Re: [Qemu-devel] [PATCH] block: init bs->io_base correctly to avoid locking

[Peter Lieven]

Am 10.01.2013 um 13:15 schrieb Paolo Bonzini <address@hidden>:

> Il 10/01/2013 13:12, Peter Lieven ha scritto:
>>>> 
>>>> But perhaps we do not need to start a slice at all when iolimits are
>>>> set.  That is, do
>>>> 
>>>> bs->slice_start = bs->slice_end = bs->slice_time = 0;
>>>> 
>>>> or perhaps even nothing at all since bdrv_io_limits_disable should have
>>>> written those exact values.
>> Or it was set when the BlockDriverState was initialized.
>> 
>> I am not familiar enough with the io limits code to decide if not starting a 
>> slice
>> is also correct.
> 
> I haven't tested it, but if it works, I think it is better.
> 
> Think of it this way: it doesn't matter whether the first I/O operation
> comes immediately after limits are set, or 10 seconds later.  In the
> latter case, bdrv_exceed_io_limits will _already_ start a new slice.  It
> is better to be consistent and always delay the start of the slice.
> 

seems to be working as well.

are you happy with:

block: fix initialization in bdrv_io_limits_enable()

Peter