commit 6889125b8b upstream.
powernowk8_target() runs off a per-cpu work item and if the
cpufreq_policy->cpu is different from the current one, it migrates the
kworker to the target CPU by manipulating current->cpus_allowed. The
function migrates the kworker back to the original CPU but this is
still broken. Workqueue concurrency management requires the kworkers
to stay on the same CPU and powernowk8_target() ends up triggerring
BUG_ON(rq != this_rq()) in try_to_wake_up_local() if it contends on
fidvid_mutex and sleeps.
It is unclear why this bug is being reported now. Duncan says it
appeared to be a regression of 3.6-rc1 and couldn't reproduce it on
3.5. Bisection seemed to point to 63d95a91 "workqueue: use @pool
instead of @gcwq or @cpu where applicable" which is an non-functional
change. Given that the reproduce case sometimes took upto days to
trigger, it's easy to be misled while bisecting. Maybe something made
contention on fidvid_mutex more likely? I don't know.
This patch fixes the bug by using work_on_cpu() instead if @pol->cpu
isn't the same as the current one. The code assumes that
cpufreq_policy->cpu is kept online by the caller, which Rafael tells
me is the case.
stable: ed48ece27c ("workqueue: reimplement work_on_cpu() using
system_wq") should be applied before this; otherwise, the
behavior could be horrible.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Duncan <1i5t5.duncan@cox.net>
Tested-by: Duncan <1i5t5.duncan@cox.net>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Andreas Herrmann <andreas.herrmann3@amd.com>
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=47301
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Allow speed to drop to flooor frequency but not below, don't pin
to speed at last boost.
Change-Id: I0147c2b7a2e61ba16820605af6baaf09570be787
Signed-off-by: Todd Poynor <toddpoynor@google.com>
Allow speed drop after min_sample_time elapses from last time
the current speed was last re-validated as appropriate for
current load / input boost.
Allow speed bump after min_sample_time (or above_hispeed_delay)
elapses from the time the current speed was originally set.
Change-Id: Ic25687a7a53d25e6544c30c47d7ab6f27a47bee8
Signed-off-by: Todd Poynor <toddpoynor@google.com>
For systems that set a common speed for all CPUs, checking current
speed here could bypass the intermediate hispeed bump decision for
this CPU when another CPU was already at hispeed. This could
result in an overly high setting (for all CPUs) in situations
where all CPUs were about to drop to load levels that map to
hispeed or below.
Change-Id: I186f23dcfc5e2b6336cab8b0327f0c8a9a4482bc
Signed-off-by: Todd Poynor <toddpoynor@google.com>
Apply min_sample_time to the last time the current target speed
was originally requested or re-validated as appropriate for the
current load, not to the time since the current speed was
originally set. Avoids periodic dips in speed during bursty
loads.
Change-Id: I250bda657985de60373f9897cc41f480664d51a1
Signed-off-by: Todd Poynor <toddpoynor@google.com>
If load is above go_hispeed_load, always go to at least hispeed_freq,
even when reducing speed from a higher speed, not just when jumping
up from minimum speed. Avoids running at a lower than intended
speed after a burst of even higher load.
Change-Id: I5b9d2a15ba25ce609b21bac7c724265cf6838dee
Signed-off-by: Todd Poynor <toddpoynor@google.com>
Evaluate spikes in load (below go_hispeed_load) against the maximum
speed supported by the device, not the current speed (which tends to
make it too difficult to raise speed to intermediate levels until
very busy).
Change-Id: Ib937006abf8bedb60891a739acd733e89b732ae0
Signed-off-by: Todd Poynor <toddpoynor@google.com>
commit a8eb28480e upstream.
The driver uses the pstate number from the status register as index in
its table of ACPI pstates (powernow_table). This is wrong as this is
not a 1-to-1 mapping.
For example we can have _PSS information to just utilize Pstate 0 and
Pstate 4, ie.
powernow-k8: Core Performance Boosting: on.
powernow-k8: 0 : pstate 0 (2200 MHz)
powernow-k8: 1 : pstate 4 (1400 MHz)
In this example the driver's powernow_table has just 2 entries. Using
the pstate number (4) as index into this table is just plain wrong.
Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
Signed-off-by: Dave Jones <davej@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 201bf0f129 upstream.
Due to CPB we can't directly map SW Pstates to Pstate MSRs. Get rid of
the paranoia check. (assuming that the ACPI Pstate information is
correct.)
Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com>
Signed-off-by: Dave Jones <davej@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Add attribute hispeed_freq, which defaults to max.
* Rename go_maxspeed_load to go_hispeed_load.
