Revert "block: strict_rq affinity"

This reverts commit 093b41f68f41e7998b9a1393d32cdba0993b0668.
Revert "params: fix potential memory leak in add_sysfs_param()"

This reverts commit 6c28ed59a317fc7e16b3d00f51e9d6640b3c1884.
random: prevent add_input from doing anything
mm: writeback: tweak vm dirty ratios a little

Change-Id: I162948cb0578e82578d7cbd7cc75999550b84589
Signed-off-by: zwliew <zhaoweiliew@gmail.com>
procfs: add num_to_str() to speed up /proc/stat

== stat_check.py
num = 0
with open("/proc/stat") as f:
        while num < 1000 :
                data = f.read()
                f.seek(0, 0)
                num = num + 1
==

perf shows

    20.39%  stat_check.py  [kernel.kallsyms]    [k] format_decode
    13.41%  stat_check.py  [kernel.kallsyms]    [k] number
    12.61%  stat_check.py  [kernel.kallsyms]    [k] vsnprintf
    10.85%  stat_check.py  [kernel.kallsyms]    [k] memcpy
     4.85%  stat_check.py  [kernel.kallsyms]    [k] radix_tree_lookup
     4.43%  stat_check.py  [kernel.kallsyms]    [k] seq_printf

This patch removes most of calls to vsnprintf() by adding num_to_str()
and seq_print_decimal_ull(), which prints decimal numbers without rich
functions provided by printf().

On my 8cpu box.
== Before patch ==
[root@bluextal test]# time ./stat_check.py

real    0m0.150s
user    0m0.026s
sys     0m0.121s

== After patch ==
[root@bluextal test]# time ./stat_check.py

real    0m0.055s
user    0m0.022s
sys     0m0.030s

[akpm@linux-foundation.org: remove incorrect comment, use less statck in num_to_str(), move comment from .h to .c, simplify seq_put_decimal_ull()]
[andrea@betterlinux.com: avoid breaking the ABI in /proc/stat]
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrea Righi <andrea@betterlinux.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Glauber Costa <glommer@parallels.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Turner <pjt@google.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
backported from Linux 3.4-rc4 to Linux 3.0.x by faux123
irq: Set CPU affinity as soon as the irq thread is created

In an embedded target where IRQ affinities are pre-configured during
boot-time (and not modified through /proc/irq/../smp_affinity) during
run-time, the extra latency due to irq_thread_check_affinity can be
avoided during processing of the first interrupt with this patch.
Thoughts?

backported from Linux 3.5+ by faux123