ext4: speed up truncate/unlink by not using bforget() unless needed

Do not iterate over data blocks scanning for bh's to forget as they're
never exist. This improves time taken by unlink / truncate syscall.
Tested by continuously truncating file that is being written by dd.
Another test is rm -rf of linux tree while tar unpacks it. With
ordered data mode condition unlikely(!tbh) was always met in
ext4_free_blocks. With journal data mode tbh was found only few times,
so optimisation is also possible.

Unlinking fallocated 60G file after doing sync && echo 3 >
/proc/sys/vm/drop_caches && time rm --help

X86 before (linux 3.6-rc4):
# time rm -f test1
real    0m2.710s
user    0m0.000s
sys     0m1.530s

X86 after:
# time rm -f test1
real    0m0.644s
user    0m0.003s
sys     0m0.060s

MIPS before (linux 2.6.37):
# time rm -f test1
real    0m 4.93s
user    0m 0.00s
sys     0m 4.61s

MIPS after:
# time rm -f test1
real    0m 0.16s
user    0m 0.00s
sys     0m 0.06s

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Andrey Sidorov <qrxd43@motorola.com>
Signed-off-by: flar2 <asegaert@gmail.com>
af_unix: speedup /proc/net/unix /proc/net/unix has quadratic behavior, and can hold unix_table_lock for a while if high number of unix sockets are alive. (90 ms for 200k sockets...)

We already have a hash table, so its quite easy to use it.

Problem is unbound sockets are still hashed in a single hash slot
(unix_socket_table[UNIX_HASH_TABLE])

This patch also spreads unbound sockets to 256 hash slots, to speedup
both /proc/net/unix and unix_diag.

Time to read /proc/net/unix with 200k unix sockets :
(time dd if=/proc/net/unix of=/dev/null bs=4k)

before : 520 secs
after : 2 secs

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: flar2 <asegaert@gmail.com>
net: loopback: set default mtu to 64K

loopback current mtu of 16436 bytes allows no more than 3 MSS TCP
segments per frame, or 48 Kbytes. Changing mtu to 64K allows TCP
stack to build large frames and significantly reduces stack overhead.

Performance boost on bulk TCP transferts can be up to 30 %, partly
because we now have one ACK message for two 64KB segments, and a lower
probability of hitting /proc/sys/net/ipv4/tcp_reordering default limit.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: flar2 <asegaert@gmail.com>
ASoc: Reduce number of periods in low latency driver.

- Reduce number of periods to 2 from 4.

Signed-off-by: SathishKumar Mani <smani@codeaurora.org>
Signed-off-by: flar2 <asegaert@gmail.com>
ASoc: msm: Increase max buffer size to 4k for lowlatency playback

- Small buffersize is resulting in scheduling issues.
- Increase max buffer size so that user space can
  configure large buffer size to avoid scheduling
  issues.

bug-id: 6865729
Signed-off-by: SathishKumar Mani <smani@codeaurora.org>
Signed-off-by: flar2 <asegaert@gmail.com>
ASoC: msm: Reduce min buffer size for low latency

The current low latency driver has 512 bytes as
the min buffer size threshold. With this reducing
the playback time to lower values is not possible.
Setting it to 128 bytes gives us more room
to try out lower buffer sizes from the user space

Signed-off-by: Alexy Joseph <alexyj@codeaurora.org>
Signed-off-by: Mekala Natarajan <mekalan@codeaurora.org>
Signed-off-by: flar2 <asegaert@gmail.com>
ASoC: msm: Change QOS value for low latency path

There were variations in the time taken to
return from each write. This was due
to the delay in switching in and out of
power collapse. To manage this set QOS
value to 1ms so that the core has enough
time to wake up from power collapse

Signed-off-by: Alexy Joseph <alexyj@codeaurora.org>
Signed-off-by: Mekala Natarajan <mekalan@codeaurora.org>
Signed-off-by: flar2 <asegaert@gmail.com>
arm/dt: msm8974: Increase "ib" values for VIDC DDR bandwidth request

As per the recommendation by performance team, update the
"ib" values for DDR BW requests. This change fixes the
display under-runs seen during video playback.

Change-Id: I137814c82b257b8c751dab9df4f705e43fd5643e
Signed-off-by: Vinay Kalia <vkalia@codeaurora.org>
Signed-off-by: flar2 <asegaert@gmail.com>
USB: f_mtp: Set maximum burst value to two for superspeed mode

Currently burst value is set to zero for superspeed in mtp driver.
MTP throughput can be improved by setting max burst vlaue to non
zero value in superspeed mode. Hence set max burst vlaue to two
for both IN and OUT bulk endpoints in superspeed mode.

