In preparation for making the clockevents core NTP correction aware,
all clockevent device drivers must set ->min_delta_ticks and
->max_delta_ticks rather than ->min_delta_ns and ->max_delta_ns: a
clockevent device's rate is going to change dynamically and thus, the
ratio of ns to ticks ceases to stay invariant.
Make the sh_cmt clockevent driver initialize these fields properly.
This patch alone doesn't introduce any change in functionality as the
clockevents core still looks exclusively at the (untouched) ->min_delta_ns
and ->max_delta_ns. As soon as this has changed, a followup patch will
purge the initialization of ->min_delta_ns and ->max_delta_ns from this
driver.
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
In preparation for making the clockevents core NTP correction aware,
all clockevent device drivers must set ->min_delta_ticks and
->max_delta_ticks rather than ->min_delta_ns and ->max_delta_ns: a
clockevent device's rate is going to change dynamically and thus, the
ratio of ns to ticks ceases to stay invariant.
Make the numachip clockevent driver initialize these fields properly.
This patch alone doesn't introduce any change in functionality as the
clockevents core still looks exclusively at the (untouched) ->min_delta_ns
and ->max_delta_ns. As soon as this has changed, a followup patch will
purge the initialization of ->min_delta_ns and ->max_delta_ns from this
driver.
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
In preparation for making the clockevents core NTP correction aware,
all clockevent device drivers must set ->min_delta_ticks and
->max_delta_ticks rather than ->min_delta_ns and ->max_delta_ns: a
clockevent device's rate is going to change dynamically and thus, the
ratio of ns to ticks ceases to stay invariant.
Make the metag_generic clockevent driver initialize these fields properly.
This patch alone doesn't introduce any change in functionality as the
clockevents core still looks exclusively at the (untouched) ->min_delta_ns
and ->max_delta_ns. As soon as this has changed, a followup patch will
purge the initialization of ->min_delta_ns and ->max_delta_ns from this
driver.
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: James Hogan <james.hogan@imgtec.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
In preparation for making the clockevents core NTP correction aware,
all clockevent device drivers must set ->min_delta_ticks and
->max_delta_ticks rather than ->min_delta_ns and ->max_delta_ns: a
clockevent device's rate is going to change dynamically and thus, the
ratio of ns to ticks ceases to stay invariant.
Make the dw_apb clockevent driver initialize these fields properly.
This patch alone doesn't introduce any change in functionality as the
clockevents core still looks exclusively at the (untouched) ->min_delta_ns
and ->max_delta_ns. As soon as this has changed, a followup patch will
purge the initialization of ->min_delta_ns and ->max_delta_ns from this
driver.
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
In preparation for making the clockevents core NTP correction aware,
all clockevent device drivers must set ->min_delta_ticks and
->max_delta_ticks rather than ->min_delta_ns and ->max_delta_ns: a
clockevent device's rate is going to change dynamically and thus, the
ratio of ns to ticks ceases to stay invariant.
Make the hexagon arch's clockevent driver initialize these fields
properly.
This patch alone doesn't introduce any change in functionality as the
clockevents core still looks exclusively at the (untouched) ->min_delta_ns
and ->max_delta_ns. As soon as this has changed, a followup patch will
purge the initialization of ->min_delta_ns and ->max_delta_ns from this
driver.
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: linux-hexagon@vger.kernel.org
Acked-by: Richard Kuo <rkuo@codeaurora.org>
Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
In preparation for making the clockevents core NTP correction aware,
all clockevent device drivers must set ->min_delta_ticks and
->max_delta_ticks rather than ->min_delta_ns and ->max_delta_ns: a
clockevent device's rate is going to change dynamically and thus, the
ratio of ns to ticks ceases to stay invariant.
Make the x86 arch's lguest clockevent driver initialize these fields
properly.
This patch alone doesn't introduce any change in functionality as the
clockevents core still looks exclusively at the (untouched) ->min_delta_ns
and ->max_delta_ns. As soon as this has changed, a followup patch will
purge the initialization of ->min_delta_ns and ->max_delta_ns from this
driver.
