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From: cross@spitfire.i.gajendra.net (Dan Cross)
Newsgroups: comp.arch
Subject: Re: MSI interrupts
Date: Tue, 25 Mar 2025 11:14:35 -0000 (UTC)
Organization: PANIX Public Access Internet and UNIX, NYC
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References: <vqto79$335c6$1@dont-email.me> <vrsaro$1faj3$9@dont-email.me> <vrsefn$siu$2@reader1.panix.com> <vrt2sb$27c13$2@dont-email.me>
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In article <vrt2sb$27c13$2@dont-email.me>,
Chris M. Thomasson <chris.m.thomasson.1@gmail.com> wrote:
>On 3/24/2025 1:14 PM, Dan Cross wrote:
>> In article <vrsaro$1faj3$9@dont-email.me>,
>> Chris M. Thomasson <chris.m.thomasson.1@gmail.com> wrote:
>>> On 3/24/2025 11:49 AM, Dan Cross wrote:
>>>> [snip]
>>>> I'm sure one could do a lockless pop using a cmp exchange, but I
>>>> wanted to a scenario where one would want to hold onto both
>>>> locks throughout the critical section for some reason.
>>>> I just don't see how this works in the proposed scenario.
>>>
>>> You want to hold lock A while lock B us being used? That can be tricky.
>> 
>> Really?  This happens all the time.  Of course it can be tricky,
>> as concurrent programming always is, but it's incredibly normal.
>
>Locking order comes into play here. Uggg... I have seen nightmare code 
>that was using recursion as well... It deadlocked at a certain depth, 
>only under the right conditions. The locking order was not properly 
>respected...

Well, of course it does.  But it's still something that people
do all the time.

	- Dan C.