fs: vfat: reduce the worst case latencies

When a block partition is mounted with FAT file system
and MS_DIRSYNC option is used, some file system operations
like create, rename shall sleep in caller's context until
all the metadata have been committed to the non-volatile memory.
Since this operation is blocking call for user context,
the WRITE_SYNC option must be used instead of WRITE
(async operation) which incur inherent latencies while
flushing the meta-data corresponding to directory entries

Change-Id: I41c514889873a39d564271db0a421e6c66e5ae33
Signed-off-by: xiaogang <xiaogang@codeaurora.org>
readahead: fault retry breaks mmap file read random detection

.fault now can retry.  The retry can break state machine of .fault.  In
filemap_fault, if page is miss, ra->mmap_miss is increased.  In the second
try, since the page is in page cache now, ra->mmap_miss is decreased.  And
these are done in one fault, so we can't detect random mmap file access.

Add a new flag to indicate .fault is tried once.  In the second try, skip
ra->mmap_miss decreasing.  The filemap_fault state machine is ok with it.

I only tested x86, didn't test other archs, but looks the change for other
archs is obvious, but who knows :)

Signed-off-by: Shaohua Li <shaohua.li@xxxxxxxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxx>
Cc: Wu Fengguang <fengguang.wu@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
modified for Tuna kernel from Linux Mainline by faux123
add simple GPU governor
KGSL: make simple govenor a selectable option, co-exist with ondemand

also removed some hardcoded values

Signed-off-by: Paul Reioux <reioux@gmail.com>
KGSL: simple governor: expose tunables to sysfs interface via module_param

Signed-off-by: Paul Reioux <reioux@gmail.com>
KGSL: Simple Governor: fix minor logic issue

Signed-off-by: Paul Reioux <reioux@gmail.com>