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From: Richard Palethorpe <rpalethorpe@suse.de>
To: ltp@lists.linux.it
Subject: [LTP] [PATCH v4 0/4] New Fuzzy Sync library API
Date: Mon, 03 Dec 2018 12:40:22 +0100	[thread overview]
Message-ID: <87y396n8ih.fsf@rpws.prws.suse.cz> (raw)
In-Reply-To: <20181120130911.GA9682@rei.lan>

Hello,

Cyril Hrubis <chrubis@suse.cz> writes:

> Hi!
>> Interesting that it is so slow on an x86 system, but it also makes sense
>> with a single core because these are all multi-threaded tests. If the
>> kernel is completely preemptive then it may be theoretically possible to
>> trigger one of these bugs on a single core, but most people seem to
>> think the probability of it happening is lower than on a multi-core
>> machine.
>>
>> I am tempted to simply exit the test with TCONF if it is a single core
>> system. If we do allow them to run on a single core then we have to test
>> that they work reasonably well on single cores (given enough
>> time). Which I just don't think is worth doing based on the times you
>> have given.
>
> Well some of these test still trigger kernel crashes on single CPU
> 300Mhz arm quite reliably. If anything we may want to disable some
> subset on slow single CPUs, but then someone would have to do the
> selection which is probably not worth of the trouble.

OK, I think Jan's patch to limit the sampling time is a reasonably good
solution for now. Also I think based on new evidence we can say the
tests work on single CPUs in practice, it just takes longer.

--
Thank you,
Richard.

  reply	other threads:[~2018-12-03 11:40 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-11-05 15:42 [LTP] [PATCH v4 0/4] New Fuzzy Sync library API Richard Palethorpe
2018-11-05 15:42 ` [LTP] [PATCH v4 1/4] tst_timer: Add nano second conversions Richard Palethorpe
2018-11-05 15:42 ` [LTP] [PATCH v4 2/4] fzsync: Simplify API with start/end race calls and limit exec time Richard Palethorpe
2018-11-22 15:41   ` Cyril Hrubis
2018-11-23 14:55     ` Richard Palethorpe
2018-11-05 15:42 ` [LTP] [PATCH v4 3/4] Convert tests to use fzsync_{start, end}_race API Richard Palethorpe
2018-11-05 15:42 ` [LTP] [PATCH v4 4/4] fzsync: Add delay bias for difficult races Richard Palethorpe
2018-11-29 15:19   ` Cyril Hrubis
2018-11-16 14:33 ` [LTP] [PATCH v4 0/4] New Fuzzy Sync library API Li Wang
2018-11-20 11:35   ` Richard Palethorpe
2018-11-20 13:09     ` Cyril Hrubis
2018-12-03 11:40       ` Richard Palethorpe [this message]
2018-11-22 15:35 ` Cyril Hrubis

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