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
Cc: Paul Bolle <pebolle@tiscali.nl>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Juergen Gross <jgross@suse.com>
Cc: "Luis R. Rodriguez" <mcgrof@kernel.org>
Cc: lguest@lists.ozlabs.org
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
In preparation for making the clockevents core NTP correction aware,
all clockevent device drivers must set ->min_delta_ticks and
->max_delta_ticks rather than ->min_delta_ns and ->max_delta_ns: a
clockevent device's rate is going to change dynamically and thus, the
ratio of ns to ticks ceases to stay invariant.
Make the sparc arch's clockevent drivers initialize these fields properly.
This patch alone doesn't introduce any change in functionality as the
clockevents core still looks exclusively at the (untouched) ->min_delta_ns
and ->max_delta_ns. As soon as this has changed, a followup patch will
purge the initialization of ->min_delta_ns and ->max_delta_ns from these
drivers.
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: sparclinux@vger.kernel.org
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
In preparation for making the clockevents core NTP correction aware,
all clockevent device drivers must set ->min_delta_ticks and
->max_delta_ticks rather than ->min_delta_ns and ->max_delta_ns: a
clockevent device's rate is going to change dynamically and thus, the
ratio of ns to ticks ceases to stay invariant.
Make the powerpc arch's clockevent driver initialize these fields properly.
This patch alone doesn't introduce any change in functionality as the
clockevents core still looks exclusively at the (untouched) ->min_delta_ns
and ->max_delta_ns. As soon as this has changed, a followup patch will
purge the initialization of ->min_delta_ns and ->max_delta_ns from this
driver.
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Oliver O'Halloran <oohall@gmail.com>
Cc: linuxppc-dev@lists.ozlabs.org
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
In preparation for making the clockevents core NTP correction aware,
all clockevent device drivers must set ->min_delta_ticks and
->max_delta_ticks rather than ->min_delta_ns and ->max_delta_ns: a
clockevent device's rate is going to change dynamically and thus, the
ratio of ns to ticks ceases to stay invariant.
Make the m68k arch's coldfire clockevent driver initialize these fields
properly.
This patch alone doesn't introduce any change in functionality as the
clockevents core still looks exclusively at the (untouched) ->min_delta_ns
and ->max_delta_ns. As soon as this has changed, a followup patch will
purge the initialization of ->min_delta_ns and ->max_delta_ns from this
driver.
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: Greg Ungerer <gerg@linux-m68k.org>
CC: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: linux-m68k@lists.linux-m68k.org
Acked-by: Greg Ungerer <gerg@linux-m68k.org>
Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
In preparation for making the clockevents core NTP correction aware,
all clockevent device drivers must set ->min_delta_ticks and
->max_delta_ticks rather than ->min_delta_ns and ->max_delta_ns: a
clockevent device's rate is going to change dynamically and thus, the
ratio of ns to ticks ceases to stay invariant.
Make the x86 arch's xen clockevent driver initialize these fields properly.
This patch alone doesn't introduce any change in functionality as the
clockevents core still looks exclusively at the (untouched) ->min_delta_ns
and ->max_delta_ns. As soon as this has changed, a followup patch will
purge the initialization of ->min_delta_ns and ->max_delta_ns from this
driver.
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: x86@kernel.org
Cc: xen-devel@lists.xenproject.org
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Pull timekeeping changes from John Stultz:
Main changes are the initial steps of Nicoli's work to make the clockevent
timers be corrected for NTP adjustments. Then a few smaller fixes that
I've queued, and adding Stephen Boyd to the maintainers list for
timekeeping.
On systems with a large number of CPUs, running sysrq-<q> can cause
watchdog timeouts. There are two slow sections of code in the sysrq-<q>
path in timer_list.c.
1. print_active_timers() - This function is called by print_cpu() and
contains a slow goto loop. On a machine with hundreds of CPUs, this
loop took approximately 100ms for the first CPU in a NUMA node.
(Subsequent CPUs in the same node ran much quicker.) The total time
to print all of the CPUs is ultimately long enough to trigger the
soft lockup watchdog.
2. print_tickdevice() - This function outputs a large amount of textual
information. This function also took approximately 100ms per CPU.
Since sysrq-<q> is not a performance critical path, there should be no
harm in touching the nmi watchdog in both slow sections above. Touching
it in just one location was insufficient on systems with hundreds of
CPUs as occasional timeouts were still observed during testing.
This issue was observed on an Oracle T7 machine with 128 CPUs, but I
anticipate it may affect other systems with similarly large numbers of
CPUs.
