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()
Date: Sat, 14 Mar 2015 11:55:02 +0100 [thread overview]
Message-ID: <20150314105502.GB3114@pd.tnic> (raw)
In-Reply-To: <20150313173030.GA31217@redhat.com>
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.
--
next prev parent reply other threads:[~2015-03-14 10:56 UTC|newest]
Thread overview: 126+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-03-04 18:30 Oops with tip/x86/fpu Dave Hansen
2015-03-04 19:06 ` Oleg Nesterov
2015-03-04 19:12 ` Dave Hansen
2015-03-04 20:06 ` Borislav Petkov
2015-03-05 15:14 ` Oleg Nesterov
[not found] ` <20150305182203.GA4203@redhat.com>
2015-03-05 18:34 ` Dave Hansen
2015-03-05 18:46 ` Oleg Nesterov
2015-03-05 18:41 ` Dave Hansen
2015-03-26 22:37 ` Yu, Fenghua
2015-03-26 22:43 ` Dave Hansen
2015-03-26 22:48 ` Yu, Fenghua
2015-03-27 7:30 ` Quentin Casasnovas
2015-03-27 19:06 ` Oleg Nesterov
2015-03-05 8:38 ` Quentin Casasnovas
2015-03-05 15:13 ` Oleg Nesterov
2015-03-05 18:42 ` Borislav Petkov
2015-03-05 22:16 ` Dave Hansen
2015-03-05 19:51 ` [PATCH 0/1] x86/fpu: math_state_restore() should not blindly disable irqs Oleg Nesterov
2015-03-05 19:51 ` [PATCH 1/1] " Oleg Nesterov
2015-03-05 20:11 ` Ingo Molnar
2015-03-05 21:25 ` Oleg Nesterov
2015-03-06 7:58 ` Ingo Molnar
2015-03-06 13:26 ` Oleg Nesterov
2015-03-06 13:39 ` Oleg Nesterov
2015-03-06 13:46 ` Ingo Molnar
2015-03-06 14:01 ` Oleg Nesterov
2015-03-06 14:17 ` Oleg Nesterov
2015-03-06 15:00 ` David Vrabel
2015-03-06 15:36 ` Oleg Nesterov
2015-03-06 16:15 ` David Vrabel
2015-03-06 16:31 ` Oleg Nesterov
2015-03-06 17:33 ` Linus Torvalds
2015-03-06 18:15 ` Oleg Nesterov
2015-03-06 19:23 ` Andy Lutomirski
2015-03-06 22:00 ` Linus Torvalds
2015-03-06 22:28 ` Andy Lutomirski
2015-03-07 10:36 ` Ingo Molnar
2015-03-07 20:11 ` Linus Torvalds
2015-03-08 8:55 ` Ingo Molnar
2015-03-08 11:38 ` Ingo Molnar
2015-03-08 13:59 ` Andy Lutomirski
2015-03-08 14:38 ` Andy Lutomirski
2015-03-07 10:32 ` Ingo Molnar
2015-03-07 15:38 ` [PATCH 0/1] x86/fpu: x86/fpu: avoid math_state_restore() without used_math() in __restore_xstate_sig() Oleg Nesterov
2015-03-07 15:38 ` [PATCH 1/1] " Oleg Nesterov
2015-03-09 14:07 ` Borislav Petkov
2015-03-09 14:34 ` Oleg Nesterov
2015-03-09 15:18 ` Borislav Petkov
2015-03-09 16:24 ` Oleg Nesterov
2015-03-09 16:53 ` Borislav Petkov
2015-03-09 17:05 ` Oleg Nesterov
2015-03-09 17:23 ` Borislav Petkov
2015-03-16 12:07 ` [tip:x86/urgent] x86/fpu: Avoid " tip-bot for Oleg Nesterov
2015-03-05 20:35 ` [PATCH 0/1] x86/fpu: math_state_restore() should not blindly disable irqs Oleg Nesterov
2015-03-09 17:10 ` [PATCH] x86/fpu: drop_fpu() should not assume that tsk == current Oleg Nesterov
2015-03-09 17:36 ` Rik van Riel
2015-03-09 17:48 ` Borislav Petkov
2015-03-09 18:06 ` Oleg Nesterov
2015-03-09 18:10 ` Borislav Petkov
2015-03-16 12:07 ` [tip:x86/urgent] x86/fpu: Drop_fpu() should not assume that tsk equals current tip-bot for Oleg Nesterov
2015-03-11 17:33 ` [PATCH 0/4] x86/fpu: avoid math_state_restore() on kthread exec Oleg Nesterov
2015-03-11 17:34 ` [PATCH 1/4] x86/fpu: document user_fpu_begin() Oleg Nesterov
2015-03-13 9:47 ` Borislav Petkov
2015-03-13 14:34 ` Oleg Nesterov
2015-03-23 12:20 ` [tip:x86/fpu] x86/fpu: Document user_fpu_begin() tip-bot for Oleg Nesterov
