Fix kernel-doc warnings in regulator/driver.h:
Warning(linux-next-20090108//include/linux/regulator/driver.h:95): Excess struct/union/enum/typedef member 'set_current' description in 'regulator_ops'
Warning(linux-next-20090108//include/linux/regulator/driver.h:95): Excess struct/union/enum/typedef member 'get_current' description in 'regulator_ops'
Warning(linux-next-20090108//include/linux/regulator/driver.h:124): No description found for parameter 'irq'
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
cc: Liam Girdwood <lrg@slimlogic.co.uk>
cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>
This is only the documentation that the kerneldoc system warns about.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>
Remove kerneldoc warnings that don't relate to missing documentation,
mostly by renaming parameters in the documentation to match their
actual names.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>
Add suspend/resume to the core class and remove all the now unneeded
code from various drivers. Originally the class code couldn't support
suspend/resume but since class_device can there is no reason for
each driver doing its own suspend/resume anymore.
There have been some local definitions of swap(), it's time to replace
them all with a uniform one.
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
While discussing[1] the need for glibc to have access to random bytes
during program load, it seems that an earlier attempt to implement
AT_RANDOM got stalled. This implements a random 16 byte string, available
to every ELF program via a new auxv AT_RANDOM vector.
[1] http://sourceware.org/ml/libc-alpha/2008-10/msg00006.html
Ulrich said:
glibc needs right after startup a bit of random data for internal
protections (stack canary etc). What is now in upstream glibc is that we
always unconditionally open /dev/urandom, read some data, and use it. For
every process startup. That's slow.
...
The solution is to provide a limited amount of random data to the
starting process in the aux vector. I suggested 16 bytes and this is
what the patch implements. If we need only 16 bytes or less we use the
data directly. If we need more we'll use the 16 bytes to see a PRNG.
This avoids the costly /dev/urandom use and it allows the kernel to use
the most adequate source of random data for this purpose. It might not
be the same pool as that for /dev/urandom.
Concerns were expressed about the depletion of the randomness pool. But
this patch doesn't make the situation worse, it doesn't deplete entropy
more than happens now.
Signed-off-by: Kees Cook <kees.cook@canonical.com>
Cc: Jakub Jelinek <jakub@redhat.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ulrich Drepper <drepper@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently task_active_pid_ns is not safe to call after a task becomes a
zombie and exit_task_namespaces is called, as nsproxy becomes NULL. By
reading the pid namespace from the pid of the task we can trivially solve
this problem at the cost of one extra memory read in what should be the
same cacheline as we read the namespace from.
When moving things around I have made task_active_pid_ns out of line
because keeping it in pid_namespace.h would require adding includes of
pid.h and sched.h that I don't think we want.
This change does make task_active_pid_ns unsafe to call during
copy_process until we attach a pid on the task_struct which seems to be a
reasonable trade off.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Bastian Blank <bastian@waldi.eu.org>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Nadia Derbey <Nadia.Derbey@bull.net>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
A current problem with the pid namespace is that it is easy to do pid
related work after exit_task_namespaces which drops the nsproxy pointer.
However if we are doing pid namespace related work we are always operating
on some struct pid which retains the pid_namespace pointer of the pid
namespace it was allocated in.
So provide ns_of_pid which allows us to find the pid namespace a pid was
allocated in.
Using this we have the needed infrastructure to do pid namespace related
work at anytime we have a struct pid, removing the chance of accidentally
having a NULL pointer dereference when accessing current->nsproxy.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Bastian Blank <bastian@waldi.eu.org>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Nadia Derbey <Nadia.Derbey@bull.net>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Impact: cleanups, use new cpumask API
Final trivial cleanups: mainly s/cpumask_t/struct cpumask
Note there is a FIXME in generate_sched_domains(). A future patch will
change struct cpumask *doms to struct cpumask *doms[].
(I suppose Rusty will do this.)
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Mike Travis <travis@sgi.com>
Cc: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add css_tryget(), that obtains a counted reference on a CSS. It is used
in situations where the caller has a "weak" reference to the CSS, i.e.
one that does not protect the cgroup from removal via a reference count,
but would instead be cleaned up by a destroy() callback.
css_tryget() will return true on success, or false if the cgroup is being
removed.
