On Mon, Feb 26, 2018 at 09:00:43AM -0800, Linus Torvalds wrote:
> On Mon, Feb 26, 2018 at 8:24 AM, Will Deacon wrote:
> >
> > Strictly speaking, that's not what we've got implemented on arm64: only
> > the read part of the RmW has Acquire semantics, but there is a total
> > order on the lock/unloc
On 3/1/2018 1:54 PM, Palmer Dabbelt wrote:
> On Thu, 01 Mar 2018 07:11:41 PST (-0800), parri.and...@gmail.com wrote:
>> Hi Daniel,
>>
>> On Thu, Feb 22, 2018 at 11:47:57AM -0800, Daniel Lustig wrote:
>>> On 2/22/2018 10:27 AM, Peter Zijlstra wrote:
>>> > On Thu, Feb 22, 2018 at 10:13:17AM -0800, Pa
On Thu, 01 Mar 2018 07:11:41 PST (-0800), parri.and...@gmail.com wrote:
Hi Daniel,
On Thu, Feb 22, 2018 at 11:47:57AM -0800, Daniel Lustig wrote:
On 2/22/2018 10:27 AM, Peter Zijlstra wrote:
> On Thu, Feb 22, 2018 at 10:13:17AM -0800, Paul E. McKenney wrote:
>> So we have something that is not
Hi Daniel,
On Thu, Feb 22, 2018 at 11:47:57AM -0800, Daniel Lustig wrote:
> On 2/22/2018 10:27 AM, Peter Zijlstra wrote:
> > On Thu, Feb 22, 2018 at 10:13:17AM -0800, Paul E. McKenney wrote:
> >> So we have something that is not all that rare in the Linux kernel
> >> community, namely two conflict
On Tue, Feb 27, 2018 at 01:06:35PM +0800, Boqun Feng wrote:
> On Mon, Feb 26, 2018 at 04:24:27PM +, Will Deacon wrote:
> > On Mon, Feb 26, 2018 at 08:06:59AM -0800, Linus Torvalds wrote:
> > > On Mon, Feb 26, 2018 at 6:21 AM, Luc Maranget
> > > wrote:
> > > >
> > > > That is, locks are not im
On Mon, Feb 26, 2018 at 04:24:27PM +, Will Deacon wrote:
> On Mon, Feb 26, 2018 at 08:06:59AM -0800, Linus Torvalds wrote:
> > On Mon, Feb 26, 2018 at 6:21 AM, Luc Maranget wrote:
> > >
> > > That is, locks are not implemented from more basic primitive but are
> > > specified.
> > > The speci
On Mon, Feb 26, 2018 at 09:00:43AM -0800, Linus Torvalds wrote:
> On Mon, Feb 26, 2018 at 8:24 AM, Will Deacon wrote:
> >
> > Strictly speaking, that's not what we've got implemented on arm64: only
> > the read part of the RmW has Acquire semantics, but there is a total
> > order on the lock/unloc
On Mon, Feb 26, 2018 at 8:24 AM, Will Deacon wrote:
>
> Strictly speaking, that's not what we've got implemented on arm64: only
> the read part of the RmW has Acquire semantics, but there is a total
> order on the lock/unlock operations for the lock.
Hmm.
I thought we had exactly that bug on som
On Mon, Feb 26, 2018 at 08:06:59AM -0800, Linus Torvalds wrote:
> On Mon, Feb 26, 2018 at 6:21 AM, Luc Maranget wrote:
> >
> > That is, locks are not implemented from more basic primitive but are
> > specified.
> > The specification can be described as behaving that way:
> > - A lock behaves as
On Mon, Feb 26, 2018 at 6:21 AM, Luc Maranget wrote:
>
> That is, locks are not implemented from more basic primitive but are
> specified.
> The specification can be described as behaving that way:
> - A lock behaves as a read-modify-write. the read behaving as a read-acquire
This is wrong, or
> On 2/22/2018 10:27 AM, Peter Zijlstra wrote:
> > On Thu, Feb 22, 2018 at 10:13:17AM -0800, Paul E. McKenney wrote:
> >> So we have something that is not all that rare in the Linux kernel
> >> community, namely two conflicting more-or-less concurrent changes.
