From: Rik van Riel <riel@redhat.com>
To: Borislav Petkov <bp@alien8.de>
Cc: Andy Lutomirski <luto@amacapital.net>,
"Maciej W. Rozycki" <macro@linux-mips.org>,
Ingo Molnar <mingo@kernel.org>, Oleg Nesterov <oleg@redhat.com>,
X86 ML <x86@kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Linus Torvalds <torvalds@linux-foundation.org>
Subject: Re: [RFC PATCH] x86, fpu: Use eagerfpu by default on all CPUs
Date: Mon, 23 Feb 2015 10:51:26 -0500 [thread overview]
Message-ID: <54EB4C7E.7010706@redhat.com> (raw)
In-Reply-To: <20150223150350.GB22753@pd.tnic>
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On 02/23/2015 10:03 AM, Borislav Petkov wrote:
> On Mon, Feb 23, 2015 at 07:51:04AM -0500, Rik van Riel wrote:
>> At that point we either load the FPU context, or we set CR0.TS.
>
> Right, but provided eager doesn't bring any slowdown, we can drop
> the TS fiddling altogether and only load FPU context.
Agreed.
However, we would still need the rest of the kernel code to
check whether userspace FPU context is loaded in the registers
or not. We cannot simplify to the point of assuming that the
FPU state will always be loaded when in eager mode.
- --
All rights reversed
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next prev parent reply other threads:[~2015-02-23 15:52 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-02-20 18:58 [RFC PATCH] x86, fpu: Use eagerfpu by default on all CPUs Andy Lutomirski
2015-02-20 19:05 ` Borislav Petkov
2015-02-21 9:31 ` Ingo Molnar
2015-02-21 16:38 ` Borislav Petkov
2015-02-21 17:29 ` Borislav Petkov
2015-02-21 18:39 ` Ingo Molnar
2015-02-21 19:15 ` Borislav Petkov
2015-02-21 19:23 ` Ingo Molnar
2015-02-21 21:36 ` Borislav Petkov
2015-02-22 8:18 ` Ingo Molnar
2015-02-22 8:22 ` Ingo Molnar
2015-02-22 10:48 ` Borislav Petkov
2015-02-22 12:50 ` Borislav Petkov
2015-02-22 12:57 ` Ingo Molnar
2015-02-22 13:21 ` Borislav Petkov
2015-02-22 0:34 ` Maciej W. Rozycki
2015-02-22 2:18 ` Andy Lutomirski
2015-02-22 11:06 ` Borislav Petkov
2015-02-23 1:45 ` Rik van Riel
2015-02-23 5:22 ` Andy Lutomirski
2015-02-23 12:51 ` Rik van Riel
2015-02-23 15:03 ` Borislav Petkov
2015-02-23 15:51 ` Rik van Riel [this message]
2015-02-23 18:06 ` Borislav Petkov
2015-02-23 21:17 ` Maciej W. Rozycki
2015-02-23 21:21 ` Rik van Riel
2015-02-23 22:14 ` Linus Torvalds
2015-02-24 0:56 ` Maciej W. Rozycki
2015-02-24 0:59 ` Andy Lutomirski
2015-02-23 22:27 ` Maciej W. Rozycki
2015-02-23 23:44 ` Andy Lutomirski
2015-02-24 2:14 ` Maciej W. Rozycki
2015-02-24 2:31 ` Andy Lutomirski
2015-02-24 14:43 ` Rik van Riel
2015-02-21 18:34 ` Ingo Molnar
2015-02-23 14:59 ` Oleg Nesterov
2015-02-23 15:11 ` Borislav Petkov
2015-02-23 15:53 ` Rik van Riel
2015-02-23 18:40 ` Oleg Nesterov
2015-02-24 19:15 ` Denys Vlasenko
2015-02-25 0:07 ` Andy Lutomirski
2015-02-25 10:37 ` Borislav Petkov
2015-02-25 10:50 ` Ingo Molnar
2015-02-25 10:45 ` Ingo Molnar
2015-02-25 17:12 ` Some results (was: Re: [RFC PATCH] x86, fpu: Use eagerfpu by default on all CPUs) Borislav Petkov
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