CPU hotplug, writeback: Don't call writeback_set_ratelimit() too often during hotplug

The CPU hotplug callback related to writeback calls writeback_set_ratelimit()
during every state change in the hotplug sequence. This is unnecessary
since num_online_cpus() changes only once during the entire hotplug operation.

So invoke the function only once per hotplug, thereby avoiding the
unnecessary repetition of those costly calculations.

Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Francisco Franco <franciscofranco.1990@gmail.com>
writeback: remove nr_pages_dirtied arg from balance_dirty_pages_ratelimited_nr()

There is no reason to pass the nr_pages_dirtied argument, because
nr_pages_dirtied value from the caller is unused in
balance_dirty_pages_ratelimited_nr().

Signed-off-by: Namjae Jeon <linkinjeon@gmail.com>
Signed-off-by: Vivek Trivedi <vtrivedi018@gmail.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Francisco Franco <franciscofranco.1990@gmail.com>
cpufreq / stats: fix race between stats allocation and first usage

This patch forces complete struct cpufreq_stats allocation for all cpus before
registering CPUFREQ_TRANSITION_NOTIFIER notifier, otherwise in some conditions
cpufreq_stat_notifier_trans() can be called in the middle of stats allocation,
in this case cpufreq_stats_table already exists, but stat->freq_table is NULL.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
msm_otg: remove initialization wake_lock
misc: uidstat: avoid create_stat() race and blockage.

* create_stat() race would lead to:
  [   58.132324] proc_dir_entry 'uid_stat/10061' already registered

* blocking kmalloc reported by sbranden
 tcp_read_sock()
  uid_stat_tcp_rcv()
    create_stat()
      kmalloc(GFP_KERNEL)

Signed-off-by: JP Abgrall <jpa@google.com>
sched: Fix SCHED_HRTICK bug leading to late preemption of tasks
mm: optimize Kernel Samepage Merging(KSM)
mm: Adjust dirty writeback for IO boost
mm: Modify page_alloc to analyze zone for NULL condition before passing it on to fucntions like zone_dirty_ok.

This is trying to prevent:
Unable to handle kernel NULL pointer dereference
at virtual address 00000001' condition from PC is
at get_page_from_freelist+0xe8/0x630
LR is at zone_dirty_ok+0x18/0xe0
fs: remove some dmesg logspam from Linux mainline 3.4
fs: Modify writeback to make sure block_dump is greater than 1 rather than greater than 0 for android devices