Revert "futexes: Fix futex_hashsize initialization"

This reverts commit b34868d4c05bb6f23ce73f0aba1663a29098d5a9.
Revert "futexes: Avoid taking the hb->lock if there's nothing to wake up"

This reverts commit 9cf083c635f5b3e8e70c9b90b06374dd5bb28709.
Revert "futexes: Document multiprocessor ordering guarantees"

This reverts commit a10a7c0eff364aefa7a5fa8bfcda5bd455af9cfd.
Revert "futexes: Increase hash table size for better performance"

This reverts commit 9f704fa09043cbeacb8f7c5fb62ce4ce5242d811.
Revert "futexes: Clean up various details"

This reverts commit cf172425c9a6cb30808b702c48d2c0eb191dab4d.
Revert "futex: fix kernel-doc notation and spello"

This reverts commit 5ac02afed0f3f84a9a729d531f422ed7422a65d4.
tty: remove smux debugging
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>
debug: remove: remove some dmesg logspam from Linux mainline 3.4 fs
debug: remove: arm unwind: remove logspam while in debug mode

Change-Id: I87501ca4609a883a99cddd2836c5d036e2cacd06
kernel: printk: Implement configurable DEFAULT_CONSOLE_LOGLEVEL
kernel: printk: set default console log level to 4

loglevel=       All Kernel Messages with a loglevel smaller than the
                    console loglevel will be printed to the console. It can
                    also be changed with klogd or other programs. The
                    loglevels are defined as follows:

                    0 (KERN_EMERG)          system is unusable
                    1 (KERN_ALERT)          action must be taken immediately
                    2 (KERN_CRIT)           critical conditions
                    3 (KERN_ERR)            error conditions
                    4 (KERN_WARNING)        warning conditions
                    5 (KERN_NOTICE)         normal but significant condition
                    6 (KERN_INFO)           informational
                    7 (KERN_DEBUG)          debug-level messages
audit: disable log spam messages
sched: Add sysinterface for GENTLE_FAIR_SLEEPERS

Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
Signed-off-by: Luka Karinja <lk@varjanta.com>
hrtimer: Introduce effective timer slack

task_get_effective_timer_slack() returns timer slack value to be used
to configure per-task timers. It can be equal or higher than task's
timer slack value.

For now task_get_effective_timer_slack() returns timer_slack_ns of the
task. Timer slack cgroup controller will implement a bit more
sophisticated logic.

Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name>
Signed-off-by: Cristoforo Cataldo <cristoforo.cataldo@gmail.com>
Revert "hrtimer: Introduce effective timer slack"

This reverts commit 57dc79174a268b0a95ab3f8761b6e82b0806e83e.
sched: LOAD_FREQ (4*HZ+61) avoids loadavg Moire

These values are applicable for 100 HZ device.
Check http://ripke.com/loadavg/moire for more details.

Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
staging: android: Fix three checkpatch issues in binder.c

Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
block: account iowait time when waiting for completion of IO request

Using wait_for_completion() for waiting for a IO request to be executed
results in wrong iowait time accounting. For example, a system having
the only task doing write() and fdatasync() on a block device can be
reported being idle instead of iowaiting as it should because
blkdev_issue_flush() calls wait_for_completion() which in turn calls
schedule() that does not increment the iowait proc counter and thus does
not turn on iowait time accounting.

The patch makes block layer use wait_for_completion_io() instead of
wait_for_completion() where appropriate to account iowait time
correctly.

Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>
ext4: remove useless marking of superblock dirty

Commit a0375156 properly notes that superblock doesn't need to be marked
as dirty when only number of free inodes / blocks / number of directories
changes since that is recomputed on each mount anyway. However that comment
leaves some unnecessary markings as dirty in place. Remove these.

Artem: tested using xfstests for both journalled and non-journalled ext4.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Tested-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>