From: Borislav Petkov <bp@amd64.org>
To: Andy Lutomirski <luto@MIT.EDU>
Cc: "x86@kernel.org" <x86@kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Ingo Molnar <mingo@elte.hu>, Andi Kleen <andi@firstfloor.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
"David S. Miller" <davem@davemloft.net>,
Eric Dumazet <eric.dumazet@gmail.com>,
Peter Zijlstra <a.p.zijlstra@chello.nl>,
Thomas Gleixner <tglx@linutronix.de>,
Borislav Petkov <bp@amd64.org>
Subject: Re: [PATCH v4 1/6] x86-64: Clean up vdso/kernel shared variables
Date: Mon, 16 May 2011 19:23:38 +0200 [thread overview]
Message-ID: <20110516172338.GC22383@aftab> (raw)
In-Reply-To: <5062fb3d104744b00b45afec76bf78e504785370.1305560561.git.luto@mit.edu>
On Mon, May 16, 2011 at 12:00:58PM -0400, Andy Lutomirski wrote:
> Variables that are shared between the vdso and the kernel are
> currently a bit of a mess. They are each defined with their own
> magic, they are accessed differently in the kernel, the vsyscall page,
> and the vdso, and one of them (vsyscall_clock) doesn't even really
> exist.
>
> This changes them all to use a common mechanism. All of them are
> delcared in vvar.h with a fixed address (validated by the linker
> script). In the kernel (as before), they look like ordinary
> read-write variables. In the vsyscall page and the vdso, they are
> accessed through a new macro VVAR, which gives read-only access.
>
> The vdso is now loaded verbatim into memory without any fixups. As a
> side bonus, access from the vdso is faster because a level of
> indirection is removed.
>
> While we're at it, pack jiffies and vgetcpu_mode into the same
> cacheline.
How about
Signed-off-by:...
or you don't wanna? :)
> ---
> arch/x86/include/asm/vdso.h | 14 ----------
> arch/x86/include/asm/vgtod.h | 2 -
> arch/x86/include/asm/vsyscall.h | 12 +-------
> arch/x86/include/asm/vvar.h | 52 +++++++++++++++++++++++++++++++++++++++
> arch/x86/kernel/time.c | 2 +-
> arch/x86/kernel/tsc.c | 4 +-
> arch/x86/kernel/vmlinux.lds.S | 34 ++++++++-----------------
> arch/x86/kernel/vsyscall_64.c | 46 +++++++++++++++-------------------
> arch/x86/vdso/Makefile | 2 +-
> arch/x86/vdso/vclock_gettime.c | 3 +-
> arch/x86/vdso/vdso.lds.S | 7 -----
> arch/x86/vdso/vextern.h | 16 ------------
> arch/x86/vdso/vgetcpu.c | 3 +-
> arch/x86/vdso/vma.c | 27 --------------------
> arch/x86/vdso/vvar.c | 12 ---------
> 15 files changed, 91 insertions(+), 145 deletions(-)
> create mode 100644 arch/x86/include/asm/vvar.h
> delete mode 100644 arch/x86/vdso/vextern.h
> delete mode 100644 arch/x86/vdso/vvar.c
>
--
Regards/Gruss,
Boris.
Advanced Micro Devices GmbH
Einsteinring 24, 85609 Dornach
General Managers: Alberto Bozzo, Andrew Bowd
Registration: Dornach, Gemeinde Aschheim, Landkreis Muenchen
Registergericht Muenchen, HRB Nr. 43632
next prev parent reply other threads:[~2011-05-16 17:24 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-05-16 16:00 [PATCH v4 0/6] Micro-optimize vclock_gettime Andy Lutomirski
2011-05-16 16:00 ` [PATCH v4 1/6] x86-64: Clean up vdso/kernel shared variables Andy Lutomirski
2011-05-16 17:23 ` Borislav Petkov [this message]
2011-05-16 17:34 ` Andrew Lutomirski
2011-05-16 16:00 ` [PATCH v4 2/6] x86-64: Remove unnecessary barrier in vread_tsc Andy Lutomirski
2011-05-16 16:01 ` [PATCH v4 3/6] x86-64: Don't generate cmov " Andy Lutomirski
2011-05-16 16:01 ` [PATCH v4 4/6] x86-64: vclock_gettime(CLOCK_MONOTONIC) can't ever see nsec < 0 Andy Lutomirski
2011-05-16 16:01 ` [PATCH v4 5/6] x86-64: Move vread_tsc into a new file with sensible options Andy Lutomirski
2011-05-16 16:01 ` [PATCH v4 6/6] x86-64: Turn off -pg and turn on -foptimize-sibling-calls for vDSO Andy Lutomirski
2011-05-16 16:09 ` [PATCH v4 0/6] Micro-optimize vclock_gettime Andi Kleen
2011-05-16 16:25 ` Thomas Gleixner
2011-05-16 16:49 ` Andi Kleen
2011-05-16 17:05 ` Andrew Lutomirski
2011-05-16 20:22 ` Andi Kleen
2011-05-16 21:28 ` Andrew Lutomirski
2011-05-16 21:53 ` Thomas Gleixner
2011-05-16 22:17 ` Andrew Lutomirski
2011-05-16 22:40 ` Thomas Gleixner
2011-05-17 8:00 ` Ingo Molnar
2011-05-17 11:11 ` Andrew Lutomirski
2011-05-17 11:36 ` Ingo Molnar
2011-05-17 18:31 ` Andy Lutomirski
2011-05-17 19:27 ` Ingo Molnar
2011-05-17 21:31 ` Andi Kleen
2011-05-17 22:59 ` Thomas Gleixner
2011-05-18 3:18 ` Andrew Lutomirski
2011-05-18 7:30 ` Thomas Gleixner
2011-05-18 8:31 ` Ingo Molnar
2011-05-18 11:30 ` Andrew Lutomirski
2011-05-18 12:10 ` Ingo Molnar
2011-05-17 7:56 ` Ingo Molnar
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