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Subject: Re: PREEMPT_RT_FULL on x86-32 machine
To:     Pavel Machek <pavel@ucw.cz>
Cc:     linux-rt-users@vger.kernel.org,
        kernel list <linux-kernel@vger.kernel.org>, mwhitehe@redhat.com
References: <20190622081954.GA10751@amd>
 <2804bc5b-18c1-2793-171c-045c0725a6a7@siemens.com>
 <20190624105340.GA21414@amd>
From:   Jan Kiszka <jan.kiszka@siemens.com>
Message-ID: <903a1932-c530-5c45-31ab-a3b4d61d48eb@siemens.com>
Date:   Mon, 24 Jun 2019 12:58:04 +0200
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On 24.06.19 12:53, Pavel Machek wrote:
> Hi!
> 
>>> Is full preemption supposed to work on x86-32 machines?
>>>
>>> Because it does not work for me. It crashes early in boot, no messages
>>> make it to console. Similar configuration for x86-64 boots ok.
>>>
>>
>> Maybe you can also tell which version(s) you tried, and in which
>> configuration(s), and how the crash looked like.
> 
> I wanted to know if the configuration is supposed to work at all
> before starting heavy debugging. From your reply I assume that it
> should work.

We still have at least one 4.4-based 32-bit-only target on RT. But there is 
likely more, even though I'm promoting to use at least a 64-bit kernel on 64-bit 
capable hw for many years, irrespective of RT.

Jan

> 
> I tried 4.19.13-rt1-cip1 among others. Crash is early in boot, I can
> try some early printing...
> 
> Best regards,
> 									Pavel
> 

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