mm: add a low limit to alloc_large_system_hash

UDP stack needs a minimum hash size value for proper operation and also
uses alloc_large_system_hash() for proper NUMA distribution of its hash
tables and automatic sizing depending on available system memory.

On some low memory situations, udp_table_init() must ignore the
alloc_large_system_hash() result and reallocs a bigger memory area.

As we cannot easily free old hash table, we leak it and kmemleak can
issue a warning.

This patch adds a low limit parameter to alloc_large_system_hash() to
solve this problem.

We then specify UDP_HTABLE_SIZE_MIN for UDP/UDPLite hash table
allocation.

Reported-by: Mark Asselstine <mark.asselstine@windriver.com>
Reported-by: Tim Bird <tim.bird@am.sony.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Conflicts:

	kernel/pid.c

+ testing ...
+ testing: "PM: save 8bytes in 'struct dev_pm_info'" -> https://patchwork.kernel.org/patch/1282741/
+ only for testing: v7 cache LoUIS API implementation

info: "The current cache flushing API used in cpu_suspend and __cpu_disable,
flush_cache_all(), ends up flushing the whole cache hierarchy since for
v7 it cleans and invalidates all cache levels up to Level of Coherency
(LoC) which cripples system performance when used in hot paths like hotplug
and cpuidle."

- https://patchwork.kernel.org/patch/1451311/
- https://patchwork.kernel.org/patch/1451351/
- https://patchwork.kernel.org/patch/1451341/
- https://patchwork.kernel.org/patch/1451301/
- https://patchwork.kernel.org/patch/1451321/
async: uninitialized warning corrections

The variables here are really not used uninitialized.

kernel/async.c: In function 'async_synchronize_cookie_domain':
kernel/async.c:270:10: warning: 'starttime.tv64' may be used uninitialized in this function
kernel/async.c: In function 'async_run_entry_fn':
kernel/async.c:122:10: warning: 'calltime.tv64' may be used uninitialized in this function

Signed-off-by: Vitaliy Ivanov <vitalivanov@gmail.com>
Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Signed-off-by: Viresh Kumar <viresh.kumar@st.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
kernel/async: remove redundant declaration.

It's in linux/init.h, and I'm about to change it to a bool.

Cc: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
+ fixing ...
cgroups: don't attach task to subsystem if migration failed

If a task has exited to the point it has called cgroup_exit() already,
then we can't migrate it to another cgroup anymore.

This can happen when we are attaching a task to a new cgroup between the
call to ->can_attach_task() on subsystems and the migration that is
eventually tried in cgroup_task_migrate().

In this case cgroup_task_migrate() returns -ESRCH and we don't want to
attach the task to the subsystems because the attachment to the new cgroup
itself failed.

Fix this by only calling ->attach_task() on the subsystems if the cgroup
migration succeeded.

Reported-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Ben Blum <bblum@andrew.cmu.edu>
Acked-by: Paul Menage <paul@paulmenage.org>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>