2015-03-11 17:34 ` [PATCH 2/4] x86/fpu: introduce restore_init_xstate() Oleg Nesterov
2015-03-13 10:34 ` Borislav Petkov
2015-03-13 14:39 ` Oleg Nesterov
2015-03-13 15:20 ` Borislav Petkov
2015-03-16 19:05 ` Rik van Riel
2015-03-23 12:20 ` [tip:x86/fpu] x86/fpu: Introduce restore_init_xstate() tip-bot for Oleg Nesterov
2015-03-11 17:34 ` [PATCH 3/4] x86/fpu: use restore_init_xstate() instead of math_state_restore() on kthread exec Oleg Nesterov
2015-03-13 10:48 ` Borislav Petkov
2015-03-13 14:45 ` Oleg Nesterov
2015-03-13 15:51 ` Borislav Petkov
2015-03-23 12:21 ` [tip:x86/fpu] x86/fpu: Use " tip-bot for Oleg Nesterov
2015-03-11 17:35 ` [PATCH 4/4] x86/fpu: don't abuse drop_init_fpu() in flush_thread() Oleg Nesterov
2015-03-13 10:52 ` Borislav Petkov
2015-03-13 14:55 ` Oleg Nesterov
2015-03-13 16:19 ` Borislav Petkov
2015-03-13 16:26 ` Oleg Nesterov
2015-03-13 19:27 ` Borislav Petkov
2015-03-14 14:48 ` Oleg Nesterov
2015-03-15 17:36 ` Borislav Petkov
2015-03-15 18:16 ` Oleg Nesterov
2015-03-15 18:50 ` Borislav Petkov
2015-03-15 20:04 ` Oleg Nesterov
2015-03-15 20:38 ` Borislav Petkov
2015-03-16 9:35 ` Borislav Petkov
2015-03-16 10:28 ` Ingo Molnar
2015-03-16 14:39 ` Oleg Nesterov
2015-03-16 15:26 ` Borislav Petkov
2015-03-16 15:34 ` Andy Lutomirski
2015-03-16 15:35 ` Borislav Petkov
2015-03-13 17:30 ` [PATCH v2 " Oleg Nesterov
2015-03-14 10:55 ` Borislav Petkov [this message]
2015-03-14 10:57 ` [PATCH] x86/fpu: Fold __drop_fpu() into its sole user Borislav Petkov
2015-03-14 15:15 ` Oleg Nesterov
2015-03-16 10:27 ` Ingo Molnar
2015-03-23 12:21 ` [tip:x86/fpu] x86/fpu: Don't abuse drop_init_fpu() in flush_thread() tip-bot for Oleg Nesterov
2015-03-13 18:26 ` [PATCH 0/1] x86/cpu: don't allocate fpu->state for swapper/0 Oleg Nesterov
2015-03-13 18:27 ` [PATCH 1/1] " Oleg Nesterov
2015-03-16 10:18 ` Borislav Petkov
2015-03-23 12:22 ` [tip:x86/fpu] x86/fpu: Don't " tip-bot for Oleg Nesterov
2015-03-14 11:16 ` [PATCH 0/1] x86/cpu: don't " Borislav Petkov
2015-03-14 15:13 ` [PATCH 0/1] x86/cpu: kill eager_fpu_init_bp() Oleg Nesterov
2015-03-14 15:13 ` [PATCH 1/1] " Oleg Nesterov
2015-03-16 12:44 ` Borislav Petkov
2015-03-23 12:22 ` [tip:x86/fpu] x86/fpu: Kill eager_fpu_init_bp() tip-bot for Oleg Nesterov
2015-03-15 16:49 ` [PATCH RFC 0/2] x86/fpu: avoid "xstate_fault" in xsave_user/xrestore_user Oleg Nesterov
2015-03-15 16:50 ` [PATCH RFC 1/2] x86: introduce __user_insn() and __check_insn() Oleg Nesterov
2015-03-15 16:50 ` [PATCH RFC 2/2] x86/fpu: change xsave_user() and xrestore_user() to use __user_insn() Oleg Nesterov
2015-03-16 22:43 ` Quentin Casasnovas
2015-03-17 9:35 ` Borislav Petkov
2015-03-16 14:36 ` [PATCH RFC 0/2] x86/fpu: avoid "xstate_fault" in xsave_user/xrestore_user Borislav Petkov
2015-03-16 14:57 ` Oleg Nesterov
2015-03-16 17:58 ` Borislav Petkov
2015-03-16 22:37 ` Quentin Casasnovas
2015-03-17 9:47 ` Borislav Petkov
2015-03-17 10:00 ` Quentin Casasnovas
2015-03-17 11:20 ` Borislav Petkov
2015-03-17 11:36 ` Quentin Casasnovas
2015-03-17 12:07 ` Borislav Petkov
2015-03-18 9:06 ` Quentin Casasnovas
2015-03-18 9:53 ` Borislav Petkov
2015-03-17 10:07 ` Quentin Casasnovas
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