This is similar to Kamezawa Hiroyuki's patch from a week or two ago, but
with the difference that in the event of css_tryget() racing with a
cgroup_rmdir(), css_tryget() will only return false if the cgroup really
does get removed.
This implementation is done by biasing css->refcnt, so that a refcnt of 1
means "releasable" and 0 means "released or releasing". In the event of a
race, css_tryget() distinguishes between "released" and "releasing" by
checking for the CSS_REMOVED flag in css->flags.
Signed-off-by: Paul Menage <menage@google.com>
Tested-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
These patches introduce new locking/refcount support for cgroups to
reduce the need for subsystems to call cgroup_lock(). This will
ultimately allow the atomicity of cgroup_rmdir() (which was removed
recently) to be restored.
These three patches give:
1/3 - introduce a per-subsystem hierarchy_mutex which a subsystem can
use to prevent changes to its own cgroup tree
2/3 - use hierarchy_mutex in place of calling cgroup_lock() in the
memory controller
3/3 - introduce a css_tryget() function similar to the one recently
proposed by Kamezawa, but avoiding spurious refcount failures in
the event of a race between a css_tryget() and an unsuccessful
cgroup_rmdir()
Future patches will likely involve:
- using hierarchy mutex in place of cgroup_lock() in more subsystems
where appropriate
- restoring the atomicity of cgroup_rmdir() with respect to cgroup_create()
This patch:
Add a hierarchy_mutex to the cgroup_subsys object that protects changes to
the hierarchy observed by that subsystem. It is taken by the cgroup
subsystem (in addition to cgroup_mutex) for the following operations:
- linking a cgroup into that subsystem's cgroup tree
- unlinking a cgroup from that subsystem's cgroup tree
- moving the subsystem to/from a hierarchy (including across the
bind() callback)
Thus if the subsystem holds its own hierarchy_mutex, it can safely
traverse its own hierarchy.
Signed-off-by: Paul Menage <menage@google.com>
Tested-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Now, you can see following even when swap accounting is enabled.
1. Create Group 01, and 02.
2. allocate a "file" on tmpfs by a task under 01.
3. swap out the "file" (by memory pressure)
4. Read "file" from a task in group 02.
5. the charge of "file" is moved to group 02.
This is not ideal behavior. This is because SwapCache which was loaded
by read-ahead is not taken into account..
This is a patch to fix shmem's swapcache behavior.
- remove mem_cgroup_cache_charge_swapin().
- Add SwapCache handler routine to mem_cgroup_cache_charge().
By this, shmem's file cache is charged at add_to_page_cache()
with GFP_NOWAIT.
- pass the page of swapcache to shrink_mem_cgroup.
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Paul Menage <menage@google.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
After previous patch, mem_cgroup_try_charge is not used by anyone, so we
can remove it.
Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently, inactive_ratio of memcg is calculated at setting limit.
because page_alloc.c does so and current implementation is straightforward
porting.
However, memcg introduced hierarchy feature recently. In hierarchy
restriction, memory limit is not only decided memory.limit_in_bytes of
current cgroup, but also parent limit and sibling memory usage.
Then, The optimal inactive_ratio is changed frequently. So, everytime
calculation is better.
Tested-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently, /proc/sys/vm/swappiness can change swappiness ratio for global
reclaim. However, memcg reclaim doesn't have tuning parameter for itself.
In general, the optimal swappiness depend on workload. (e.g. hpc
workload need to low swappiness than the others.)
Then, per cgroup swappiness improve administrator tunability.
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Now, get_scan_ratio() return correct value although memcg reclaim. Then,
mem_cgroup_calc_reclaim() can be removed.
So, memcg reclaim get the same capability of anon/file reclaim balancing
as global reclaim now.
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@redhat.com>
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The inactive_anon_is_low() is key component of active/inactive anon
balancing on reclaim. However current inactive_anon_is_low() function
only consider global reclaim.
Therefore, we need following ugly scan_global_lru() condition.
if (lru == LRU_ACTIVE_ANON &&
(!scan_global_lru(sc) || inactive_anon_is_low(zone))) {
shrink_active_list(nr_to_scan, zone, sc, priority, file);
return 0;
it cause that memcg reclaim always deactivate pages when shrink_list() is
called. To make mem_cgroup_inactive_anon_is_low() improve active/inactive
anon balancing of memcgroup.
