linux-hardened/include
Rafael J. Wysocki 9a15fb2c79 cpufreq: Drop the 'initialized' field from struct cpufreq_governor
The 'initialized' field in struct cpufreq_governor is only used by
the conservative governor (as a usage counter) and the way that
happens is far from straightforward and arguably incorrect.

Namely, the value of 'initialized' is checked by
cpufreq_dbs_governor_init() and cpufreq_dbs_governor_exit() and
the results of those checks are passed (as the second argument) to
the ->init() and ->exit() callbacks in struct dbs_governor.  Those
callbacks are only implemented by the ondemand and conservative
governors and ondemand doesn't use their second argument at all.
In turn, the conservative governor uses it to decide whether or not
to either register or unregister a transition notifier.

That whole mechanism is not only unnecessarily convoluted, but also
racy, because the 'initialized' field of struct cpufreq_governor is
updated in cpufreq_init_governor() and cpufreq_exit_governor() under
policy->rwsem which doesn't help if one of these functions is run
twice in parallel for different policies (which isn't impossible in
principle), for example.

Instead of it, add a proper usage counter to the conservative
governor and update it from cs_init() and cs_exit() which is
guaranteed to be non-racy, as those functions are only called
under gov_dbs_data_mutex which is global.

With that in place, drop the 'initialized' field from struct
cpufreq_governor as it is not used any more.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2016-06-02 23:24:39 +02:00
..
acpi libnvdimm for 4.7 2016-05-23 11:18:01 -07:00
asm-generic Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-05-25 17:11:43 -07:00
clocksource clocksource: arm_arch_timer: Remove arch_timer_get_timecounter 2016-05-03 12:54:21 +02:00
crypto Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2016-05-19 09:21:36 -07:00
drm Merge tag 'drm-intel-next-fixes-2016-05-25' of git://anongit.freedesktop.org/drm-intel into drm-next 2016-05-27 16:08:38 +10:00
dt-bindings Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux 2016-05-26 09:23:43 -07:00
keys
kvm KVM: arm/arm64: vgic-new: implement mapped IRQ handling 2016-05-20 15:40:09 +02:00
linux cpufreq: Drop the 'initialized' field from struct cpufreq_governor 2016-06-02 23:24:39 +02:00
math-emu
media [media] media: rc: reduce size of struct ir_raw_event 2016-05-07 10:34:17 -03:00
memory
misc cxl: Add kernel API to allow a context to operate with relocate disabled 2016-05-11 21:54:10 +10:00
net net: sock: move ->sk_shutdown out of bitfields. 2016-05-20 18:05:32 -04:00
pcmcia
ras
rdma IB/core: Make device counter infrastructure dynamic 2016-05-26 12:52:51 -04:00
rxrpc
scsi Merge branch '4.7/scsi-queue' of git://git.kernel.org/pub/scm/linux/kernel/git/mkp/scsi into for-4.7-zac 2016-05-09 12:34:39 -04:00
soc ARC updates for 4.7-rc1 2016-05-19 09:46:18 -07:00
sound ASoC: Updates for v4.7 2016-05-16 14:59:00 +02:00
target Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending 2016-05-28 12:04:17 -07:00
trace - move kvm_stat tool from QEMU repo into tools/kvm/kvm_stat 2016-05-27 13:41:54 -07:00
uapi sound updates #2 for 4.7-rc1 2016-05-28 12:23:12 -07:00
video imx-drm probing fix 2016-05-25 12:36:20 +10:00
xen
Kbuild