mirror of https://lore.kernel.org/lkml/
 help / color / mirror / Atom feed
From: Ingo Molnar <mingo@kernel.org>
To: Rik van Riel <riel@redhat.com>
Cc: linux-kernel@vger.kernel.org,
	Andrew Morton <akpm@linux-foundation.org>,
	Andy Lutomirski <luto@amacapital.net>,
	Borislav Petkov <bp@alien8.de>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	Fenghua Yu <fenghua.yu@intel.com>,
	"H . Peter Anvin" <hpa@zytor.com>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Oleg Nesterov <oleg@redhat.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Yu-cheng Yu <yu-cheng.yu@intel.com>
Subject: Re: [PATCH 5/7] x86/fpu: Change fpu->fpregs_active users to fpu->fpstate_active
Date: Thu, 26 Jan 2017 16:53:07 +0100	[thread overview]
Message-ID: <20170126155307.GA26069@gmail.com> (raw)
In-Reply-To: <1485445549.15964.53.camel@redhat.com>


* Rik van Riel <riel@redhat.com> wrote:

> Let me go totally reimplement this whole project in a different way...

Note that I can still be convinced about complicating the FPU state machine as 
well if that ends up being the best approach for KVM - but it appears to me (from 
a very superficial look) that turning vCPU threads into no-FPU kthreads or 
representing the guest FPU state directly with the host FPU context would be even 
more beneficial, from the simplicity and KVM performance POV?

> At least I found some good FPU bugs and cleanups along the way.

Absolutely, and your efforts are much appreciated! This ptrace state handling 
madness that bit you on SkyLake was something I missed entirely.

Thanks,

	Ingo

  reply	other threads:[~2017-01-26 16:23 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-01-26 11:26 [PATCH 0/7] x86/fpu: Simplify the FPU state machine Ingo Molnar
2017-01-26 11:26 ` [PATCH 1/7] x86/fpu: Simplify the fpu->last_cpu logic and rename it to fpu->fpregs_cached Ingo Molnar
2017-01-26 14:23   ` Rik van Riel
2017-01-26 14:53     ` Ingo Molnar
2017-01-26 15:05       ` [PATCH] x86/fpu: Unify the naming of the FPU register cache validity flags Ingo Molnar
2017-01-26 15:31         ` Peter Zijlstra
2017-01-26 14:54   ` [PATCH 1/7] x86/fpu: Simplify the fpu->last_cpu logic and rename it to fpu->fpregs_cached Rik van Riel
2017-01-26 15:09     ` Ingo Molnar
2017-01-26 16:51     ` Andy Lutomirski
2017-01-26 11:26 ` [PATCH 2/7] x86/fpu: Simplify fpu->fpregs_active use Ingo Molnar
2017-01-26 16:30   ` Andy Lutomirski
2017-01-26 11:26 ` [PATCH 3/7] x86/fpu: Make the fpu state change in fpu__clear() scheduler-atomic Ingo Molnar
2017-01-26 11:26 ` [PATCH 4/7] x86/fpu: Split the state handling in fpu__drop() Ingo Molnar
2017-01-26 11:26 ` [PATCH 5/7] x86/fpu: Change fpu->fpregs_active users to fpu->fpstate_active Ingo Molnar
2017-01-26 14:44   ` Rik van Riel
2017-01-26 15:16     ` Ingo Molnar
2017-01-26 15:45       ` Rik van Riel
2017-01-26 15:53         ` Ingo Molnar [this message]
2017-01-26 17:00           ` Andy Lutomirski
2017-01-26 18:04             ` Rik van Riel
2017-01-26 11:26 ` [PATCH 6/7] x86/fpu: Decouple fpregs_activate()/fpregs_deactivate() from fpu->fpregs_active Ingo Molnar
2017-01-26 11:26 ` [PATCH 7/7] x86/fpu: Remove struct fpu::fpregs_active Ingo Molnar

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20170126155307.GA26069@gmail.com \
    --to=mingo@kernel.org \
    --cc=akpm@linux-foundation.org \
    --cc=bp@alien8.de \
    --cc=dave.hansen@linux.intel.com \
    --cc=fenghua.yu@intel.com \
    --cc=hpa@zytor.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=luto@amacapital.net \
    --cc=oleg@redhat.com \
    --cc=peterz@infradead.org \
    --cc=riel@redhat.com \
    --cc=tglx@linutronix.de \
    --cc=torvalds@linux-foundation.org \
    --cc=yu-cheng.yu@intel.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
Powered by JetHome