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Cyrill Gorcunov <gorcunov@gmail.com>
Cc: "Pekka Enberg" <penberg@cs.helsinki.fi>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The inactive_anon_is_low() is called only vmscan. Then it can move to
vmscan.c
This patch doesn't have any functional change.
Reviewd-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
My patch, memcg-fix-gfp_mask-of-callers-of-charge.patch changed gfp_mask
of callers of charge to be GFP_HIGHUSER_MOVABLE for showing what will
happen at memory reclaim.
But in recent discussion, it's NACKed because it sounds ugly.
This patch is for reverting it and add some clean up to gfp_mask of
callers of charge. No behavior change but need review before generating
HUNK in deep queue.
This patch also adds explanation to meaning of gfp_mask passed to charge
functions in memcontrol.h.
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Current mmtom has new oom function as pagefault_out_of_memory(). It's
added for select bad process rathar than killing current.
When memcg hit limit and calls OOM at page_fault, this handler called and
system-wide-oom handling happens. (means kernel panics if panic_on_oom is
true....)
To avoid overkill, check memcg's recent behavior before starting
system-wide-oom.
And this patch also fixes to guarantee "don't accnout against process with
TIF_MEMDIE". This is necessary for smooth OOM.
[akpm@linux-foundation.org: build fix]
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Badari Pulavarty <pbadari@us.ibm.com>
Cc: Jan Blunck <jblunck@suse.de>
Cc: Hirokazu Takahashi <taka@valinux.co.jp>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm_match_cgroup() calls cgroup_subsys_state().
We must use rcu_read_lock() to protect cgroup_subsys_state().
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Paul Menage <menage@google.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add support for building hierarchies in resource counters. Cgroups allows
us to build a deep hierarchy, but we currently don't link the resource
counters belonging to the memory controller control groups, in the same
fashion as the corresponding cgroup entries in the cgroup hierarchy. This
patch provides the infrastructure for resource counters that have the same
hiearchy as their cgroup counter parts.
These set of patches are based on the resource counter hiearchy patches
posted by Pavel Emelianov.
NOTE: Building hiearchies is expensive, deeper hierarchies imply charging
the all the way up to the root. It is known that hiearchies are
expensive, so the user needs to be careful and aware of the trade-offs
before creating very deep ones.
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Cc: Paul Menage <menage@google.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Pavel Emelianov <xemul@openvz.org>
Cc: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We check mem_cgroup is disabled or not by checking
mem_cgroup_subsys.disabled. I think it has more references than expected,
now.
replacing
if (mem_cgroup_subsys.disabled)
with
if (mem_cgroup_disabled())
give us good look, I think.
[kamezawa.hiroyu@jp.fujitsu.com: fix typo]
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
A big patch for changing memcg's LRU semantics.
Now,
- page_cgroup is linked to mem_cgroup's its own LRU (per zone).
- LRU of page_cgroup is not synchronous with global LRU.
- page and page_cgroup is one-to-one and statically allocated.
- To find page_cgroup is on what LRU, you have to check pc->mem_cgroup as
- lru = page_cgroup_zoneinfo(pc, nid_of_pc, zid_of_pc);
- SwapCache is handled.
And, when we handle LRU list of page_cgroup, we do following.
pc = lookup_page_cgroup(page);
lock_page_cgroup(pc); .....................(1)
mz = page_cgroup_zoneinfo(pc);
spin_lock(&mz->lru_lock);
.....add to LRU
spin_unlock(&mz->lru_lock);
unlock_page_cgroup(pc);
But (1) is spin_lock and we have to be afraid of dead-lock with zone->lru_lock.
So, trylock() is used at (1), now. Without (1), we can't trust "mz" is correct.
This is a trial to remove this dirty nesting of locks.
This patch changes mz->lru_lock to be zone->lru_lock.