Signed-off-by: Tom Hromatka <tom.hromatka@oracle.com>
Reviewed-by: Rob Gardner <rob.gardner@oracle.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
The scheduler clock framework may not use the correct timeout for the clock
wrap. This happens when a new clock driver calls sched_clock_register()
after the kernel called sched_clock_postinit(). In this case the clock wrap
timeout is too long thus sched_clock_poll() is called too late and the clock
already wrapped.
On my ARM system the scheduler was no longer scheduling any other task than
the idle task because the sched_clock() wrapped.
Signed-off-by: David Engraf <david.engraf@sysgo.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
A clockevent device's rate should be configured before or at registration
and changed afterwards through clockevents_update_freq() only.
For the configuration at registration, we already have
clockevents_config_and_register().
Right now, there are no clockevents_config() users outside of the
clockevents core.
To mitigiate the risk of drivers errorneously reconfiguring their rates
through clockevents_config() *after* device registration, make
clockevents_config() static.
Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
With the upcoming NTP correction related rate adjustments to be implemented
in the clockevents core, the latter needs to get informed about every rate
change of a clockevent device made after its registration.
Currently, h8300_timer8 violates this requirement in that it registers its
clockevent device with the correct rate, but resets its ->mult and ->rate
values in timer8_clock_event_start(), called from its ->set_state_oneshot()
function.
It seems like
commit 4633f4cac8 ("clocksource/drivers/h8300: Cleanup startup and
remove module code."),
which introduced the rate initialization at registration, missed to remove
the manual setting of ->mult and ->shift from timer8_clock_event_start().
Purge the setting of ->mult, ->shift, ->min_delta_ns and ->max_delta_ns
from timer8_clock_event_start().
Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
With the upcoming NTP correction related rate adjustments to be implemented
in the clockevents core, the latter needs to get informed about every rate
change of a clockevent device made after its registration.
Currently, em_sti violates this requirement in that it registers its
clockevent device with a dummy rate and sets its final rate through
clockevents_config() called from its ->set_state_oneshot().
This patch moves the setting of the clockevent device's rate to its
registration.
I checked all current em_sti users in arch/arm/mach-shmobile and right now,
none of them changes any rate in any clock tree relevant to em_sti after
their respective time_init(). Since all em_sti instances are created after
time_init(), none of them should ever observe any clock rate changes.
- Determine the ->rate value in em_sti_probe() at device probing rather
than at first usage.
- Set the clockevent device's rate at its registration.
- Although not strictly necessary for the upcoming clockevent core changes,
set the clocksource's rate at its registration for consistency.
Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Currently, the em_sti driver prepares and enables the needed clock in
em_sti_enable(), potentially called through its clockevent device's
->set_state_oneshot().
However, the clk_prepare() step may sleep whereas tick_program_event() and
thus, ->set_state_oneshot(), can be called in atomic context.
Split the clk_prepare_enable() in em_sti_enable() into two steps:
- prepare the clock at device probing via clk_prepare()
- and enable it in em_sti_enable() via clk_enable().
Slightly reorder resource initialization in em_sti_probe() in order to
facilitate error handling in later patches.
Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
With the upcoming NTP correction related rate adjustments to be implemented
in the clockevents core, the latter needs to get informed about every rate
change of a clockevent device made after its registration.
Currently, sh_tmu violates this requirement in that it registers its
clockevent device with a dummy rate and sets its final rate through
clockevents_config() called from its ->set_state_oneshot() and
->set_state_periodic() functions respectively.
This patch moves the setting of the clockevent device's rate to its
registration.
Note that there has been some back and forth regarding this question with
respect to the clocksource also provided by this driver:
commit 66f49121ff ("clocksource: sh_tmu: compute mult and shift before
registration")
moves the rate determination from the clocksource's ->enable() function to
before its registration. OTOH, the later
commit 0aeac458d9 ("clocksource: sh_tmu: __clocksource_updatefreq_hz()
update")
basically reverts this, saying
"Without this patch the old code uses clocksource_register() together
with a hack that assumes a never changing clock rate."
However, I checked all current sh_tmu users in arch/sh as well as in
arch/arm/mach-shmobile carefully and right now, none of them changes any
rate in any clock tree relevant to sh_tmu after their respective
time_init(). Since all sh_tmu instances are created after time_init(), none
of them should ever observe any clock rate changes.
