fs/super.c: sync ro remount after blocking writers

Move sync_filesystem() after sb_prepare_remount_readonly().  If writers
sneak in anywhere from sync_filesystem() to sb_prepare_remount_readonly()
it can cause inodes to be dirtied and writeback to occur well after
sys_mount() has completely successfully.

This was spotted by corrupted ubifs filesystems on reboot, but appears
that it can cause issues with any filesystem using writeback.

Cc: Artem Bityutskiy <dedekind1@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
CC: Richard Weinberger <richard@nod.at>
Co-authored-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Andrew Ruder <andrew.ruder@elecsyscorp.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
msm: rq_stats: update related_cpus in the cpu_load runtime

"related_cpu" indicates the list of CPUs that need some
sort of frequency coordination, whether software or hardware.
ex:- if all cpus shares the same clock, all 4 cpus belongs to
related_cpus.

cpufreq driver updates the related_cpus during hotplug offline/online
events. Hence update related_cpus for all cpus during hotplug notifier.

CRs-fixed: 548631
Change-Id: I6543ddaeebf73d18334066b090ee7c4a72466e4a
Signed-off-by: Anji Jonnala <anjir@codeaurora.org>
msm: msm_rq_stats: remove is_smp() API

is_smp() API is unavailable on few target codes.
Until this API is defined use CONFIG_SMP to know
whether target supports SPM are not.

CRs-fixed: 579034
Change-Id: I5bd5c208b18aae27d7f36e77e9d5b38639c2c00e
Signed-off-by: Murali Nalajala <mnalajal@codeaurora.org>
msm: rq_stats: Use cpufreq API to get the current frequency

Since the acpuclock APIs are deprecated, use the cpufreq to
get the current frequency of CPUs to calculate the cpu
normalized load value.

Change-Id: I6e381d584d6725ef964bad86c835d44f3046e9c3
Signed-off-by: Archana Sathyakumar <asathyak@codeaurora.org>
msm: rq_stats: Fix wrong usage of cpufreq_quick_get()

cpufreq_quick_get() returns frequency in KHz, which is exactly what
cur_freq expect. Remove the wrong multiplication.

CRs-fixed: 645518
Change-Id: Ia8b080a188023964f5eee77c8586828097d11ad4
Signed-off-by: Junjie Wu <junjiew@codeaurora.org>

Conflicts:
	arch/arm/mach-msm/msm_rq_stats.c
soc: qcom: rq_stats: remove the redundant iowait check

Iowait_time check is redundant and it would lead to heavy load
due to miscaluculation of idle time. Hence remove this check
as iowait will considered based on io_busy flag.

Change-Id: I4dd9f9c79205eca588daea8cc0fe892394a83391
CRs-fixed: 662052
Signed-off-by: Anji Jonnala <anjir@codeaurora.org>
[zwliew: Backported to previous RQ stat driver in MSM]
Signed-off-by: Zhao Wei Liew <zhaoweiliew@gmail.com>

Conflicts:
	arch/arm/mach-msm/msm_rq_stats.c