Then, above sequence will be written as
spin_lock(&zone->lru_lock); # in vmscan.c or swap.c via global LRU
mem_cgroup_add/remove/etc_lru() {
pc = lookup_page_cgroup(page);
mz = page_cgroup_zoneinfo(pc);
if (PageCgroupUsed(pc)) {
....add to LRU
}
spin_lock(&zone->lru_lock); # in vmscan.c or swap.c via global LRU
This is much simpler.
(*) We're safe even if we don't take lock_page_cgroup(pc). Because..
1. When pc->mem_cgroup can be modified.
- at charge.
- at account_move().
2. at charge
the PCG_USED bit is not set before pc->mem_cgroup is fixed.
3. at account_move()
the page is isolated and not on LRU.
Pros.
- easy for maintenance.
- memcg can make use of laziness of pagevec.
- we don't have to duplicated LRU/Active/Unevictable bit in page_cgroup.
- LRU status of memcg will be synchronized with global LRU's one.
- # of locks are reduced.
- account_move() is simplified very much.
Cons.
- may increase cost of LRU rotation.
(no impact if memcg is not configured.)
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch implements per cgroup limit for usage of memory+swap. However
there are SwapCache, double counting of swap-cache and swap-entry is
avoided.
Mem+Swap controller works as following.
- memory usage is limited by memory.limit_in_bytes.
- memory + swap usage is limited by memory.memsw_limit_in_bytes.
This has following benefits.
- A user can limit total resource usage of mem+swap.
Without this, because memory resource controller doesn't take care of
usage of swap, a process can exhaust all the swap (by memory leak.)
We can avoid this case.
And Swap is shared resource but it cannot be reclaimed (goes back to memory)
until it's used. This characteristic can be trouble when the memory
is divided into some parts by cpuset or memcg.
Assume group A and group B.
After some application executes, the system can be..
Group A -- very large free memory space but occupy 99% of swap.
Group B -- under memory shortage but cannot use swap...it's nearly full.
Ability to set appropriate swap limit for each group is required.
Maybe someone wonder "why not swap but mem+swap ?"
- The global LRU(kswapd) can swap out arbitrary pages. Swap-out means
to move account from memory to swap...there is no change in usage of
mem+swap.
In other words, when we want to limit the usage of swap without affecting
global LRU, mem+swap limit is better than just limiting swap.
Accounting target information is stored in swap_cgroup which is
per swap entry record.
Charge is done as following.
map
- charge page and memsw.
unmap
- uncharge page/memsw if not SwapCache.
swap-out (__delete_from_swap_cache)
- uncharge page
- record mem_cgroup information to swap_cgroup.
swap-in (do_swap_page)
- charged as page and memsw.
record in swap_cgroup is cleared.
memsw accounting is decremented.
swap-free (swap_free())
- if swap entry is freed, memsw is uncharged by PAGE_SIZE.
There are people work under never-swap environments and consider swap as
something bad. For such people, this mem+swap controller extension is just an
overhead. This overhead is avoided by config or boot option.
(see Kconfig. detail is not in this patch.)
TODO:
- maybe more optimization can be don in swap-in path. (but not very safe.)
But we just do simple accounting at this stage.
[nishimura@mxp.nes.nec.co.jp: make resize limit hold mutex]
[hugh@veritas.com: memswap controller core swapcache fixes]
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
For accounting swap, we need a record per swap entry, at least.
This patch adds following function.
- swap_cgroup_swapon() .... called from swapon
- swap_cgroup_swapoff() ... called at the end of swapoff.
- swap_cgroup_record() .... record information of swap entry.
- swap_cgroup_lookup() .... lookup information of swap entry.
This patch just implements "how to record information". No actual method
for limit the usage of swap. These routine uses flat table to record and
lookup. "wise" lookup system like radix-tree requires requires memory
allocation at new records but swap-out is usually called under memory
shortage (or memcg hits limit.) So, I used static allocation. (maybe
dynamic allocation is not very hard but it adds additional memory
allocation in memory shortage path.)
Note1: In this, we use pointer to record information and this means
8bytes per swap entry. I think we can reduce this when we
create "id of cgroup" in the range of 0-65535 or 0-255.
Reported-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Reviewed-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Tested-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Reported-by: Hugh Dickins <hugh@veritas.com>
Reported-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Reported-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Pavel Emelianov <xemul@openvz.org>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Config and control variable for mem+swap controller.