> >> This clearly needs to be resolved
On Thu, Feb 22, 2018 at 11:47:57AM -0800, Daniel Lustig wrote:
> On 2/22/2018 10:27 AM, Peter Zijlstra wrote:
> > On Thu, Feb 22, 2018 at 10:13:17AM -0800, Paul E. McKenney wrote:
> >> So we have something that is not all that rare in the Linux kernel
> >> community, namely two conflicting more-or-
On Thu, Feb 22, 2018 at 11:47:57AM -0800, Daniel Lustig wrote:
> On 2/22/2018 10:27 AM, Peter Zijlstra wrote:
> > On Thu, Feb 22, 2018 at 10:13:17AM -0800, Paul E. McKenney wrote:
> >> So we have something that is not all that rare in the Linux kernel
> >> community, namely two conflicting more-or-
On Thu, Feb 22, 2018 at 07:27:17PM +0100, Peter Zijlstra wrote:
> On Thu, Feb 22, 2018 at 10:13:17AM -0800, Paul E. McKenney wrote:
> > So we have something that is not all that rare in the Linux kernel
> > community, namely two conflicting more-or-less concurrent changes.
> > This clearly needs to
On 2/22/2018 10:27 AM, Peter Zijlstra wrote:
> On Thu, Feb 22, 2018 at 10:13:17AM -0800, Paul E. McKenney wrote:
>> So we have something that is not all that rare in the Linux kernel
>> community, namely two conflicting more-or-less concurrent changes.
>> This clearly needs to be resolved, either b
On Thu, Feb 22, 2018 at 10:13:17AM -0800, Paul E. McKenney wrote:
> So we have something that is not all that rare in the Linux kernel
> community, namely two conflicting more-or-less concurrent changes.
> This clearly needs to be resolved, either by us not strengthening the
> Linux-kernel memory m
On Thu, Feb 22, 2018 at 09:27:09AM -0800, Daniel Lustig wrote:
> On 2/22/2018 6:12 AM, Andrea Parri wrote:
> > On Thu, Feb 22, 2018 at 02:40:04PM +0100, Peter Zijlstra wrote:
> >> On Thu, Feb 22, 2018 at 01:19:50PM +0100, Andrea Parri wrote:
> >>
> >>> C unlock-lock-read-ordering
> >>>
> >>> {}
> >
On Thu, Feb 22, 2018 at 09:27:09AM -0800, Daniel Lustig wrote:
> On 2/22/2018 6:12 AM, Andrea Parri wrote:
> > On Thu, Feb 22, 2018 at 02:40:04PM +0100, Peter Zijlstra wrote:
> >> On Thu, Feb 22, 2018 at 01:19:50PM +0100, Andrea Parri wrote:
> >>
> >>> C unlock-lock-read-ordering
> >>>
> >>> {}
> >
On 2/22/2018 6:12 AM, Andrea Parri wrote:
> On Thu, Feb 22, 2018 at 02:40:04PM +0100, Peter Zijlstra wrote:
>> On Thu, Feb 22, 2018 at 01:19:50PM +0100, Andrea Parri wrote:
>>
>>> C unlock-lock-read-ordering
>>>
>>> {}
>>> /* s initially owned by P1 */
>>>
>>> P0(int *x, int *y)
>>> {
>>> WRITE
On Thu, Feb 22, 2018 at 02:40:04PM +0100, Peter Zijlstra wrote:
> On Thu, Feb 22, 2018 at 01:19:50PM +0100, Andrea Parri wrote:
>
> > C unlock-lock-read-ordering
> >
> > {}
> > /* s initially owned by P1 */
> >
> > P0(int *x, int *y)
> > {
> > WRITE_ONCE(*x, 1);
> > smp_wmb();
> > WR
On Thu, Feb 22, 2018 at 01:19:50PM +0100, Andrea Parri wrote:
> C unlock-lock-read-ordering
>
> {}
> /* s initially owned by P1 */
>
> P0(int *x, int *y)
> {
> WRITE_ONCE(*x, 1);
> smp_wmb();
> WRITE_ONCE(*y, 1);
> }
>
> P1(int *x, int *y, spinlock_t *s)
> {
> int r0;
>
On Thu, Feb 22, 2018 at 01:19:50PM +0100, Andrea Parri wrote:
> The LKMM defines certain memory ordering constraints for spin_lock(),
> spin_unlock() and other primitives that the kernel developer can rely
> on; unfortunately, some of these constraints are not currently met by
> the RISC-V implemen
22 matches
Mail list logo
