From: "H. Peter Anvin" <hpa@zytor.com>
To: Avi Kivity <avi@redhat.com>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>,
mingo@kernel.org, torvalds@linux-foundation.org,
andreas.herrmann3@amd.com, bp@amd64.org, robert.richter@amd.com,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 3/6] x86, kvm: use kernel_fpu_begin/end() in kvm_load/put_guest_fpu()
Date: Wed, 19 Sep 2012 10:26:06 -0700 [thread overview]
Message-ID: <505A002E.6050304@zytor.com> (raw)
In-Reply-To: <5059FF67.6050005@redhat.com>
On 09/19/2012 10:22 AM, Avi Kivity wrote:
>
> Note, we could also go in a different direction and make
> kernel_fpu_begin() use preempt notifiers and thus make its users
> preemptible. But that's for a separate patchset.
>
Where would you put the state if you were preempted? You want to
allocate a full extra buffer for the kernel xstate for each thread just
in case? ("Yes" is a valid answer to that question, but it is a fair
chunk of memory.)
-hpa
next prev parent reply other threads:[~2012-09-19 17:26 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-08-24 21:12 [PATCH 0/6] x86, fpu: cleanups, introduce non-lazy FPU restore for xsave Suresh Siddha
2012-08-24 21:12 ` [PATCH 1/6] x86, fpu: drop_fpu() before restoring new state from sigframe Suresh Siddha
2012-08-24 22:13 ` [tip:x86/fpu] " tip-bot for Suresh Siddha
2012-09-19 0:01 ` tip-bot for Suresh Siddha
2012-08-24 21:12 ` [PATCH 2/6] x86, fpu: remove unnecessary user_fpu_end() in save_xstate_sig() Suresh Siddha
2012-08-24 22:14 ` [tip:x86/fpu] " tip-bot for Suresh Siddha
2012-08-26 11:30 ` [PATCH 2/6] " Borislav Petkov
2012-09-19 0:02 ` [tip:x86/fpu] " tip-bot for Suresh Siddha
2012-08-24 21:12 ` [PATCH 3/6] x86, kvm: use kernel_fpu_begin/end() in kvm_load/put_guest_fpu() Suresh Siddha
2012-08-24 22:15 ` [tip:x86/fpu] x86, kvm: use kernel_fpu_begin/end() in kvm_load/ put_guest_fpu() tip-bot for Suresh Siddha
2012-09-19 0:03 ` tip-bot for Suresh Siddha
2012-09-19 10:13 ` [PATCH 3/6] x86, kvm: use kernel_fpu_begin/end() in kvm_load/put_guest_fpu() Avi Kivity
2012-09-19 17:18 ` Suresh Siddha
2012-09-19 17:22 ` Avi Kivity
2012-09-19 17:25 ` Suresh Siddha
2012-09-20 9:31 ` Avi Kivity
2012-09-19 17:26 ` H. Peter Anvin [this message]
2012-09-20 9:36 ` Avi Kivity
2012-09-20 0:10 ` Suresh Siddha
2012-09-20 9:50 ` Avi Kivity
2012-09-20 18:01 ` Suresh Siddha
2012-09-22 0:19 ` [tip:x86/fpu] x86, kvm: fix kvm's usage of kernel_fpu_begin/end() tip-bot for Suresh Siddha
2012-08-24 21:13 ` [PATCH 4/6] x86, fpu: always use kernel_fpu_begin/end() for in-kernel FPU usage Suresh Siddha
2012-08-24 22:16 ` [tip:x86/fpu] " tip-bot for Suresh Siddha
2012-09-19 0:04 ` tip-bot for Suresh Siddha
2012-08-24 21:13 ` [PATCH 5/6] lguest, x86: handle guest TS bit for lazy/non-lazy fpu host models Suresh Siddha
2012-08-24 22:16 ` [tip:x86/fpu] lguest, x86: handle guest TS bit for lazy/ non-lazy " tip-bot for Suresh Siddha
2012-09-19 0:05 ` tip-bot for Suresh Siddha
2012-08-24 21:13 ` [PATCH 6/6] x86, fpu: use non-lazy fpu restore for processors supporting xsave Suresh Siddha
2012-08-24 22:17 ` [tip:x86/fpu] " tip-bot for Suresh Siddha
2012-08-24 21:33 ` [PATCH 0/6] x86, fpu: cleanups, introduce non-lazy FPU restore for xsave H. Peter Anvin
2012-08-25 18:34 ` Linus Torvalds
-- strict thread matches above, loose matches on Subject: below --
2012-09-10 18:11 [PATCH v2 0/5] eagerfpu patches for tip/x86/fpu Suresh Siddha
2012-09-10 18:11 ` [PATCH v2 1/5] x86, fpu: decouple non-lazy/eager fpu restore from xsave Suresh Siddha
2012-09-17 19:11 ` Pavel Machek
2012-09-19 0:07 ` [tip:x86/fpu] x86, fpu: decouple non-lazy/ eager " tip-bot for Suresh Siddha
2012-09-10 18:11 ` [PATCH v2 2/5] x86, fpu: enable eagerfpu by default for xsaveopt Suresh Siddha
2012-09-19 0:08 ` [tip:x86/fpu] " tip-bot for Suresh Siddha
2012-09-10 18:11 ` [PATCH v2 3/5] x86, fpu: move check_fpu() after alternative_instructions() Suresh Siddha
2012-09-19 0:06 ` [tip:x86/fpu] x86, fpu: use non-lazy fpu restore for processors supporting xsave tip-bot for Suresh Siddha
2012-09-10 18:11 ` [PATCH v2 4/5] x86, fpu: make eagerfpu= boot param tri-state Suresh Siddha
2012-09-19 0:09 ` [tip:x86/fpu] " tip-bot for Suresh Siddha
2012-09-10 18:11 ` [PATCH v2 5/5] x86, fpu: remove cpu_has_xmm check in the fx_finit() Suresh Siddha
2012-09-19 0:10 ` [tip:x86/fpu] " tip-bot for Suresh Siddha
2012-09-10 18:16 ` [PATCH v2 0/5] eagerfpu patches for tip/x86/fpu Borislav Petkov
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