From: "Paul E. McKenney" <paulmck@linux.ibm.com>
To: Will Deacon <will.deacon@arm.com>
Cc: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Arnd Bergmann <arnd@arndb.de>,
Peter Zijlstra <peterz@infradead.org>,
Andrea Parri <andrea.parri@amarulasolutions.com>,
Daniel Lustig <dlustig@nvidia.com>,
David Howells <dhowells@redhat.com>,
Alan Stern <stern@rowland.harvard.edu>,
Linus Torvalds <torvalds@linux-foundation.org>
Subject: Re: [RFC PATCH] docs/memory-barriers.txt: Rewrite "KERNEL I/O BARRIER EFFECTS" section
Date: Tue, 12 Feb 2019 11:24:05 -0800 [thread overview]
Message-ID: <20190212192405.GU4240@linux.ibm.com> (raw)
In-Reply-To: <20190212184354.GC20961@fuggles.cambridge.arm.com>
On Tue, Feb 12, 2019 at 06:43:54PM +0000, Will Deacon wrote:
> On Mon, Feb 11, 2019 at 12:22:18PM -0800, Paul E. McKenney wrote:
> > On Mon, Feb 11, 2019 at 05:29:48PM +0000, Will Deacon wrote:
> > > The "KERNEL I/O BARRIER EFFECTS" section of memory-barriers.txt is vague,
> > > x86-centric, out-of-date, incomplete and demonstrably incorrect in places.
> > > This is largely because I/O ordering is a horrible can of worms, but also
> > > because the document has stagnated as our understanding has evolved.
> > >
> > > Attempt to address some of that, by rewriting the section based on
> > > recent(-ish) discussions with Arnd, BenH and others. Maybe one day we'll
> > > find a way to formalise this stuff, but for now let's at least try to
> > > make the English easier to understand.
> > >
> > > Cc: "Paul E. McKenney" <paulmck@linux.ibm.com>
> > > Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> > > Cc: Arnd Bergmann <arnd@arndb.de>
> > > Cc: Peter Zijlstra <peterz@infradead.org>
> > > Cc: Andrea Parri <andrea.parri@amarulasolutions.com>
> > > Cc: Daniel Lustig <dlustig@nvidia.com>
> > > Cc: David Howells <dhowells@redhat.com>
> > > Cc: Alan Stern <stern@rowland.harvard.edu>
> > > cc: Linus Torvalds <torvalds@linux-foundation.org>
> > > Signed-off-by: Will Deacon <will.deacon@arm.com>
> >
> > Hello, Will,
> >
> > The intent is to replace commit 3f305018dcf3 ("docs/memory-barriers.txt:
> > Enforce heavy ordering for port I/O accesses"), correct? Either way is
> > fine, just guessing based on the conflicts when applying this one. ;-)
>
> Yup, I decided to abandon the old patch:
>
> http://lkml.kernel.org/r/20190211153043.GC32385@fuggles.cambridge.arm.com
Got it, and thank you for the reminder!
Thanx, Paul
next prev parent reply other threads:[~2019-02-12 19:24 UTC|newest]
Thread overview: 54+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-11 17:29 [RFC PATCH] docs/memory-barriers.txt: Rewrite "KERNEL I/O BARRIER EFFECTS" section Will Deacon
2019-02-11 17:29 ` Will Deacon
2019-02-11 20:22 ` Paul E. McKenney
2019-02-11 20:22 ` Paul E. McKenney
2019-02-12 18:43 ` Will Deacon
2019-02-12 18:43 ` Will Deacon
2019-02-12 19:24 ` Paul E. McKenney [this message]
2019-02-12 19:24 ` Paul E. McKenney
2019-02-11 22:34 ` Linus Torvalds
2019-02-11 22:34 ` Linus Torvalds
2019-02-12 4:01 ` Benjamin Herrenschmidt
2019-02-12 4:01 ` Benjamin Herrenschmidt
2019-02-13 17:20 ` Will Deacon
2019-02-13 17:20 ` Will Deacon
2019-02-13 18:27 ` Linus Torvalds
2019-02-13 18:27 ` Linus Torvalds
2019-02-13 18:33 ` Peter Zijlstra
2019-02-13 18:33 ` Peter Zijlstra
2019-02-13 18:43 ` Luck, Tony
2019-02-13 18:43 ` Luck, Tony
2019-02-13 19:31 ` Paul E. McKenney
2019-02-13 19:31 ` Paul E. McKenney
2019-02-18 16:50 ` Will Deacon
2019-02-18 16:50 ` Will Deacon
2019-02-19 16:13 ` Will Deacon
2019-02-19 16:13 ` Will Deacon
2019-02-21 6:22 ` Michael Ellerman
2019-02-21 6:22 ` Michael Ellerman
2019-02-22 17:38 ` Will Deacon
2019-02-22 17:38 ` Will Deacon
2019-02-12 13:03 ` Arnd Bergmann
2019-02-12 13:03 ` Arnd Bergmann
2019-02-18 16:29 ` Will Deacon
2019-02-18 16:29 ` Will Deacon
2019-02-18 16:59 ` Arnd Bergmann
2019-02-18 16:59 ` Arnd Bergmann
2019-02-18 17:56 ` Will Deacon
2019-02-18 17:56 ` Will Deacon
2019-02-18 20:37 ` Arnd Bergmann
2019-02-18 20:37 ` Arnd Bergmann
2019-02-19 10:27 ` Thomas Petazzoni
2019-02-19 10:27 ` Thomas Petazzoni
2019-02-19 11:31 ` Arnd Bergmann
2019-02-19 11:31 ` Arnd Bergmann
2019-02-19 11:36 ` Will Deacon
2019-02-19 11:36 ` Will Deacon
2019-02-19 13:01 ` Arnd Bergmann
2019-02-19 13:01 ` Arnd Bergmann
2019-02-19 13:20 ` Will Deacon
2019-02-19 13:20 ` Will Deacon
2019-02-19 13:45 ` Arnd Bergmann
2019-02-19 13:45 ` Arnd Bergmann
2019-02-19 11:34 ` Will Deacon
2019-02-19 11:34 ` Will Deacon
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