From: Suresh Siddha <suresh.b.siddha@intel.com>
To: Avi Kivity <avi@redhat.com>
Cc: "Cui, Dexuan" <dexuan.cui@intel.com>,
Sheng Yang <sheng@linux.intel.com>, Ingo Molnar <mingo@elte.hu>,
"H. Peter Anvin" <hpa@zytor.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"kvm@vger.kernel.org" <kvm@vger.kernel.org>
Subject: Re: [PATCH 1/2] x86: eliminate TS_XSAVE
Date: Tue, 04 May 2010 11:03:29 -0700 [thread overview]
Message-ID: <1272996209.2833.1.camel@sbs-t61.sc.intel.com> (raw)
In-Reply-To: <1272812038-32484-2-git-send-email-avi@redhat.com>
On Sun, 2010-05-02 at 07:53 -0700, Avi Kivity wrote:
> The fpu code currently uses current->thread_info->status & TS_XSAVE as
> a way to distinguish between XSAVE capable processors and older processors.
> The decision is not really task specific; instead we use the task status to
> avoid a global memory reference - the value should be the same across all
> threads.
>
> Eliminate this tie-in into the task structure by using an alternative
> instruction keyed off the XSAVE cpu feature; this results in shorter and
> faster code, without introducing a global memory reference.
>
> Signed-off-by: Avi Kivity <avi@redhat.com>
Acked-by: Suresh Siddha <suresh.b.siddha@intel.com>
next prev parent reply other threads:[~2010-05-04 18:04 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-05-02 14:53 [PATCH 0/2] x86 FPU API Avi Kivity
2010-05-02 14:53 ` [PATCH 1/2] x86: eliminate TS_XSAVE Avi Kivity
2010-05-02 17:38 ` Brian Gerst
2010-05-02 17:44 ` Avi Kivity
2010-05-03 21:45 ` H. Peter Anvin
2010-05-04 7:41 ` Avi Kivity
2010-05-04 18:15 ` Suresh Siddha
2010-05-04 18:24 ` H. Peter Anvin
2010-05-05 7:30 ` Avi Kivity
2010-05-05 12:10 ` H. Peter Anvin
2010-05-05 12:12 ` H. Peter Anvin
2010-05-04 18:03 ` Suresh Siddha [this message]
2010-05-02 14:53 ` [PATCH 2/2] x86: Introduce 'struct fpu' and related API Avi Kivity
2010-05-04 18:12 ` Suresh Siddha
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