0.13.2 (http://notmuchmail.org) Emacs/23.2.1 (i486-pc-linux-gnu)

On Thu 17 Sep 2015 03:48:17 PM CEST, Kevin Wolf wrote:

> +static void swap_feature_fields(BlockDriverState *bs_top,
> +                                BlockDriverState *bs_new)
> +{
> +    BlockDriverState tmp;
> +
> +    bdrv_move_feature_fields(&tmp, bs_top);
> +    bdrv_move_feature_fields(bs_top, bs_new);
> +    bdrv_move_feature_fields(bs_new, &tmp);
> +
> +    assert(!bs_new->io_limits_enabled);
> +    if (bs_top->io_limits_enabled) {
> +        bdrv_io_limits_enable(bs_new, throttle_group_get_name(bs_top));
> +        bdrv_io_limits_disable(bs_top);
> +    }
> +}

I would use 'if (bs_top->throttle_state != NULL)' instead. That pointer
is set if and only if the BDS has I/O limits set.

bs->io_limits_enabled can be set to false in order to bypass the limits
temporarily without removing the BDS's throttling settings (e.g in

I actually think that we can get rid of io_limits_enabled in several
places (if not completely), but I will take care of that in a separate

The only scenario that could cause problems is if bs->throttle_state is
set but bs->io_limits_enabled is false when swap_feature_fields() is
called, but I don't think that's possible in this case.


reply via email to

[Prev in Thread] Current Thread [Next in Thread]