* If hit go_hispeed_load and at min speed, go to hispeed_freq;
if hit go_hispeed_load and already above min speed go to max
speed.
Change-Id: I1050dec5f013fc1177387352ba787a7e1c68703e
Signed-off-by: Todd Poynor <toddpoynor@google.com>
Calculate intermediate speed by applyng CPU load to current speed, not
max speed.
Change-Id: Idecf598b9a203b07c989c5d9e9c6efc67a1afc2e
Signed-off-by: Todd Poynor <toddpoynor@google.com>
Lower the default time at which a higher speed is allowed to run
before lowering based on lower CPU load from 80ms to 20ms. Most
Android devices should trade power for performance here,
although tablets and non-battery-powered devices may want to
override this default.
Change-Id: I1a4f7faeca12793c51d5b92db30a63cca8d4f1be
Signed-off-by: Todd Poynor <toddpoynor@google.com>
Modify default timer from 30ms to 10ms, sampling 2 jiffies after
idle exit on ARM as in Honeycomb.
Modify default go_maxspeed_load from 85% loaded to 95% loaded, for
use in phones where power savings is more important (tablets may be
best served overriding this).
Change-Id: I3361a6279979bfae1df5262666a2e30ea7a44328
Signed-off-by: Todd Poynor <toddpoynor@google.com>
The following dump was seen sometimes while resuming,
the only division by zero on this function can happen after
delta_time is reassigned, since at the start of the
function, there is jump that protects against values
less than 1000.
After that, If delta_time and delta_idle == 0,
we will hit a div 0
Division by zero in kernel.
Backtrace:
[<c0057184>] (dump_backtrace+0x0/0x110) from [<c05d5ecc>] (dump_stack+0x18/0x1c)
r6:010f3000 r5:c113dfb0 r4:c004afb0 r3:c6ff0000
[<c05d5eb4>] (dump_stack+0x0/0x1c) from [<c00572cc>] (__div0+0x1c/0x20)
[<c00572b0>] (__div0+0x0/0x20) from [<c02195d4>] (Ldiv0+0x8/0x10)
[<c03dfd64>] (cpufreq_interactive_timer+0x0/0x2c0) from [<c00a7efc>] (run_timer_softirq+0x154/0x260)
[<c00a7da8>] (run_timer_softirq+0x0/0x260) from [<c00a0c8c>] (__do_softirq+0xc8/0x194)
[<c00a0bc4>] (__do_softirq+0x0/0x194) from [<c00a1008>] (irq_exit+0xb4/0xb8)
[<c00a0f54>] (irq_exit+0x0/0xb8) from [<c00584b4>] (ipi_timer+0x44/0x48)
r4:c004a040 r3:00000001
[<c0058470>] (ipi_timer+0x0/0x48) from [<c004c3e4>] (do_local_timer+0x68/0x84)
r5:c004ae2c r4:c07991e8
[<c004c37c>] (do_local_timer+0x0/0x84) from [<c0052948>] (__irq_svc+0x48/0xe0)
Change-Id: I639882db67b8d711c5710778ebc212f0f6a998e3
Acked-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Axel Haslam <axelhaslam@ti.com>
commit e71f5cc402 upstream.
per_cpu(processors, n) can be NULL, resulting in:
Loading CPUFreq modules[ 437.661360] BUG: unable to handle kernel NULL pointer dereference at (null)
IP: [<ffffffffa0434314>] pcc_cpufreq_cpu_init+0x74/0x220 [pcc_cpufreq]
It's better to avoid the oops by failing the driver, and allowing the
system to boot.
Signed-off-by: Naga Chumbalkar <nagananda.chumbalkar@hp.com>
Cc: Dave Jones <davej@codemonkey.org.uk>
Cc: Len Brown <lenb@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The interactive governor relies on quirks of the Tegra 2 cpufreq
implementation for handling SMP systems where the CPUs do not have
separate rate controls. It needs to determine the maximum rate
for all CPUs covered by the policy and set that speed.
Change-Id: I1ed9fa171e5a9c45a1fa5944e3fa823eb157e81f
Signed-off-by: Todd Poynor <toddpoynor@google.com>
Fix up checkpatch warning introduced by long lines in timer_rate
patch.
Change-Id: I22b105dafb1b49390799bb7577464da03f0f8afb
Signed-off-by: Allen Martin <amartin@nvidia.com>
Cleanup some style warnings reported by checkpatch
Change-Id: Ie2e6903d52867fb3347e009d7efa3bc4ca755cea
Signed-off-by: Allen Martin <amartin@nvidia.com>
