defconfig: enable blu_plug

Signed-off-by: engstk <eng.stk@sapo.pt>
cpufreq: add an helper to get/set cpu utilization to be used by mako_hotplug

Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
Signed-off-by: engstk <eng.stk@sapo.pt>
sched: LOAD_FREQ (4*HZ+61) avoids loadavg Moire. From http://ripke.com/loadavg/moire

Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
Signed-off-by: engstk <eng.stk@sapo.pt>
binfmt_elf.c: use get_random_int() to fix entropy depleting

Changes:
--------
v4->v3:
- s/random_stack_user()/get_atrandom_bytes()/
- Move this function to ahead of its use to avoid the predeclaration.

v3->v2:
- Tweak code comments of random_stack_user().
- Remove redundant bits mask and shift upon the random variable.

v2->v1:
- Fix random copy to check up buffer length that are not 4-byte multiples.

v3 can be found at:
http://www.spinics.net/lists/linux-fsdevel/msg59597.html
v2 can be found at:
http://www.spinics.net/lists/linux-fsdevel/msg59418.html
v1 can be found at:
http://www.spinics.net/lists/linux-fsdevel/msg59128.html

Thanks,
-Jeff

Entropy is quickly depleted under normal operations like ls(1), cat(1),
etc...  between 2.6.30 to current mainline, for instance:

$ cat /proc/sys/kernel/random/entropy_avail
3428
$ cat /proc/sys/kernel/random/entropy_avail
2911
$cat /proc/sys/kernel/random/entropy_avail
2620

We observed this problem has been occurring since 2.6.30 with
fs/binfmt_elf.c: create_elf_tables()->get_random_bytes(), introduced by
f06295b44c296c8f ("ELF: implement AT_RANDOM for glibc PRNG seeding").

/*
 * Generate 16 random bytes for userspace PRNG seeding.
 */
get_random_bytes(k_rand_bytes, sizeof(k_rand_bytes));

The patch introduces a wrapper around get_random_int() which has lower
overhead than calling get_random_bytes() directly.

With this patch applied:
$ cat /proc/sys/kernel/random/entropy_avail
2731
$ cat /proc/sys/kernel/random/entropy_avail
2802
$ cat /proc/sys/kernel/random/entropy_avail
2878

Analyzed by John Sobecki.

Signed-off-by: Jie Liu <jeff.liu@oracle.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andreas Dilger <aedilger@gmail.com>
Cc: Alan Cox <alan@linux.intel.com>
Cc: Arnd Bergmann <arnn@arndb.de>
Cc: John Sobecki <john.sobecki@oracle.com>
Cc: James Morris <james.l.morris@oracle.com>
Cc: Jakub Jelinek <jakub@redhat.com>
Cc: Ted Ts'o <tytso@mit.edu>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Ulrich Drepper <drepper@redhat.com>
Signed-off-by: Francisco Franco <franciscofranco.1990@gmail.com>
Signed-off-by: engstk <eng.stk@sapo.pt>
writeback: fix race that cause writeback hung

There is a race between mark inode dirty and writeback thread, see the
following scenario.  In this case, writeback thread will not run though
there is dirty_io.

__mark_inode_dirty()                                          bdi_writeback_workfn()
	...                                                       	...
	spin_lock(&inode->i_lock);
	...
	if (bdi_cap_writeback_dirty(bdi)) {
	    <<< assume wb has dirty_io, so wakeup_bdi is false.
	    <<< the following inode_dirty also have wakeup_bdi false.
	    if (!wb_has_dirty_io(&bdi->wb))
		    wakeup_bdi = true;
	}
	spin_unlock(&inode->i_lock);
	                                                            <<< assume last dirty_io is removed here.
	                                                            pages_written = wb_do_writeback(wb);
	                                                            ...
	                                                            <<< work_list empty and wb has no dirty_io,
	                                                            <<< delayed_work will not be queued.
	                                                            if (!list_empty(&bdi->work_list) ||
	                                                                (wb_has_dirty_io(wb) && dirty_writeback_interval))
	                                                                queue_delayed_work(bdi_wq, &wb->dwork,
	                                                                    msecs_to_jiffies(dirty_writeback_interval * 10));
	spin_lock(&bdi->wb.list_lock);
	inode->dirtied_when = jiffies;
	<<< new dirty_io is added.
	list_move(&inode->i_wb_list, &bdi->wb.b_dirty);
	spin_unlock(&bdi->wb.list_lock);

	<<< though there is dirty_io, but wakeup_bdi is false,
	<<< so writeback thread will not be waked up and
	<<< the new dirty_io will not be flushed.
	if (wakeup_bdi)
	    bdi_wakeup_thread_delayed(bdi);

Writeback will run until there is a new flush work queued.  This may cause
a lot of dirty pages stay in memory for a long time.

Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Fengguang Wu <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>
Signed-off-by: engstk <eng.stk@sapo.pt>
block: Reserve only one queue tag for sync IO if only 3 tags are available

In case a device has three tags available we still reserve two of them
for sync IO. That leaves only a single tag for async IO such as
writeback from flusher thread which results in poor performance.

Allow async IO to consume two tags in case queue has three tag availabe
to get a decent async write performance.

This patch improves streaming write performance on a machine with such disk
from ~21 MB/s to ~52 MB/s. Also postmark throughput in presence of
streaming writer improves from 8 to 12 transactions per second so sync
IO doesn't seem to be harmed in presence of heavy async writer.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
Signed-off-by: engstk <eng.stk@sapo.pt>
mm, vmalloc: use well-defined find_last_bit() func

Our intention in here is to find last_bit within the region to flush.
There is well-defined function, find_last_bit() for this purpose and its
performance may be slightly better than current implementation.  So change
it.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Reviewed-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
Signed-off-by: engstk <eng.stk@sapo.pt>
mm, vmalloc: remove useless variable in vmap_block

vbq in vmap_block isn't used. So remove it.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Reviewed-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
Signed-off-by: engstk <eng.stk@sapo.pt>
writeback: fix writeback cache thrashing

From: Namjae Jeon <namjae.jeon@samsung.com>

Consider Process A: huge I/O on sda
        doing heavy write operation - dirty memory becomes more
        than dirty_background_ratio
        on HDD - flusher thread flush-8:0

Consider Process B: small I/O on sdb
        doing while [1]; read 1024K + rewrite 1024K + sleep 2sec
        on Flash device - flusher thread flush-8:16

As Process A is a heavy dirtier, dirty memory becomes more
than dirty_background_thresh. Due to this, below check becomes
true(checking global_page_state in over_bground_thresh)
for all bdi devices(even for very small dirtied bdi - sdb):

In this case, even small cached data on 'sdb' is forced to flush
and writeback cache thrashing happens.

When we added debug prints inside above 'if' condition and ran
above Process A(heavy dirtier on bdi with flush-8:0) and
Process B(1024K frequent read/rewrite on bdi with flush-8:16)
we got below prints:

[Test setup: ARM dual core CPU, 512 MB RAM]

[over_bground_thresh]: wakeup flush-8:0 : BDI_RECLAIMABLE =  56064 KB
[over_bground_thresh]: wakeup flush-8:0 : BDI_RECLAIMABLE =  56704 KB
[over_bground_thresh]: wakeup flush-8:0 : BDI_RECLAIMABLE = 84720 KB
[over_bground_thresh]: wakeup flush-8:0 : BDI_RECLAIMABLE = 94720 KB
[over_bground_thresh]: wakeup flush-8:16 : BDI_RECLAIMABLE =   384 KB
[over_bground_thresh]: wakeup flush-8:16 : BDI_RECLAIMABLE =   960 KB
[over_bground_thresh]: wakeup flush-8:16 : BDI_RECLAIMABLE =    64 KB
[over_bground_thresh]: wakeup flush-8:0 : BDI_RECLAIMABLE = 92160 KB
[over_bground_thresh]: wakeup flush-8:16 : BDI_RECLAIMABLE =   256 KB
[over_bground_thresh]: wakeup flush-8:16 : BDI_RECLAIMABLE =   768 KB
[over_bground_thresh]: wakeup flush-8:16 : BDI_RECLAIMABLE =    64 KB
[over_bground_thresh]: wakeup flush-8:16 : BDI_RECLAIMABLE =   256 KB
[over_bground_thresh]: wakeup flush-8:16 : BDI_RECLAIMABLE =   320 KB
[over_bground_thresh]: wakeup flush-8:16 : BDI_RECLAIMABLE =     0 KB
[over_bground_thresh]: wakeup flush-8:0 : BDI_RECLAIMABLE = 92032 KB
[over_bground_thresh]: wakeup flush-8:0 : BDI_RECLAIMABLE = 91968 KB
[over_bground_thresh]: wakeup flush-8:16 : BDI_RECLAIMABLE =   192 KB
[over_bground_thresh]: wakeup flush-8:16 : BDI_RECLAIMABLE =  1024 KB
[over_bground_thresh]: wakeup flush-8:16 : BDI_RECLAIMABLE =    64 KB
[over_bground_thresh]: wakeup flush-8:16 : BDI_RECLAIMABLE =   192 KB
[over_bground_thresh]: wakeup flush-8:16 : BDI_RECLAIMABLE =   576 KB
[over_bground_thresh]: wakeup flush-8:16 : BDI_RECLAIMABLE =     0 KB
[over_bground_thresh]: wakeup flush-8:0 : BDI_RECLAIMABLE = 84352 KB
[over_bground_thresh]: wakeup flush-8:16 : BDI_RECLAIMABLE =   192 KB
[over_bground_thresh]: wakeup flush-8:16 : BDI_RECLAIMABLE =   512 KB
[over_bground_thresh]: wakeup flush-8:16 : BDI_RECLAIMABLE =     0 KB
[over_bground_thresh]: wakeup flush-8:0 : BDI_RECLAIMABLE = 92608 KB
[over_bground_thresh]: wakeup flush-8:0 : BDI_RECLAIMABLE = 92544 KB

