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Date: Sat, 14 Mar 2015 11:55:02 +0100
From: Borislav Petkov <bp@suse.de>
To: Oleg Nesterov <oleg@redhat.com>
Cc: Dave Hansen <dave.hansen@intel.com>, Ingo Molnar <mingo@kernel.org>,
        Andy Lutomirski <luto@amacapital.net>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Pekka Riikonen <priikone@iki.fi>, Rik van Riel <riel@redhat.com>,
        Suresh Siddha <sbsiddha@gmail.com>,
        LKML <linux-kernel@vger.kernel.org>,
        "Yu, Fenghua" <fenghua.yu@intel.com>,
        Quentin Casasnovas <quentin.casasnovas@oracle.com>
Subject: Re: [PATCH v2 4/4] x86/fpu: don't abuse drop_init_fpu() in
 flush_thread()
Message-ID: <20150314105502.GB3114@pd.tnic>
References: <54F74F59.5070107@intel.com>
 <20150311173346.GB5032@redhat.com>
 <20150311173507.GF5032@redhat.com>
 <20150313173030.GA31217@redhat.com>
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On Fri, Mar 13, 2015 at 06:30:30PM +0100, Oleg Nesterov wrote:
> flush_thread() -> drop_init_fpu() is suboptimal and confusing. It does
> drop_fpu() or restore_init_xstate() depending on !use_eager_fpu(). But
> flush_thread() too checks eagerfpu right after that, and if it is true
> then restore_init_xstate() just burns CPU for no reason. We are going to
> load init_xstate_buf again after we set used_math/user_has_fpu, until
> then the FPU state can't survive after switch_to().
> 
> Remove it, and change the "if (!use_eager_fpu())" to call drop_fpu().
> While at it, clean up the tsk/current usage.
> 
> Signed-off-by: Oleg Nesterov <oleg@redhat.com>

Thanks, applied.

Did a trivial cleanup ontop, see reply to this message.

-- 
Regards/Gruss,
    Boris.

ECO tip #101: Trim your mails when you reply.
--