Re: [Qemu-devel] [RFC]QEMU disk I/O limits

[Zhi Yong Wu <zwu.kernel@gmail.com>]

On Thu, Jun 2, 2011 at 5:33 PM, Michal Suchanek <hramrach@centrum.cz> wrote:
> On 1 June 2011 05:12, Zhi Yong Wu <wuzhy@linux.vnet.ibm.com> wrote:
>> On Tue, May 31, 2011 at 03:55:49PM -0400, Vivek Goyal wrote:
>>>Date: Tue, 31 May 2011 15:55:49 -0400
>>>From: Vivek Goyal <vgoyal@redhat.com>
>>>To: Zhi Yong Wu <wuzhy@linux.vnet.ibm.com>
>>>Cc: kwolf@redhat.com, aliguori@us.ibm.com, stefanha@linux.vnet.ibm.com,
>>>       kvm@vger.kernel.org, guijianfeng@cn.fujitsu.com,
>>>       qemu-devel@nongnu.org, wuzhy@cn.ibm.com,
>>>       herbert@gondor.hengli.com.au, luowenj@cn.ibm.com, zhanx@cn.ibm.com,
>>>       zhaoyang@cn.ibm.com, llim@redhat.com, raharper@us.ibm.com
>>>Subject: Re: [Qemu-devel] [RFC]QEMU disk I/O limits
>>>User-Agent: Mutt/1.5.21 (2010-09-15)
>>>
>>>On Mon, May 30, 2011 at 01:09:23PM +0800, Zhi Yong Wu wrote:
>>>
>>>[..]
>>>>     3.) How the users enable and play with it
>>>>     QEMU -drive option will be extended so that disk I/O limits can be specified on its command line, such as -drive [iops=xxx,][throughput=xxx] or -drive [iops_rd=xxx,][iops_wr=xxx,][throughput=xxx] etc. When this argument is specified, it means that "disk I/O limits" feature is enabled for this drive disk.
>>>
>>>How does throughput interface look like? is it bytes per second or something
>>>else?
>> HI, Vivek,
>> It will be a value based on bytes per second.
>>
>>>
>>>Do we have read and write variants for throughput as we have for iops.
>> QEMU code has two variants "rd_bytes, wr_bytes", but we maybe need to get their bytes per second.
>>
>>>
>>>if you have bytes interface(as kenrel does), then "bps_rd" and "bps_wr"
>>>might be good names too for thoughput interface.
>> I agree with you, and can change them as your suggestions.
>>
>
> Changing them this way is not going to be an improvement. While
> rd_bytes and wr_bytes lack the time interval specification bps_rd and
right, rd_bytes and wr_bytes lack.
> bps_wr is ambiguous. Is that bits? bytes? Sure, there should be some
if we implement them, they will be bytes.
> distinction by capitalization but that does not apply since qemu
> arguments are all lowercase.
Michal,
maybe you misunderstand what i mean. I mean that two variables
rd_bytes and wr_bytes exist in block.c file, and are not qemu
arguments. But bps_rd and bps_wr wil be added as qemu arguments.

Regards,

Zhiyong Wu
>
> Thanks
>
> Michal
> --
> To unsubscribe from this list: send the line "unsubscribe kvm" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>



-- 
Regards,

Zhi Yong Wu