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        Tue, 27 Sep 2016 10:17:09 -0700 (PDT)
Subject: Re: [PATCH] hppa: Optimize atomic_compare_and_exchange_val_acq
To: Florian Weimer <fw@deneb.enyo.de>,
 John David Anglin <dave.anglin@bell.net>
References: <58B70052-B987-4C41-B603-F3AAB2FDE34B@bell.net>
 <85e42696-2979-c359-ac83-b6cc6a34bb67@redhat.com>
 <CA5F11AD-A3C1-4037-BDC1-31025BDAFEF4@bell.net>
 <87eg4bjdha.fsf@mid.deneb.enyo.de>
Cc: GNU C Library <libc-alpha@sourceware.org>, deller@kernel.org,
 Mike Frysinger <vapier@gentoo.org>, Aurelien Jarno <aurelien@aurel32.net>
From: Carlos O'Donell <carlos@redhat.com>
Message-ID: <a1024fbb-8b25-2e02-e642-0412639e26f7@redhat.com>
Date: Tue, 27 Sep 2016 17:17:00 -0000
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On 09/23/2016 03:13 AM, Florian Weimer wrote:
> * John David Anglin:
> 
>>>> The change was intended as an optimization but tst-stack4 now passes.
>>>
>>> This is a red flag for this patch.
>>
>> The patch has had a significant amount of testing and I'm sure there
>> are no functional issues.  It is important to simplify
>> when possible.
>>
>> Why red flag an improvement in test results?
> 
> I share Carlos' concern.  If this patch appears to fix tst-stack4,
> then it has unforeseen consequences.  We just don't understand the
> full impact of this change.

Exactly.

Before and after the patch the regression testsuite should give
roughly the same results (modulo unreliable tests).
 
I agree that operational hours of testing are important, but it's
not everything one has to consider.

Is the FAIL->PASS for tst-stack4 reliably tied to the addition of
this patch?

-- 
Cheers,
Carlos.