linux-kernel - Re: [PATCH] x86/FPU: Fix FPU handling on legacy FPU machines

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Date:	Sat, 12 Mar 2016 13:27:04 +0100
From:	Borislav Petkov <bp@...en8.de>
To:	Bryan O'Donoghue <pure.logic@...us-software.ie>
Cc:	Linus Torvalds <torvalds@...ux-foundation.org>,
	Ingo Molnar <mingo@...nel.org>,
	Andy Lutomirski <luto@...capital.net>,
	Andy Shevchenko <andy.shevchenko@...il.com>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"x86@...nel.org" <x86@...nel.org>,
	Fenghua Yu <fenghua.yu@...el.com>,
	"H. Peter Anvin" <hpa@...or.com>,
	Thomas Gleixner <tglx@...utronix.de>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Dave Hansen <dave.hansen@...ux.intel.com>,
	Oleg Nesterov <oleg@...hat.com>,
	"Yu, Yu-cheng" <yu-cheng.yu@...el.com>
Subject: Re: [PATCH] x86/FPU: Fix FPU handling on legacy FPU machines

On Sat, Mar 12, 2016 at 12:04:49PM +0000, Bryan O'Donoghue wrote:
> Busy with the dayjob :) so I haven't updated on Galileo since 
> 
> 4b696dcb1a55e40648ad0eec4af991c72f945a85 (Feb 28 or so)

That's 4.5-rc5-ish and the FPU rewrite came during 4.2. BUT!,

  58122bf1d856 x86/fpu: Default eagerfpu=on on all CPUs

which is in tip currently, made eagerfpu default and we know that
eagerfpu=off makes the issue go away.

So the bug was there, just it wasn't being hit on Quark. Until
58122bf1d856...

-- 
Regards/Gruss,
    Boris.

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