This patch adds CONFIG_CGROUP_MEM_RES_CTLR_SWAP
(memory resource controller swap extension.)
For accounting swap, it's obvious that we have to use additional memory to
remember "who uses swap". This adds more overhead. So, it's better to
offer "choice" to users. This patch adds 2 choices.
This patch adds 2 parameters to enable swap extension or not.
- CONFIG
- boot option
Reviewed-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
SwapCache support for memory resource controller (memcg)
Before mem+swap controller, memcg itself should handle SwapCache in proper
way. This is cut-out from it.
In current memcg, SwapCache is just leaked and the user can create tons of
SwapCache. This is a leak of account and should be handled.
SwapCache accounting is done as following.
charge (anon)
- charged when it's mapped.
(because of readahead, charge at add_to_swap_cache() is not sane)
uncharge (anon)
- uncharged when it's dropped from swapcache and fully unmapped.
means it's not uncharged at unmap.
Note: delete from swap cache at swap-in is done after rmap information
is established.
charge (shmem)
- charged at swap-in. this prevents charge at add_to_page_cache().
uncharge (shmem)
- uncharged when it's dropped from swapcache and not on shmem's
radix-tree.
at migration, check against 'old page' is modified to handle shmem.
Comparing to the old version discussed (and caused troubles), we have
advantages of
- PCG_USED bit.
- simple migrating handling.
So, situation is much easier than several months ago, maybe.
[hugh@veritas.com: memcg: handle swap caches build fix]
Reviewed-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Tested-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Now, management of "charge" under page migration is done under following
manner. (Assume migrate page contents from oldpage to newpage)
before
- "newpage" is charged before migration.
at success.
- "oldpage" is uncharged at somewhere(unmap, radix-tree-replace)
at failure
- "newpage" is uncharged.
- "oldpage" is charged if necessary (*1)
But (*1) is not reliable....because of GFP_ATOMIC.
This patch tries to change behavior as following by charge/commit/cancel ops.
before
- charge PAGE_SIZE (no target page)
success
- commit charge against "newpage".
failure
- commit charge against "oldpage".
(PCG_USED bit works effectively to avoid double-counting)
- if "oldpage" is obsolete, cancel charge of PAGE_SIZE.
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There is a small race in do_swap_page(). When the page swapped-in is
charged, the mapcount can be greater than 0. But, at the same time some
process (shares it ) call unmap and make mapcount 1->0 and the page is
uncharged.
CPUA CPUB
mapcount == 1.
(1) charge if mapcount==0 zap_pte_range()
(2) mapcount 1 => 0.
(3) uncharge(). (success)
(4) set page's rmap()
mapcount 0=>1
Then, this swap page's account is leaked.
For fixing this, I added a new interface.
- charge
account to res_counter by PAGE_SIZE and try to free pages if necessary.
- commit
register page_cgroup and add to LRU if necessary.
- cancel
uncharge PAGE_SIZE because of do_swap_page failure.
CPUA
(1) charge (always)
(2) set page's rmap (mapcount > 0)
(3) commit charge was necessary or not after set_pte().
This protocol uses PCG_USED bit on page_cgroup for avoiding over accounting.
Usual mem_cgroup_charge_common() does charge -> commit at a time.
And this patch also adds following function to clarify all charges.
- mem_cgroup_newpage_charge() ....replacement for mem_cgroup_charge()
called against newly allocated anon pages.
- mem_cgroup_charge_migrate_fixup()
called only from remove_migration_ptes().
we'll have to rewrite this later.(this patch just keeps old behavior)
This function will be removed by additional patch to make migration
clearer.
Good for clarifying "what we do"
Then, we have 4 following charge points.
- newpage
- swap-in
- add-to-cache.
- migration.
[akpm@linux-foundation.org: add missing inline directives to stubs]
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix races between /proc/sched_debug by freeing cgroup objects via an RCU
callback. Thus any cgroup reference obtained from an RCU-safe source will
remain valid during the RCU section. Since dentries are also RCU-safe,
this allows us to traverse up the tree safely.
Additionally, make cgroup_path() check for a NULL cgrp->dentry to avoid
trying to report a path for a partially-created cgroup.
