From: Martin Schwidefsky <schwidefsky@de.ibm.com>
To: Hugh Dickins <hugh@veritas.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Jeremy Fitzhardinge <jeremy@goop.org>,
Linux Memory Management List <linux-mm@kvack.org>,
Linux Kernel list <linux-kernel@vger.kernel.org>,
Nick Piggin <npiggin@suse.de>
Subject: Re: PTE access rules & abstraction
Date: Thu, 25 Sep 2008 00:17:00 +0200 [thread overview]
Message-ID: <1222294620.5968.4.camel@localhost> (raw)
In-Reply-To: <Pine.LNX.4.64.0809241919520.575@blonde.site>
On Wed, 2008-09-24 at 19:45 +0100, Hugh Dickins wrote:
> > I know s390 has different issues & constraints. Martin told me during
> > Plumbers that mprotect was probably also broken for him.
>
> Then I hope he will probably send Linus the fix.
>
> Though what we already have falls somewhat short of perfection,
> I've much more enthusiasm for fixing its bugs, than for any fancy
> redesign introducing its own bugs. Others have more stamina!
As far as I can tell the current code should work. It is not pretty
though, in particular the nasty pairing of flush_tlb_mm() with
ptep_set_wrprotect() and flush_tlb_range() with change_protection() is
fragile. For me the question is if we can find a sensible set of basic
primitives that work for all architectures in a performant way. This is
really hard..
--
blue skies,
Martin.
"Reality continues to ruin my life." - Calvin.
WARNING: multiple messages have this Message-ID (diff)
From: Martin Schwidefsky <schwidefsky@de.ibm.com>
To: Hugh Dickins <hugh@veritas.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Jeremy Fitzhardinge <jeremy@goop.org>,
Linux Memory Management List <linux-mm@kvack.org>,
Linux Kernel list <linux-kernel@vger.kernel.org>,
Nick Piggin <npiggin@suse.de>
Subject: Re: PTE access rules & abstraction
Date: Thu, 25 Sep 2008 00:17:00 +0200 [thread overview]
Message-ID: <1222294620.5968.4.camel@localhost> (raw)
In-Reply-To: <Pine.LNX.4.64.0809241919520.575@blonde.site>
On Wed, 2008-09-24 at 19:45 +0100, Hugh Dickins wrote:
> > I know s390 has different issues & constraints. Martin told me during
> > Plumbers that mprotect was probably also broken for him.
>
> Then I hope he will probably send Linus the fix.
>
> Though what we already have falls somewhat short of perfection,
> I've much more enthusiasm for fixing its bugs, than for any fancy
> redesign introducing its own bugs. Others have more stamina!
As far as I can tell the current code should work. It is not pretty
though, in particular the nasty pairing of flush_tlb_mm() with
ptep_set_wrprotect() and flush_tlb_range() with change_protection() is
fragile. For me the question is if we can find a sensible set of basic
primitives that work for all architectures in a performant way. This is
really hard..
--
blue skies,
Martin.
"Reality continues to ruin my life." - Calvin.
--
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next prev parent reply other threads:[~2008-09-24 22:21 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-09-19 17:42 PTE access rules & abstraction Benjamin Herrenschmidt
2008-09-19 17:42 ` Benjamin Herrenschmidt
2008-09-22 6:22 ` Jeremy Fitzhardinge
2008-09-22 6:22 ` Jeremy Fitzhardinge
2008-09-22 21:05 ` Benjamin Herrenschmidt
2008-09-22 21:05 ` Benjamin Herrenschmidt
2008-09-23 3:10 ` Nick Piggin
2008-09-23 3:10 ` Nick Piggin
2008-09-23 3:16 ` David Miller
2008-09-23 3:16 ` David Miller, Nick Piggin
2008-09-23 5:35 ` Benjamin Herrenschmidt
2008-09-23 5:35 ` Benjamin Herrenschmidt
2008-09-23 6:18 ` Nick Piggin
2008-09-23 6:18 ` Nick Piggin
2008-09-23 5:31 ` Benjamin Herrenschmidt
2008-09-23 5:31 ` Benjamin Herrenschmidt
2008-09-23 6:13 ` Jeremy Fitzhardinge
2008-09-23 6:13 ` Jeremy Fitzhardinge
2008-09-23 6:49 ` Benjamin Herrenschmidt
2008-09-23 6:49 ` Benjamin Herrenschmidt
2008-09-23 9:50 ` Nick Piggin
2008-09-23 9:50 ` Nick Piggin
2008-09-23 11:54 ` peter
2008-09-23 11:54 ` peter
2008-09-24 18:45 ` Hugh Dickins
2008-09-24 18:45 ` Hugh Dickins
2008-09-24 21:20 ` Benjamin Herrenschmidt
2008-09-24 21:20 ` Benjamin Herrenschmidt
2008-09-24 21:57 ` Jeremy Fitzhardinge
2008-09-24 21:57 ` Jeremy Fitzhardinge
2008-09-24 22:07 ` Benjamin Herrenschmidt
2008-09-24 22:07 ` Benjamin Herrenschmidt
2008-09-24 22:43 ` Jeremy Fitzhardinge
2008-09-24 22:43 ` Jeremy Fitzhardinge
2008-09-24 22:53 ` Benjamin Herrenschmidt
2008-09-24 22:53 ` Benjamin Herrenschmidt
2008-09-24 23:55 ` Hugh Dickins
2008-09-24 23:55 ` Hugh Dickins
2008-09-25 1:04 ` Benjamin Herrenschmidt
2008-09-25 1:04 ` Benjamin Herrenschmidt
2008-09-25 18:15 ` Jeremy Fitzhardinge
2008-09-25 18:15 ` Jeremy Fitzhardinge
2008-09-25 21:44 ` Benjamin Herrenschmidt
2008-09-25 21:44 ` Benjamin Herrenschmidt
2008-09-25 22:27 ` Jeremy Fitzhardinge
2008-09-25 22:27 ` Jeremy Fitzhardinge
2008-09-25 23:02 ` Benjamin Herrenschmidt
2008-09-25 23:02 ` Benjamin Herrenschmidt
2008-09-24 22:17 ` Martin Schwidefsky [this message]
2008-09-24 22:17 ` Martin Schwidefsky
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