What's more, both, a clocksource as well as a clockevent device, can
immediately get selected for use at their registration and thus, enabled
at this point already. So it's probably safer to assume a "never changing
clock rate" here.
- Move the struct sh_tmu_channel's ->rate member to struct sh_tmu_device:
it's a property of the underlying clock which is in turn specific to
the sh_tmu_device.
- Determine the ->rate value in sh_tmu_setup() at device probing rather
than at first usage.
- Set the clockevent device's rate at its registration.
- Although not strictly necessary for the upcoming clockevent core changes,
set the clocksource's rate at its registration for consistency.
Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
With the upcoming NTP correction related rate adjustments to be implemented
in the clockevents core, the latter needs to get informed about every rate
change of a clockevent device made after its registration.
Currently, sh_cmt violates this requirement in that it registers its
clockevent device with a dummy rate and sets its final ->mult and ->shift
values from its ->set_state_oneshot() and ->set_state_periodic() functions
respectively.
This patch moves the setting of the clockevent device's ->mult and ->shift
values to before its registration.
Note that there has been some back and forth regarding this question with
respect to the clocksource also provided by this driver:
commit f4d7c3565c ("clocksource: sh_cmt: compute mult and shift before
registration")
moves the rate determination from the clocksource's ->enable() function to
before its registration. OTOH, the later
commit 3593f5fe40 ("clocksource: sh_cmt: __clocksource_updatefreq_hz()
update")
basically reverts this, saying
"Without this patch the old code uses clocksource_register() together
with a hack that assumes a never changing clock rate."
However, I checked all current sh_cmt users in arch/sh as well as in
arch/arm/mach-shmobile carefully and right now, none of them changes any
rate in any clock tree relevant to sh_cmt after their respective
time_init(). Since all sh_cmt instances are created after time_init(), none
of them should ever observe any clock rate changes.
What's more, both, a clocksource as well as a clockevent device, can
immediately get selected for use at their registration and thus, enabled
at this point already. So it's probably safer to assume a "never changing
clock rate" here.
- Move the struct sh_cmt_channel's ->rate member to struct sh_cmt_device:
it's a property of the underlying clock which is in turn specific to
the sh_cmt_device.
- Determine the ->rate value in sh_cmt_setup() at device probing rather
than at first usage.
- Set the clockevent device's ->mult and ->shift values right before its
registration.
- Although not strictly necessary for the upcoming clockevent core changes,
set the clocksource's rate at its registration for consistency.
Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
This BUG_ON() triggered for me once at shutdown, and I don't see a
reason for the check. The code correctly checks whether the swap slot
cache is usable or not, so an uninitialized swap slot cache is not
actually problematic afaik.
I've temporarily just switched the BUG_ON() to a WARN_ON_ONCE(), since
I'm not sure why that seemingly pointless check was there. I suspect
the real fix is to just remove it entirely, but for now we'll warn about
it but not bring the machine down.
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull more powerpc fixes from Michael Ellerman:
"A couple of minor powerpc fixes for 4.11:
- wire up statx() syscall
- don't print a warning on memory hotplug when HPT resizing isn't
available
Thanks to: David Gibson, Chandan Rajendra"
* tag 'powerpc-4.11-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
powerpc/pseries: Don't give a warning when HPT resizing isn't available
powerpc: Wire up statx() syscall
Pull parisc fixes from Helge Deller:
- Mikulas Patocka added support for R_PARISC_SECREL32 relocations in
modules with CONFIG_MODVERSIONS.
- Dave Anglin optimized the cache flushing for vmap ranges.
- Arvind Yadav provided a fix for a potential NULL pointer dereference
in the parisc perf code (and some code cleanups).
- I wired up the new statx system call, fixed some compiler warnings
with the access_ok() macro and fixed shutdown code to really halt a
system at shutdown instead of crashing & rebooting.
* 'parisc-4.11-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
parisc: Fix system shutdown halt
parisc: perf: Fix potential NULL pointer dereference
parisc: Avoid compiler warnings with access_ok()
parisc: Wire up statx system call
parisc: Optimize flush_kernel_vmap_range and invalidate_kernel_vmap_range
parisc: support R_PARISC_SECREL32 relocation in modules
Nicolai Stange
Nicholas Mc Guire
Thomas Gleixner
Tom Hromatka
David Engraf
John Stultz
Linus Torvalds