Re: [PATCH 2/2] arm64: preempt: Provide our own implementation of asm/preempt.h

2018-11-28 Thread Ard Biesheuvel
On Wed, 28 Nov 2018 at 17:41, Peter Zijlstra wrote: > > On Wed, Nov 28, 2018 at 04:35:42PM +0100, Ard Biesheuvel wrote: > > On Tue, 27 Nov 2018 at 20:44, Will Deacon wrote: > > > > > > The asm-generic/preempt.h implementation doesn't make use of the > > > PREEMPT_NEED_RESCHED flag, since this

Re: [PATCH 2/2] arm64: preempt: Provide our own implementation of asm/preempt.h

2018-11-28 Thread Ard Biesheuvel
On Wed, 28 Nov 2018 at 17:41, Peter Zijlstra wrote: > > On Wed, Nov 28, 2018 at 04:35:42PM +0100, Ard Biesheuvel wrote: > > On Tue, 27 Nov 2018 at 20:44, Will Deacon wrote: > > > > > > The asm-generic/preempt.h implementation doesn't make use of the > > > PREEMPT_NEED_RESCHED flag, since this

Re: [PATCH 2/2] arm64: preempt: Provide our own implementation of asm/preempt.h

2018-11-28 Thread Peter Zijlstra
On Wed, Nov 28, 2018 at 04:35:42PM +0100, Ard Biesheuvel wrote: > On Tue, 27 Nov 2018 at 20:44, Will Deacon wrote: > > > > The asm-generic/preempt.h implementation doesn't make use of the > > PREEMPT_NEED_RESCHED flag, since this can interact badly with load/store > > architectures which rely on

Re: [PATCH 2/2] arm64: preempt: Provide our own implementation of asm/preempt.h

2018-11-28 Thread Peter Zijlstra
On Wed, Nov 28, 2018 at 04:35:42PM +0100, Ard Biesheuvel wrote: > On Tue, 27 Nov 2018 at 20:44, Will Deacon wrote: > > > > The asm-generic/preempt.h implementation doesn't make use of the > > PREEMPT_NEED_RESCHED flag, since this can interact badly with load/store > > architectures which rely on

Re: [PATCH 2/2] arm64: preempt: Provide our own implementation of asm/preempt.h

2018-11-28 Thread Ard Biesheuvel
On Tue, 27 Nov 2018 at 20:44, Will Deacon wrote: > > The asm-generic/preempt.h implementation doesn't make use of the > PREEMPT_NEED_RESCHED flag, since this can interact badly with load/store > architectures which rely on the preempt_count word being unchanged across > an interrupt. > > However,

Re: [PATCH 2/2] arm64: preempt: Provide our own implementation of asm/preempt.h

2018-11-28 Thread Ard Biesheuvel
On Tue, 27 Nov 2018 at 20:44, Will Deacon wrote: > > The asm-generic/preempt.h implementation doesn't make use of the > PREEMPT_NEED_RESCHED flag, since this can interact badly with load/store > architectures which rely on the preempt_count word being unchanged across > an interrupt. > > However,