From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from eggs.gnu.org ([2001:4830:134:3::10]:56744)
	by lists.gnu.org with esmtp (Exim 4.71)
	(envelope-from <armbru@redhat.com>) id 1ZUIzI-0002Wb-Sx
	for qemu-devel@nongnu.org; Tue, 25 Aug 2015 14:30:25 -0400
Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71)
	(envelope-from <armbru@redhat.com>) id 1ZUIzE-0004Fj-UB
	for qemu-devel@nongnu.org; Tue, 25 Aug 2015 14:30:24 -0400
Received: from mx1.redhat.com ([209.132.183.28]:42268)
	by eggs.gnu.org with esmtp (Exim 4.71)
	(envelope-from <armbru@redhat.com>) id 1ZUIzE-0004EX-OC
	for qemu-devel@nongnu.org; Tue, 25 Aug 2015 14:30:20 -0400
From: Markus Armbruster <armbru@redhat.com>
References: <29C62C49-06A5-4F99-8062-7269A28C29A3@gmail.com>
	<55DB98E1.600@redhat.com> <87twrnmtet.fsf@blackfin.pond.sub.org>
	<317E9D35-17C6-4218-B58C-CEE71F8A400F@gmail.com>
	<CAFEAcA_efBzdG1azrSQ3+RxTpdLSzDqaR_3wQ+-ftXCidW=8HA@mail.gmail.com>
	<AF872D1D-1E56-4518-BF91-70412B142216@gmail.com>
Date: Tue, 25 Aug 2015 20:30:17 +0200
In-Reply-To: <AF872D1D-1E56-4518-BF91-70412B142216@gmail.com>
	(Programmingkid's message of "Tue, 25 Aug 2015 11:50:18 -0400")
Message-ID: <87wpwjgr0m.fsf@blackfin.pond.sub.org>
MIME-Version: 1.0
Content-Type: text/plain
Subject: Re: [Qemu-devel] [PATCH] qdev-monitor.c: Add device id generation
List-Id: <qemu-devel.nongnu.org>
List-Unsubscribe: <https://lists.nongnu.org/mailman/options/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=unsubscribe>
List-Archive: <http://lists.nongnu.org/archive/html/qemu-devel>
List-Post: <mailto:qemu-devel@nongnu.org>
List-Help: <mailto:qemu-devel-request@nongnu.org?subject=help>
List-Subscribe: <https://lists.nongnu.org/mailman/listinfo/qemu-devel>,
	<mailto:qemu-devel-request@nongnu.org?subject=subscribe>
To: Programmingkid <programmingkidx@gmail.com>
Cc: Peter Maydell <peter.maydell@linaro.org>, qemu-devel qemu-devel <qemu-devel@nongnu.org>

Programmingkid <programmingkidx@gmail.com> writes:

> On Aug 25, 2015, at 11:33 AM, Peter Maydell wrote:
>
>> On 25 August 2015 at 16:25, Programmingkid <programmingkidx@gmail.com> wrote:
>>> On Aug 25, 2015, at 8:42 AM, Markus Armbruster wrote:
>>>> Eric Blake <eblake@redhat.com> writes:
>>>> 
>>>>> On 08/24/2015 12:53 PM, Programmingkid wrote:
>>>>>> +/* USB's max number of devices is 127. This number is 3 digits long. */
>>>>>> +#define MAX_NUM_DIGITS_FOR_USB_ID 3
>>>> 
>>>> This limit makes no sense to me.
>>> 
>>> The limit is used to decide how many characters the device_id
>>> string is going to have.
>>> Three digits would be 0 to 999 device ID's would be supported. I
>>> can't imagine
>>> anyone spending the time to add that many devices.
>> 
>> Arbitrary limits are often a bad idea, especially when
>> they're easy to avoid, as here.
>
> Knowing QEMU's limits can save the user from crashes and other
> problems. There is
> only a finite amount of memory available to QEMU. 

Repeat N times:
    device_add FOO,id=hot
    device_del hot

Memory usage independent of N (unless we leak, but that would be a bug).

[...]