[lizf@cn.fujitsu.com: call deactive_super() in cgroup_diput()]
Signed-off-by: Paul Menage <menage@google.com>
Reviewed-by: Li Zefan <lizf@cn.fujitsu.com>
Tested-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We don't access struct cgroupfs_root in fast path, so we should not put
struct cgroupfs_root protected by RCU
But the comment in struct cgroup_subsys.root confuse us.
struct cgroup_subsys.root is used in these places:
1 find_css_set(): if (ss->root->subsys_list.next == &ss->sibling)
2 rebind_subsystems(): if (ss->root != &rootnode)
rcu_assign_pointer(ss->root, root);
rcu_assign_pointer(subsys[i]->root, &rootnode);
3 cgroup_has_css_refs(): if (ss->root != cgrp->root)
4 cgroup_init_subsys(): ss->root = &rootnode;
5 proc_cgroupstats_show(): ss->name, ss->root->subsys_bits,
ss->root->number_of_cgroups, !ss->disabled);
6 cgroup_clone(): root = subsys->root;
if ((root != subsys->root) ||
All these place we have held cgroup_lock() or we don't dereference to
struct cgroupfs_root. It's means wo don't need RCU when use struct
cgroup_subsys.root, and we should not put struct cgroupfs_root protected
by RCU.
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Reviewed-by: Paul Menage <menage@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Balbir Singh <balbir@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
At the moment there are few restrictions on which flags may be set on
which inodes. Specifically DIRSYNC may only be set on directories and
IMMUTABLE and APPEND may not be set on links. Tighten that to disallow
TOPDIR being set on non-directories and only NODUMP and NOATIME to be set
on non-regular file, non-directories.
Introduces a flags masking function which masks flags based on mode and
use it during inode creation and when flags are set via the ioctl to
facilitate future consistency.
Signed-off-by: Duane Griffin <duaneg@dghda.com>
Acked-by: Andreas Dilger <adilger@sun.com>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
At present INDEX is the only flag that new ext3 inodes do NOT inherit from
their parent. In addition prevent the flags DIRTY, ECOMPR, IMAGIC and
TOPDIR from being inherited. List inheritable flags explicitly to prevent
future flags from accidentally being inherited.
This fixes the TOPDIR flag inheritance bug reported at
http://bugzilla.kernel.org/show_bug.cgi?id=9866.
Signed-off-by: Duane Griffin <duaneg@dghda.com>
Acked-by: Andreas Dilger <adilger@sun.com>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
As spotted by kmemtrace, struct ext3_sb_info is 17152 bytes on 64-bit
which makes it a very bad fit for SLAB allocators. The culprit of the
wasted memory is ->s_blockgroup_lock which can be as big as 16 KB when
NR_CPUS >= 32.
To fix that, allocate ->s_blockgroup_lock, which fits nicely in a order 2
page in the worst case, separately. This shinks down struct ext3_sb_info
enough to fit a 1 KB slab cache so now we allocate 16 KB + 1 KB instead of
32 KB saving 15 KB of memory.
Acked-by: Andreas Dilger <adilger@sun.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There is a flaw with the way jbd handles fsync batching. If we fsync() a
file and we were not the last person to run fsync() on this fs then we
automatically sleep for 1 jiffie in order to wait for new writers to join
into the transaction before forcing the commit. The problem with this is
that with really fast storage (ie a Clariion) the time it takes to commit
a transaction to disk is way faster than 1 jiffie in most cases, so
sleeping means waiting longer with nothing to do than if we just committed
the transaction and kept going. Ric Wheeler noticed this when using
fs_mark with more than 1 thread, the throughput would plummet as he added
more threads.
This patch attempts to fix this problem by recording the average time in
nanoseconds that it takes to commit a transaction to disk, and what time
we started the transaction. If we run an fsync() and we have been running
for less time than it takes to commit the transaction to disk, we sleep
for the delta amount of time and then commit to disk. We acheive
sub-jiffie sleeping using schedule_hrtimeout. This means that the wait
time is auto-tuned to the speed of the underlying disk, instead of having
this static timeout. I weighted the average according to somebody's
comments (Andreas Dilger I think) in order to help normalize random
outliers where we take way longer or way less time to commit than the
average. I also have a min() check in there to make sure we don't sleep
longer than a jiffie in case our storage is super slow, this was requested
by Andrew.