CRs-Fixed: 532070
Change-Id: Ib78b8fec5d1ab934f4d4ec80b7e008149707ce0f
Signed-off-by: Vijayavardhan Vennapusa <vvreddy@codeaurora.org>
Signed-off-by: flar2 <asegaert@gmail.com>
USB: gadget: rndis: Optimize tx path for better performance

Current rndis header addition and aggregation steps:
1. Increase skb headroom by size of rndis header.
2. Copy skb data with newly created skb having more headroom.
3. Create and add rndis header with it.
4. Again copy skb data with usb request buffer for aggregation purpose.

New optimized steps :
1. Create and copy rndis header directly with usb request buffer
2. Copy skb data with usb request buffer

Above new steps avoids cpu intensive skb operations which reduces CPU
usage and provide better throughput.

This change also assigns completion handle with usb request at the time
of usb request creation instead of assigning everytime before queueing
usb request.

CRs-Fixed: 551363
Change-Id: Ifc64d6a8573f6a24e28c73ef9a19b62649e171cd
Signed-off-by: Mayank Rana <mrana@codeaurora.org>
Signed-off-by: flar2 <asegaert@gmail.com>
ASoC: msm: Add 24 bit support to Primary MI2S TX

Add 24 bit support to Primary MI2S Tx. Add
capability to specify bits per sample to DSP.

Change-Id: I928f37c7b76ffea735365b164d52ceabd88e77e6
Signed-off-by: Damir Didjusto <damird@codeaurora.org>
Signed-off-by: flar2 <asegaert@gmail.com>
cpuidle: make a single register function for all

The usual scheme to initialize a cpuidle driver on a SMP is:

	cpuidle_register_driver(drv);
	for_each_possible_cpu(cpu) {
		device = &per_cpu(cpuidle_dev, cpu);
		cpuidle_register_device(device);
	}

This code is duplicated in each cpuidle driver.

On UP systems, it is done this way:

	cpuidle_register_driver(drv);
	device = &per_cpu(cpuidle_dev, cpu);
	cpuidle_register_device(device);

On UP, the macro 'for_each_cpu' does one iteration:

        for ((cpu) = 0; (cpu) < 1; (cpu)++, (void)mask)

Hence, the initialization loop is the same for UP than SMP.

Beside, we saw different bugs / mis-initialization / return code unchecked in
the different drivers, the code is duplicated including bugs. After fixing all
these ones, it appears the initialization pattern is the same for everyone.

Please note, some drivers are doing dev->state_count = drv->state_count. This is
not necessary because it is done by the cpuidle_enable_device function in the
cpuidle framework. This is true, until you have the same states for all your
devices. Otherwise, the 'low level' API should be used instead with the specific
initialization for the driver.

Let's add a wrapper function doing this initialization with a cpumask parameter
for the coupled idle states and use it for all the drivers.

That will save a lot of LOC, consolidate the code, and the modifications in the
future could be done in a single place. Another benefit is the consolidation of
the cpuidle_device variable which is now in the cpuidle framework and no longer
spread accross the different arch specific drivers.

Change-Id: I8f75188d5770871620f758c2973b74384ac570d5
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Karthik Parsha <kparsha@codeaurora.org>
Signed-off-by: Mahesh Sivasubramanian <msivasub@codeaurora.org>
Signed-off-by: flar2 <asegaert@gmail.com>
tick: Dynamically set broadcast irq affinity

When a cpu goes to a deep idle state where its local timer is
shutdown, it notifies the time frame work to use the broadcast timer
instead.  Unfortunately, the broadcast device could wake up any CPU,
including an idle one which is not concerned by the wake up at all. So
in the worst case an idle CPU will wake up to send an IPI to the CPU
whose timer expired.

Provide an opt-in feature CLOCK_EVT_FEAT_DYNIRQ which tells the core
that is should set the interrupt affinity of the broadcast interrupt
to the cpu which has the earliest expiry time. This avoids unnecessary
spurious wakeups and IPIs.

[ tglx: Adopted to cpumask rework, silenced an uninitialized warning,
  massaged changelog ]

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: viresh.kumar@linaro.org
Cc: jacob.jun.pan@linux.intel.com
Cc: linux-arm-kernel@lists.infradead.org
Cc: santosh.shilimkar@ti.com
Cc: linaro-kernel@lists.linaro.org
Cc: patches@linaro.org
Cc: rickard.andersson@stericsson.com
Cc: vincent.guittot@linaro.org
Cc: linus.walleij@stericsson.com
Cc: john.stultz@linaro.org
Link: http://lkml.kernel.org/r/1362219013-18173-3-git-send-email-daniel.lezcano@linaro.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

