From: Andres Freund <andres@anarazel.de>
To: Borislav Petkov <bp@suse.de>
Cc: x86@kernel.org, linux-kernel@vger.kernel.org
Subject:
Date: Fri, 9 May 2014 03:29:15 +0200 [thread overview]
Message-ID: <1399598957-7011-1-git-send-email-andres@anarazel.de> (raw)
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
next reply other threads:[~2014-05-09 1:29 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-05-09 1:29 Andres Freund [this message]
2014-05-09 1:29 ` [PATCH 1/2] x86: Fix typo preventing msr_set/clear_bit from having an effect Andres Freund
2014-05-09 7:54 ` Borislav Petkov
2014-05-09 10:39 ` Andres Freund
2014-05-09 10:46 ` Borislav Petkov
2014-05-09 16:31 ` [tip:x86/urgent] x86: Fix typo preventing msr_set/ clear_bit " tip-bot for Andres Freund
2014-05-09 1:29 ` [PATCH 2/2] x86: Fix typo in MSR_IA32_MISC_ENABLE_LIMIT_CPUID macro Andres Freund
2014-05-09 7:57 ` Borislav Petkov
2014-05-09 10:33 ` Borislav Petkov
2014-05-09 17:02 ` Joe Perches
2014-05-09 21:31 ` [PATCH] checkpatch: Warn on #defines ending in semicolon Joe Perches
2014-05-09 21:47 ` Thomas Gleixner
2014-05-09 21:59 ` Joe Perches
2014-05-09 16:31 ` [tip:x86/urgent] x86: Fix typo in MSR_IA32_MISC_ENABLE_LIMIT_CPUID macro tip-bot for Andres Freund
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