As mentioned in above log, when global dirty memory > global background_thresh
small cached data is also forced to flush by flush-8:16.
If removing global background_thresh checking code, we can reduce cache
thrashing of frequently used small data.
And It will be great if we can reserve a portion of writeback cache using
min_ratio.

After applying patch:
$ echo 5 > /sys/block/sdb/bdi/min_ratio
$ cat /sys/block/sdb/bdi/min_ratio
5
[over_bground_thresh]: wakeup flush-8:0 : BDI_RECLAIMABLE =  56064 KB
[over_bground_thresh]: wakeup flush-8:0 : BDI_RECLAIMABLE =  56704 KB
[over_bground_thresh]: wakeup flush-8:0 : BDI_RECLAIMABLE =  84160 KB
[over_bground_thresh]: wakeup flush-8:0 : BDI_RECLAIMABLE =  96960 KB
[over_bground_thresh]: wakeup flush-8:0 : BDI_RECLAIMABLE =  94080 KB
[over_bground_thresh]: wakeup flush-8:0 : BDI_RECLAIMABLE =  93120 KB
[over_bground_thresh]: wakeup flush-8:0 : BDI_RECLAIMABLE =  93120 KB
[over_bground_thresh]: wakeup flush-8:0 : BDI_RECLAIMABLE =  91520 KB
[over_bground_thresh]: wakeup flush-8:0 : BDI_RECLAIMABLE =  89600 KB
[over_bground_thresh]: wakeup flush-8:0 : BDI_RECLAIMABLE =  93696 KB
[over_bground_thresh]: wakeup flush-8:0 : BDI_RECLAIMABLE =  93696 KB
[over_bground_thresh]: wakeup flush-8:0 : BDI_RECLAIMABLE =  72960 KB
[over_bground_thresh]: wakeup flush-8:0 : BDI_RECLAIMABLE =  90624 KB
[over_bground_thresh]: wakeup flush-8:0 : BDI_RECLAIMABLE =  90624 KB
[over_bground_thresh]: wakeup flush-8:0 : BDI_RECLAIMABLE =  90688 KB

As mentioned in the above logs, once cache is reserved for Process B,
and patch is applied there is less writeback cache thrashing on sdb
by frequent forced writeback by flush-8:16 in over_bground_thresh.

After all, small cached data will be flushed by periodic writeback
once every dirty_writeback_interval.

Suggested-by: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Vivek Trivedi <t.vivek@samsung.com>
Signed-off-by: Francisco Franco <franciscofranco.1990@gmail.com>
Signed-off-by: engstk <eng.stk@sapo.pt>
writeback: increase bdi_min_ratio to 5 in light of the latest writeback commit.

Signed-off-by: Francisco Franco <franciscofranco.1990@gmail.com>
Signed-off-by: engstk <eng.stk@sapo.pt>
ext4: Speedup WB_SYNC_ALL pass called from sync(2)

When doing filesystem wide sync, there's no need to force transaction
commit (or synchronously write inode buffer) separately for each inode
because ext4_sync_fs() takes care of forcing commit at the end (VFS
takes care of flushing buffer cache, respectively). Most of the time
this slowness doesn't manifest because previous WB_SYNC_NONE writeback
doesn't leave much to write but when there are processes aggressively
creating new files and several filesystems to sync, the sync slowness
can be noticeable. In the following test script sync(1) takes around 6
minutes when there are two ext4 filesystems mounted on a standard SATA
drive. After this patch sync takes a couple of seconds so we have about
two orders of magnitude improvement.

      function run_writers
      {
        for (( i = 0; i < 10; i++ )); do
          mkdir $1/dir$i
          for (( j = 0; j < 40000; j++ )); do
            dd if=/dev/zero of=$1/dir$i/$j bs=4k count=4 &>/dev/null
          done &
        done
      }

      for dir in "$@"; do
        run_writers $dir
      done

      sleep 40
      time sync

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Chet Kener <Cl3Kener@gmail.com>
Signed-off-by: flar2 <asegaert@gmail.com>
Signed-off-by: engstk <eng.stk@sapo.pt>
net: wireless: bcmdhd: Enable dongle_isolation for PCIe/built-in type driver

b/17755061 Wi-Fi stuck in Off position

Signed-off-by: Ritter Yeh <ryeh@broadcom.com>
Signed-off-by: Iliyan Malchev <malchev@google.com>
Change-Id: I70dc1385266fe26ef3a57116e653efab03fc33cf
Signed-off-by: flar2 <asegaert@gmail.com>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
Signed-off-by: engstk <eng.stk@sapo.pt>
net: wirelss: bcmdhd fixed pcie suspend/resume issue

