Re: [RFC][PATCH] time: Add warning about imminent deprecation of CONFIG_GENERIC_TIME_VSYSCALL_OLD

2017-05-26 Thread John Stultz
On Thu, May 25, 2017 at 5:03 AM, Paul Mackerras wrote: > On Mon, May 22, 2017 at 12:06:04PM -0700, John Stultz wrote: >> >> Basically long ago, timekeeping was handled (roughly) like: >> >> clock_gettime(): >> now = tk->clock->read() >> offset_ns = ((now -

Re: [RFC][PATCH] time: Add warning about imminent deprecation of CONFIG_GENERIC_TIME_VSYSCALL_OLD

2017-05-26 Thread John Stultz
On Thu, May 25, 2017 at 5:03 AM, Paul Mackerras wrote: > On Mon, May 22, 2017 at 12:06:04PM -0700, John Stultz wrote: >> >> Basically long ago, timekeeping was handled (roughly) like: >> >> clock_gettime(): >> now = tk->clock->read() >> offset_ns = ((now - tk->cycle_last) *

Re: [RFC][PATCH] time: Add warning about imminent deprecation of CONFIG_GENERIC_TIME_VSYSCALL_OLD

2017-05-25 Thread Paul Mackerras
On Mon, May 22, 2017 at 12:06:04PM -0700, John Stultz wrote: > > Basically long ago, timekeeping was handled (roughly) like: > > clock_gettime(): > now = tk->clock->read() > offset_ns = ((now - tk->cycle_last) * tk->clock->mult) >> > tk->clock->shift; > return

Re: [RFC][PATCH] time: Add warning about imminent deprecation of CONFIG_GENERIC_TIME_VSYSCALL_OLD

2017-05-25 Thread Paul Mackerras
On Mon, May 22, 2017 at 12:06:04PM -0700, John Stultz wrote: > > Basically long ago, timekeeping was handled (roughly) like: > > clock_gettime(): > now = tk->clock->read() > offset_ns = ((now - tk->cycle_last) * tk->clock->mult) >> > tk->clock->shift; > return

Re: [RFC][PATCH] time: Add warning about imminent deprecation of CONFIG_GENERIC_TIME_VSYSCALL_OLD

2017-05-24 Thread Michael Ellerman
John Stultz writes: ... > So, long ago I talked w/ Paul Mackerras about the ppc vdso code, as > ppc has some other legacy "userspace time" code that has to be > maintained as well (I believe there's not code page, just data page > that userspace pulls directly from). So

Re: [RFC][PATCH] time: Add warning about imminent deprecation of CONFIG_GENERIC_TIME_VSYSCALL_OLD

2017-05-24 Thread Michael Ellerman
John Stultz writes: ... > So, long ago I talked w/ Paul Mackerras about the ppc vdso code, as > ppc has some other legacy "userspace time" code that has to be > maintained as well (I believe there's not code page, just data page > that userspace pulls directly from). So for that case, we have the

Re: [RFC][PATCH] time: Add warning about imminent deprecation of CONFIG_GENERIC_TIME_VSYSCALL_OLD

2017-05-22 Thread Benjamin Herrenschmidt
On Mon, 2017-05-22 at 12:06 -0700, John Stultz wrote: > So, long ago I talked w/ Paul Mackerras about the ppc vdso code, as > ppc has some other legacy "userspace time" code that has to be > maintained as well (I believe there's not code page, just data page > that userspace pulls directly from).

Re: [RFC][PATCH] time: Add warning about imminent deprecation of CONFIG_GENERIC_TIME_VSYSCALL_OLD

2017-05-22 Thread Benjamin Herrenschmidt
On Mon, 2017-05-22 at 12:06 -0700, John Stultz wrote: > So, long ago I talked w/ Paul Mackerras about the ppc vdso code, as > ppc has some other legacy "userspace time" code that has to be > maintained as well (I believe there's not code page, just data page > that userspace pulls directly from).

Re: [RFC][PATCH] time: Add warning about imminent deprecation of CONFIG_GENERIC_TIME_VSYSCALL_OLD

2017-05-22 Thread John Stultz
On Sun, May 21, 2017 at 5:58 PM, Michael Ellerman wrote: > John Stultz writes: > >> CONFIG_GENERIC_TIME_VSYSCALL_OLD was introduced five years ago >> to allow a transition from the old vsyscall implementations to >> the new method (which simplified

Re: [RFC][PATCH] time: Add warning about imminent deprecation of CONFIG_GENERIC_TIME_VSYSCALL_OLD

2017-05-22 Thread John Stultz
On Sun, May 21, 2017 at 5:58 PM, Michael Ellerman wrote: > John Stultz writes: > >> CONFIG_GENERIC_TIME_VSYSCALL_OLD was introduced five years ago >> to allow a transition from the old vsyscall implementations to >> the new method (which simplified internal accounting and made >> timekeeping

Re: [RFC][PATCH] time: Add warning about imminent deprecation of CONFIG_GENERIC_TIME_VSYSCALL_OLD

2017-05-21 Thread Michael Ellerman
John Stultz writes: > CONFIG_GENERIC_TIME_VSYSCALL_OLD was introduced five years ago > to allow a transition from the old vsyscall implementations to > the new method (which simplified internal accounting and made > timekeeping more precise). I'm sure it's completely

Re: [RFC][PATCH] time: Add warning about imminent deprecation of CONFIG_GENERIC_TIME_VSYSCALL_OLD

2017-05-21 Thread Michael Ellerman
John Stultz writes: > CONFIG_GENERIC_TIME_VSYSCALL_OLD was introduced five years ago > to allow a transition from the old vsyscall implementations to > the new method (which simplified internal accounting and made > timekeeping more precise). I'm sure it's completely obvious to everyone except

[RFC][PATCH] time: Add warning about imminent deprecation of CONFIG_GENERIC_TIME_VSYSCALL_OLD

2017-05-12 Thread John Stultz
CONFIG_GENERIC_TIME_VSYSCALL_OLD was introduced five years ago to allow a transition from the old vsyscall implementations to the new method (which simplified internal accounting and made timekeeping more precise). However, PPC and IA64 have yet to make the transition, despite in some cases me

[RFC][PATCH] time: Add warning about imminent deprecation of CONFIG_GENERIC_TIME_VSYSCALL_OLD

2017-05-12 Thread John Stultz
CONFIG_GENERIC_TIME_VSYSCALL_OLD was introduced five years ago to allow a transition from the old vsyscall implementations to the new method (which simplified internal accounting and made timekeeping more precise). However, PPC and IA64 have yet to make the transition, despite in some cases me