Re: [PATCH v2 2/2] riscv/atomic: Strengthen implementations with fences

2018-03-13 Thread Luc Maranget
> On Fri, Mar 09, 2018 at 04:21:37PM -0800, Daniel Lustig wrote: > > On 3/9/2018 2:57 PM, Palmer Dabbelt wrote: > > > On Fri, 09 Mar 2018 13:30:08 PST (-0800), parri.and...@gmail.com wrote: > > >> On Fri, Mar 09, 2018 at 10:54:27AM -0800, Palmer Dabbelt wrote: > > >>> On Fri, 09 Mar 2018 10:36:44 P

Re: [PATCH v2 2/2] riscv/atomic: Strengthen implementations with fences

2018-03-11 Thread Boqun Feng
On Fri, Mar 09, 2018 at 04:21:37PM -0800, Daniel Lustig wrote: > On 3/9/2018 2:57 PM, Palmer Dabbelt wrote: > > On Fri, 09 Mar 2018 13:30:08 PST (-0800), parri.and...@gmail.com wrote: > >> On Fri, Mar 09, 2018 at 10:54:27AM -0800, Palmer Dabbelt wrote: > >>> On Fri, 09 Mar 2018 10:36:44 PST (-0800)

Re: [PATCH v2 2/2] riscv/atomic: Strengthen implementations with fences

2018-03-10 Thread Andrea Parri
On Fri, Mar 09, 2018 at 04:21:37PM -0800, Daniel Lustig wrote: > On 3/9/2018 2:57 PM, Palmer Dabbelt wrote: > > On Fri, 09 Mar 2018 13:30:08 PST (-0800), parri.and...@gmail.com wrote: > >> On Fri, Mar 09, 2018 at 10:54:27AM -0800, Palmer Dabbelt wrote: > >>> On Fri, 09 Mar 2018 10:36:44 PST (-0800)

Re: [PATCH v2 2/2] riscv/atomic: Strengthen implementations with fences

2018-03-09 Thread Daniel Lustig
On 3/9/2018 2:57 PM, Palmer Dabbelt wrote: > On Fri, 09 Mar 2018 13:30:08 PST (-0800), parri.and...@gmail.com wrote: >> On Fri, Mar 09, 2018 at 10:54:27AM -0800, Palmer Dabbelt wrote: >>> On Fri, 09 Mar 2018 10:36:44 PST (-0800), parri.and...@gmail.com wrote: >> >> [...] >> >>> >This proposal relie

Re: [PATCH v2 2/2] riscv/atomic: Strengthen implementations with fences

2018-03-09 Thread Palmer Dabbelt
On Fri, 09 Mar 2018 13:30:08 PST (-0800), parri.and...@gmail.com wrote: On Fri, Mar 09, 2018 at 10:54:27AM -0800, Palmer Dabbelt wrote: On Fri, 09 Mar 2018 10:36:44 PST (-0800), parri.and...@gmail.com wrote: [...] >This belongs to the "few style fixes" (in the specific, 80-chars lines) >men

Re: [PATCH v2 2/2] riscv/atomic: Strengthen implementations with fences

2018-03-09 Thread Andrea Parri
On Fri, Mar 09, 2018 at 10:54:27AM -0800, Palmer Dabbelt wrote: > On Fri, 09 Mar 2018 10:36:44 PST (-0800), parri.and...@gmail.com wrote: [...] > >This belongs to the "few style fixes" (in the specific, 80-chars lines) > >mentioned in the cover letter; I could not resist ;-), but I'll remove > >

Re: [PATCH v2 2/2] riscv/atomic: Strengthen implementations with fences

2018-03-09 Thread Palmer Dabbelt
On Fri, 09 Mar 2018 10:36:44 PST (-0800), parri.and...@gmail.com wrote: On Fri, Mar 09, 2018 at 09:56:21AM -0800, Palmer Dabbelt wrote: On Fri, 09 Mar 2018 04:13:40 PST (-0800), parri.and...@gmail.com wrote: >Atomics present the same issue with locking: release and acquire >variants need to be s

Re: [PATCH v2 2/2] riscv/atomic: Strengthen implementations with fences

2018-03-09 Thread Andrea Parri
On Fri, Mar 09, 2018 at 09:56:21AM -0800, Palmer Dabbelt wrote: > On Fri, 09 Mar 2018 04:13:40 PST (-0800), parri.and...@gmail.com wrote: > >Atomics present the same issue with locking: release and acquire > >variants need to be strengthened to meet the constraints defined > >by the Linux-kernel me

Re: [PATCH v2 2/2] riscv/atomic: Strengthen implementations with fences

2018-03-09 Thread Palmer Dabbelt
On Fri, 09 Mar 2018 04:13:40 PST (-0800), parri.and...@gmail.com wrote: Atomics present the same issue with locking: release and acquire variants need to be strengthened to meet the constraints defined by the Linux-kernel memory consistency model [1]. Atomics present a further issue: implementat

Re: [PATCH v2 2/2] riscv/atomic: Strengthen implementations with fences

2018-03-09 Thread Andrea Parri
On Fri, Mar 09, 2018 at 11:39:11AM -0500, Alan Stern wrote: > On Fri, 9 Mar 2018, Andrea Parri wrote: > > > Atomics present the same issue with locking: release and acquire > > variants need to be strengthened to meet the constraints defined > > by the Linux-kernel memory consistency model [1]. >

Re: [PATCH v2 2/2] riscv/atomic: Strengthen implementations with fences

2018-03-09 Thread Alan Stern
On Fri, 9 Mar 2018, Andrea Parri wrote: > Atomics present the same issue with locking: release and acquire > variants need to be strengthened to meet the constraints defined > by the Linux-kernel memory consistency model [1]. > > Atomics present a further issue: implementations of atomics such >

[PATCH v2 2/2] riscv/atomic: Strengthen implementations with fences

2018-03-09 Thread Andrea Parri
Atomics present the same issue with locking: release and acquire variants need to be strengthened to meet the constraints defined by the Linux-kernel memory consistency model [1]. Atomics present a further issue: implementations of atomics such as atomic_cmpxchg() and atomic_add_unless() rely on L