Re: [RFC] arm64: Implement WFE based spin wait for MCS spinlocks

2016-04-20 Thread Jason Low
On Wed, 2016-04-20 at 12:30 +0200, Peter Zijlstra wrote: > On Thu, Apr 14, 2016 at 12:13:38AM -0700, Jason Low wrote: > > Use WFE to avoid most spinning with MCS spinlocks. This is implemented > > with the new cmpwait() mechanism for comparing and waiting for the MCS > > locked value to change usin

Re: [RFC] arm64: Implement WFE based spin wait for MCS spinlocks

2016-04-20 Thread Peter Zijlstra
On Thu, Apr 14, 2016 at 12:13:38AM -0700, Jason Low wrote: > Use WFE to avoid most spinning with MCS spinlocks. This is implemented > with the new cmpwait() mechanism for comparing and waiting for the MCS > locked value to change using LDXR + WFE. > > Signed-off-by: Jason Low > --- > arch/arm64/

[RFC] arm64: Implement WFE based spin wait for MCS spinlocks

2016-04-14 Thread Jason Low
Use WFE to avoid most spinning with MCS spinlocks. This is implemented with the new cmpwait() mechanism for comparing and waiting for the MCS locked value to change using LDXR + WFE. Signed-off-by: Jason Low --- arch/arm64/include/asm/mcs_spinlock.h | 21 + 1 file changed, 21