[PATCH 2/2] arm64:vdso: Remove ISB from gettimeofday.

2017-05-30 Thread Andrew Pinski
ISB is normally required before mrs CNTVCT if we want the mrs to completed after the loads. In this case it is not. As we are taking the difference and if that difference was going to be negative, we just use the last counter value instead. Signed-off-by: Andrew Pinski ---

[PATCH 2/2] arm64:vdso: Remove ISB from gettimeofday.

2017-05-30 Thread Andrew Pinski
ISB is normally required before mrs CNTVCT if we want the mrs to completed after the loads. In this case it is not. As we are taking the difference and if that difference was going to be negative, we just use the last counter value instead. Signed-off-by: Andrew Pinski ---

Re: [PATCH 2/2] arm64:vdso: Remove ISB from gettimeofday.

2017-05-06 Thread Jon Masters
Quick reply - didn't realize it could be speculatively read as described, but I should have. Makes sense now, thanks. -- Computer Architect | Sent from my 64-bit #ARM Powered phone > On May 6, 2017, at 13:38, Pinski, Andrew wrote: > > Sorry sending again as plain

Re: [PATCH 2/2] arm64:vdso: Remove ISB from gettimeofday.

2017-05-06 Thread Jon Masters
Quick reply - didn't realize it could be speculatively read as described, but I should have. Makes sense now, thanks. -- Computer Architect | Sent from my 64-bit #ARM Powered phone > On May 6, 2017, at 13:38, Pinski, Andrew wrote: > > Sorry sending again as plain text (I did not notice that

RE: [PATCH 2/2] arm64:vdso: Remove ISB from gettimeofday.

2017-05-06 Thread Pinski, Andrew
Sorry sending again as plain text (I did not notice that before). On 5/6/2017 9:29 AM, Jon Masters wrote: On 04/23/2017 07:47 PM, Andrew Pinski wrote: > ISB is normally required before mrs CNTVCT if we want the > mrs to completed after the loads. In this case it is not. > As we are taking the

RE: [PATCH 2/2] arm64:vdso: Remove ISB from gettimeofday.

2017-05-06 Thread Pinski, Andrew
Sorry sending again as plain text (I did not notice that before). On 5/6/2017 9:29 AM, Jon Masters wrote: On 04/23/2017 07:47 PM, Andrew Pinski wrote: > ISB is normally required before mrs CNTVCT if we want the > mrs to completed after the loads. In this case it is not. > As we are taking the

Re: [PATCH 2/2] arm64:vdso: Remove ISB from gettimeofday.

2017-05-06 Thread Jon Masters
On 04/23/2017 07:47 PM, Andrew Pinski wrote: > ISB is normally required before mrs CNTVCT if we want the > mrs to completed after the loads. In this case it is not. > As we are taking the difference and if that difference > was going to be negative, we just use the last counter value > instead. >

Re: [PATCH 2/2] arm64:vdso: Remove ISB from gettimeofday.

2017-05-06 Thread Jon Masters
On 04/23/2017 07:47 PM, Andrew Pinski wrote: > ISB is normally required before mrs CNTVCT if we want the > mrs to completed after the loads. In this case it is not. > As we are taking the difference and if that difference > was going to be negative, we just use the last counter value > instead. >

[PATCH 2/2] arm64:vdso: Remove ISB from gettimeofday.

2017-04-23 Thread Andrew Pinski
ISB is normally required before mrs CNTVCT if we want the mrs to completed after the loads. In this case it is not. As we are taking the difference and if that difference was going to be negative, we just use the last counter value instead. Signed-off-by: Andrew Pinski ---

[PATCH 2/2] arm64:vdso: Remove ISB from gettimeofday.

2017-04-23 Thread Andrew Pinski
ISB is normally required before mrs CNTVCT if we want the mrs to completed after the loads. In this case it is not. As we are taking the difference and if that difference was going to be negative, we just use the last counter value instead. Signed-off-by: Andrew Pinski ---