Subject: IPL_LOCK oddity
To: None <tech-kern@netbsd.org>
From: Bill Studenmund <wrstuden@netbsd.org>
List: tech-kern
Date: 08/23/2006 17:08:55
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In chatting with dbj, I was reminded that on a number of ports, we have=20
IPL_SERIAL higher than IPL_LOCK. IPL_IPI also is higher than IPL_LOCK on=20
x86 (I didn't check extensively).

The problem is that our serial port code, in an effort to be MP-safe,=20
takes locks. Including the code that runs at IPL_SERIAL. Thus IPL_SERIAL >=
=20
IPL_LOCK is very very bad. :-)

So is there any reason we don't just change IPL_LOCK to IPL_SERIAL?

Also, is the IPI code structured so that it doesn't have to take locks?

Take care,

Bill

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