Sometimes, system doesn't recover the config registers during resume
due to wakelock.  So, we need to save and restore the config registers in DHD

b/18220535 [WiFi] - Watchdog reset after PCIE link down and Event Hang

Signed-off-by: Ecco park <eccopark@broadcom.com>
Change-Id: Ib796b4833119a27bd79e3a667e40ee1e4d4878df
Signed-off-by: flar2 <asegaert@gmail.com>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
Signed-off-by: engstk <eng.stk@sapo.pt>
net: wireless: bcmdhd: Allow preallocation for WLFC_INFO

Bug: 18303260

Change-Id: I1602fa0706270071abe36797039af74670f1c734
Signed-off-by: Dmitry Shmidt <dimitrysh@google.com>
Signed-off-by: engstk <eng.stk@sapo.pt>

Conflicts:
	drivers/net/wireless/bcmdhd/Makefile
Signed-off-by: flar2 <asegaert@gmail.com>

Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
Signed-off-by: engstk <eng.stk@sapo.pt>
net: wireless: bcmdhd enable STATIC MEMORY ALLOCATION

b/18187102 APR: kernel BUG at mm/vmalloc.c
Signed-off-by: Ecco park <eccopark@broadcom.com>
Signed-off-by: Iliyan Malchev <malchev@google.com>
Change-Id: I9b53792487a0078ecd3240ad92e96dd702a1724b
Signed-off-by: flar2 <asegaert@gmail.com>

Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
Signed-off-by: engstk <eng.stk@sapo.pt>
net: wirelss: bcmdhd fixed disconnect issue for connecting status

Sometimes Framework issues connect and disconnect rapidly and continuously
with different APs.  In this case, the timing gap between connect and
disconnect is less than 20ms.  For this scenario, FW doesn't do anything
when DHD executes dissasoc while state of FW is associating status.  In
order to cancel current assoc procedure correctly, we need to call
scan_abort function, not DISASSOC.  FW will clean up ongoing assoc
procedure if FW is associating status.

b/18470879 Device stop responding after conducting rapid fire testing
           for making connection

Change-Id: Ib440da06eb10313c478c004d1d73ed1b4e29a201
Signed-off-by: Ecco park <eccopark@broadcom.com>
Signed-off-by: Iliyan Malchev <malchev@google.com>
Signed-off-by: engstk <eng.stk@sapo.pt>

Conflicts:
	drivers/net/wireless/bcmdhd/wl_cfg80211.c
Signed-off-by: flar2 <asegaert@gmail.com>

Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
Signed-off-by: engstk <eng.stk@sapo.pt>
net: wirelss: bcmdhd fix roaming bug

1) Bug : 18541286 wifi stuck on connected to an AP when N6 was miles away
we should update BSSID in wl_bss_roaming_done, not wl_notify_status for roaming case
It causes out-of-sync between FW and DHD
Signed-off-by: Ecco park <eccopark@broadcom.com>

Change-Id: I75e706d63aa962c8c2640797e2af6811990c989d
Signed-off-by: flar2 <asegaert@gmail.com>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
Signed-off-by: engstk <eng.stk@sapo.pt>
net: wireless: bcmdhd abort ongoing-scan for disconnection

sometimes we cannot get WLC_E_DEAUTH due to ongoing-scan
We need to abort ongoing-scan for disconnection

Bug: 18634452
Signed-off-by: Ecco park <eccopark@broadcom.com>
Change-Id: I2c416738418ce4915dcfbaa57bb3d701269eecc8
Signed-off-by: flar2 <asegaert@gmail.com>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
Signed-off-by: engstk <eng.stk@sapo.pt>
net: wireless: bcmdhd reduce kernel logging

Bug : 18226601
Signed-off-by: Ecco park <eccopark@broadcom.com>

Change-Id: Iec8172bf803b76517136d1a8903027b5ed162d31
Signed-off-by: flar2 <asegaert@gmail.com>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
Signed-off-by: engstk <eng.stk@sapo.pt>
cpufreq: cpu-boost: we can hit a small performance loss by not queuing input works less than 150ms apart when our default input work duration is only 40ms, so use that 40ms as a magic value instead of the 150ms minimum interval.

Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
Signed-off-by: engstk <eng.stk@sapo.pt>