Change-Id: I6a880a39dd595526b80a6d72b88be74163513da9
Signed-off-by: Karthik Parsha <kparsha@codeaurora.org>
Signed-off-by: Mahesh Sivasubramanian <msivasub@codeaurora.org>
Signed-off-by: flar2 <asegaert@gmail.com>
net: wireless: bcmdhd: support Hotspot 2.0 release 1.0

Change-Id: I0d893b85741da628cb5c49c0a1b70c9d2d1ffac9
Signed-off-by: Ecco Park <eccopark@broadcom.com>
Signed-off-by: Dmitry Shmidt <dimitrysh@google.com>
Signed-off-by: flar2 <asegaert@gmail.com>
msm: Increase the kernel virtual area to include lowmem

Even though lowmem is accounted for in vmalloc space, allocation
comes only from the region bounded by VMALLOC_START and VMALLOC_END.
The kernel virtual area can now allocate from any unmapped region
starting from PAGE_OFFSET.

Change-Id: I291b9eb443d3f7445fd979bd7b09e9241ff22ba3
Signed-off-by: Neeti Desai <neetid@codeaurora.org>
Signed-off-by: flar2 <asegaert@gmail.com>
msm: Allow lowmem to be non contiguous and mixed.

Any image that is expected to have a lifetime of
the entire system can give the virtual address
space back for use in vmalloc.

Change-Id: I81ce848cd37e8573d706fa5d1aa52147b3c8da12
Signed-off-by: Neeti Desai <neetid@codeaurora.org>
Signed-off-by: flar2 <asegaert@gmail.com>
Kconfig: Enable config to allow vmalloc savings

Select the config to reclaim the vmalloc space in lowmem
and disable the map around the hole config, where selected,
as both the configs cannot be enabled together

CRs-Fixed: 568470
Change-Id: I9dd3e0123e4fe3e33554cdbdf5a82e344c230f47
Signed-off-by: Neeti Desai <neetid@codeaurora.org>
Signed-off-by: flar2 <asegaert@gmail.com>
Kconfig: Add config option to support vmalloc savings

The virtual space belonging to any subsystem which is
expected to have a lifetime of the entire system can be
reclaimed. Adding config option to enable or disable
this feature.

Change-Id: I56faef4b71c948185fdfe336054a5951dfa8d011
Signed-off-by: Neeti Desai <neetid@codeaurora.org>
Signed-off-by: flar2 <asegaert@gmail.com>
Kconfig: Add menu choice option to reclaim virtual memory

Add menu choice options for selecting the method of reclaiming
virtual memory, either by mapping around the largest hole or
reclaiming virtual memory belonging to any subsystem expected to
have a lifetime of the entire system. By default virtual memory
is not reclaimed.

Change-Id: I1b8a1492062bb9532700122878618989e5148647
Signed-off-by: Neeti Desai <neetid@codeaurora.org>
Signed-off-by: flar2 <asegaert@gmail.com>
sched: reinitialize rq->next_balance when a CPU is hot-added

Reinitialize rq->next_balance when a CPU is hot-added.  Otherwise,
scheduler domain rebalancing may be skipped if rq->next_balance was
set to a future time when the CPU was last active, and the
newly-re-added CPU is in idle_balance().  As a result, the
newly-re-added CPU will remain idle with no tasks scheduled until the
softlockup watchdog runs - potentially 4 seconds later.  This can
waste energy and reduce performance.

This behavior can be observed in some SoC kernels, which use CPU
hotplug to dynamically remove and add CPUs in response to load.  In
one case that triggered this behavior,

0. the system started with all cores enabled, running multi-threaded
   CPU-bound code;

1. the system entered some single-threaded code;

2. a CPU went idle and was hot-removed;

3. the system started executing a multi-threaded CPU-bound task;

4. the CPU from event 2 was re-added, to respond to the load.

The time interval between events 2 and 4 was approximately 300
milliseconds.

Of course, ideally CPU hotplug would not be used in this manner,
but this patch does appear to fix a real bug.

Nvidia folks: this patch is submitted as at least a partial fix for
bug 1243368 ("[sched] Load-balancing not happening correctly after
cores brought online")

Change-Id: Iabac21e110402bb581b7db40c42babc951d378d0
Signed-off-by: Paul Walmsley <pwalmsley@nvidia.com>
Cc: Peter Boonstoppel <pboonstoppel@nvidia.com>
Reviewed-on: http://git-master/r/208927
Reviewed-by: Automatic_Commit_Validation_User
Reviewed-by: Peter Zu <pzu@nvidia.com>
Reviewed-by: Peter Boonstoppel <pboonstoppel@nvidia.com>
GVS: Gerrit_Virtual_Submit
Tested-by: Peter Zu <pzu@nvidia.com>
Reviewed-by: Yu-Huan Hsu <yhsu@nvidia.com>
Signed-off-by: flar2 <asegaert@gmail.com>