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Message-Id: <1399598957-7011-1-git-send-email-andres@anarazel.de>
Date:	Fri,  9 May 2014 03:29:15 +0200
From:	Andres Freund <andres@...razel.de>
To:	Borislav Petkov <bp@...e.de>
Cc:	x86@...nel.org, linux-kernel@...r.kernel.org
Subject: 

Hi,

After 3.14 I noticed that perf started to only support software
events.

The reason - found after a some staring deathmatches because the
patches look innocent - is a typo in __flip_bit() introduced by
22085a66c2fab6cf9b9393c056a3600a6b4735de which only takes effect after
c0a639ad0bc6b178b46996bd1f821a04643e2bde. Due to the typo no msr
writes via either msr_clear/set_bit actually write back the new value.
That then causes cpuid limits not to be lifted causing 'my' perf and
very likely some other problems.

There's also a typo in the former commit which makes it impossible to
actually use the MSR_IA32_MISC_ENABLE_LIMIT_CPUID macro correctly.

Regards,

Andres Freund

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