Re: WinXPSP2, Intel Core2Duo, Kernel drivers

Hi Calvin

It has little to do with whether it's supported or unsupported. Human beings
are extremely creative when it comes to making bugs. I figure it's because
we are not being fully debugged.

Well, you can think of my examples as of ones of the bugs if you wish -
no matter how you call them, these are the examples of doing something
you are not supposed to do, which may have undesirable effects (unless
you are 100% sure you know what you are doing)


Testing driver on UP thoroughly is a must IMO.

Certainly, the more thorougly your driver is tested, the better it is
for you. However, it does not mean that your driver has to be "non-SMP
aware" one. In actuality, the very fact that driver is "non-SMP aware"
one somehow implies that it does something it is not supposed to...


Anton Bassov

Calvin Guan wrote:
It has little to do with whether it's supported or unsupported. Human beings
are extremely creative when it comes to making bugs. I figure it's because
we are not being fully debugged.

Testing driver on UP thoroughly is a must IMO.

--
Calvin Guan (DDK MVP)
Sr. Staff Engineer
NetXtreme Vista/Longhorn Server Miniport
Broadcom Corporation
Connecting Everything(r)

<soviet_bloke@xxxxxxxxxxx> wrote in message
news:1157605339.245398.35080@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Hi Calvin

once the driver works fine on SMP machine, it
automatically implies it will work fine on UP one as well.

Believe it or not, this is not true.

My statement is based upon the "bold" assumption that the driver in
question relies only upon the "supported" stuff. Certainly, if it, say,
uses SYNCH_LEVEL directly (i.e. does something that drivers are not
supposed to do), then it may work fine on MP kernel and fail on UP one
- on UP kernel SYNCH_LEVEL equals DISPATCH_LEVEL, although on MP one it
equals CLOCK2_LEVEL. Similarly, if it uses KeQueryPerformanceCounter()
in order to measure the elapsed time(again, something drivers are not
supposed to do), implications may be quite different for UP and MP
kernels. However, as long as it plays by the rules, my statement
holds....



Anton Bassov

Calvin Guan wrote:
<soviet_bloke@xxxxxxxxxxx> wrote in message
news:1157600038.483526.248840@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
In fact, it just does not make sense to write "non-SMP aware" drivers,
in the first place

well said.

once the driver works fine on SMP machine, it
automatically implies it will work fine on UP one as well.

Believe it or not, this is not true.

--
Calvin Guan (DDK MVP)
Sr. Staff Engineer
NetXtreme Vista/Longhorn Server Miniport
Broadcom Corporation
Connecting Everything(r)


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