Re: Memory synchronization vs. interrupt handlers

2013-09-02 Thread Catalin Marinas
On 26 August 2013 16:49, Alan Stern wrote: > Here's a question that doesn't seem to be answered in > Documentation/memory-barriers.txt. Are memory accesses within an > interrupt handler synchronized with respect to interrupts? > > In more detail, suppose we have an interrupt handler that uses a m

Re: Memory synchronization vs. interrupt handlers

2013-08-29 Thread H. Peter Anvin
On 08/29/2013 04:51 PM, Paul E. McKenney wrote: > On Wed, Aug 28, 2013 at 01:28:08PM -0700, H. Peter Anvin wrote: >> On 08/28/2013 12:16 PM, Alan Stern wrote: >>> Russell, Peter, and Ingo: >>> >>> Can you folks enlighten us regarding this issue for some common >>> architectures? >> >> On x86, IRET

Re: Memory synchronization vs. interrupt handlers

2013-08-29 Thread Benjamin Herrenschmidt
On Thu, 2013-08-29 at 16:51 -0700, Paul E. McKenney wrote: > On Wed, Aug 28, 2013 at 01:28:08PM -0700, H. Peter Anvin wrote: > > On 08/28/2013 12:16 PM, Alan Stern wrote: > > > Russell, Peter, and Ingo: > > > > > > Can you folks enlighten us regarding this issue for some common > > > architecture

Re: Memory synchronization vs. interrupt handlers

2013-08-29 Thread Paul E. McKenney
On Wed, Aug 28, 2013 at 01:28:08PM -0700, H. Peter Anvin wrote: > On 08/28/2013 12:16 PM, Alan Stern wrote: > > Russell, Peter, and Ingo: > > > > Can you folks enlighten us regarding this issue for some common > > architectures? > > On x86, IRET is a serializing instruction; it guarantees hard >

Re: Memory synchronization vs. interrupt handlers

2013-08-29 Thread Alan Stern
On Wed, 28 Aug 2013, H. Peter Anvin wrote: > On 08/28/2013 12:16 PM, Alan Stern wrote: > > Russell, Peter, and Ingo: > > > > Can you folks enlighten us regarding this issue for some common > > architectures? > > > > On x86, IRET is a serializing instruction; it guarantees hard > serialization

Re: Memory synchronization vs. interrupt handlers

2013-08-28 Thread H. Peter Anvin
On 08/28/2013 12:16 PM, Alan Stern wrote: > Russell, Peter, and Ingo: > > Can you folks enlighten us regarding this issue for some common > architectures? > On x86, IRET is a serializing instruction; it guarantees hard serialization of absolutely everything. I would expect architectures that h

Re: Memory synchronization vs. interrupt handlers

2013-08-28 Thread Alan Stern
Russell, Peter, and Ingo: Can you folks enlighten us regarding this issue for some common architectures? On Tue, 27 Aug 2013, Paul E. McKenney wrote: > On Mon, Aug 26, 2013 at 11:49:15AM -0400, Alan Stern wrote: > > David and Paul: > > > > Here's a question that doesn't seem to be answered in

Re: Memory synchronization vs. interrupt handlers

2013-08-27 Thread Paul E. McKenney
On Mon, Aug 26, 2013 at 11:49:15AM -0400, Alan Stern wrote: > David and Paul: > > Here's a question that doesn't seem to be answered in > Documentation/memory-barriers.txt. Are memory accesses within an > interrupt handler synchronized with respect to interrupts? > > In more detail, suppose we