lib/string & lib/memcpy: use GNU implementation.

Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
Asynchronous I/O latency to a solid-state disk greatly increased
between the 2.6.32 and 3.0 kernels. By removing the plug from
do_io_submit(), we observed a 34% improvement in the I/O latency.

Unfortunately, at this level, we don't know if the request is to
a rotating disk or not.

Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Cc: linux-aio@kvack.org
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
sched: Prevent wakeup to enter critical section needlessly

Check the waitqueue task list to be non empty before entering the critical
section. This prevents locking the spin lock needlessly in case the queue
was empty, and therefor also prevent scheduling overhead on a PREEMPT_RT
system.

Signed-off-by: Ivo Sieben <meltedpianoman@gmail.com>
backported from Linux 3.5+ by faux123
timers: Avoid finding cpu for migration of running timers in __mod_timer()

Currently we don't support migration of currently running timers. Current code
flow in __mod_timer() is:
- Find a cpu where we should migrate the timer
- Check if timer is currently running
- If yes, don't migrate.

In this process, the first step is a unnecessary activiy, if the timer is
currently running. This patch tries to avoid it in such cases.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
backported from Linux 3.5+ by faux123
Added optimized ARM RWSEM algorithm.
Added optimized CRC32 algorithm.
staging: android: Reduced Android Logger RAM usage

Change-Id: Iab33abb47f17b175ebd3da5f17c926c1929f060c

Conflicts:
	drivers/staging/android/logger.c

commit a339661e0fad9ea5fc5051ae84a3c05db33569c3 1 parent d027765
dorimanx authored 3 months ago loosethisskin committed 8 days ago
Fix merge/build