I unfortunately do not have access to a Clariion, so I had to use a
ramdisk to represent a super fast array. I tested with a SATA drive with
barrier=1 to make sure there was no regression with local disks, I tested
with a 4 way multipathed Apple Xserve RAID array and of course the
ramdisk. I ran the following command
fs_mark -d /mnt/ext3-test -s 4096 -n 2000 -D 64 -t $i
where $i was 2, 4, 8, 16 and 32. I mkfs'ed the fs each time. Here are my
results
type threads with patch without patch
sata 2 24.6 26.3
sata 4 49.2 48.1
sata 8 70.1 67.0
sata 16 104.0 94.1
sata 32 153.6 142.7
xserve 2 246.4 222.0
xserve 4 480.0 440.8
xserve 8 829.5 730.8
xserve 16 1172.7 1026.9
xserve 32 1816.3 1650.5
ramdisk 2 2538.3 1745.6
ramdisk 4 2942.3 661.9
ramdisk 8 2882.5 999.8
ramdisk 16 2738.7 1801.9
ramdisk 32 2541.9 2394.0
Signed-off-by: Josef Bacik <jbacik@redhat.com>
Cc: Andreas Dilger <adilger@sun.com>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Ric Wheeler <rwheeler@redhat.com>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
At the moment there are few restrictions on which flags may be set on
which inodes. Specifically DIRSYNC may only be set on directories and
IMMUTABLE and APPEND may not be set on links. Tighten that to disallow
TOPDIR being set on non-directories and only NODUMP and NOATIME to be set
on non-regular file, non-directories.
Introduces a flags masking function which masks flags based on mode and
use it during inode creation and when flags are set via the ioctl to
facilitate future consistency.
Signed-off-by: Duane Griffin <duaneg@dghda.com>
Acked-by: Andreas Dilger <adilger@sun.com>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
At present BTREE/INDEX is the only flag that new ext2 inodes do NOT
inherit from their parent. In addition prevent the flags DIRTY, ECOMPR,
INDEX, IMAGIC and TOPDIR from being inherited. List inheritable flags
explicitly to prevent future flags from accidentally being inherited.
This fixes the TOPDIR flag inheritance bug reported at
http://bugzilla.kernel.org/show_bug.cgi?id=9866.
Signed-off-by: Duane Griffin <duaneg@dghda.com>
Acked-by: Andreas Dilger <adilger@sun.com>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
As spotted by kmemtrace, struct ext2_sb_info is 17024 bytes on 64-bit
which makes it a very bad fit for SLAB allocators. The culprit of the
wasted memory is ->s_blockgroup_lock which can be as big as 16 KB when
NR_CPUS >= 32.
To fix that, allocate ->s_blockgroup_lock, which fits nicely in a order 2
page in the worst case, separately. This shinks down struct ext2_sb_info
enough to fit a 1 KB slab cache so now we allocate 16 KB + 1 KB instead of
32 KB saving 15 KB of memory.
Acked-by: Andreas Dilger <adilger@sun.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The xenfs filesystem exports various interfaces to usermode. Initially
this exports a file to allow usermode to interact with xenbus/xenstore.
Traditionally this appeared in /proc/xen. Rather than extending procfs,
this patch adds a backward-compat mountpoint on /proc/xen, and provides
a xenfs filesystem which can be mounted there.
Signed-off-by: Alex Zeffertt <alex.zeffertt@eu.citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The voltage and current regulators on the WM8350 AudioPlus PMIC can be
used in concert to provide a power efficient LED driver. This driver
implements support for this within the standard LED class.
Platform initialisation code should configure the LED hardware in the
init callback provided by the WM8350 core driver. The callback should
use wm8350_isink_set_flash(), wm8350_dcdc25_set_mode() and
wm8350_dcdc_set_slot() to configure the operating parameters of the
regulators for their hardware and then then use wm8350_register_led() to
instantiate the LED driver.
This driver was originally written by Liam Girdwood, though it has been
extensively modified since then.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
Apparently these might be called under atomic context,
and i2c operations may sleep. BUG found by
Ross Burton <ross@burtonini.com>
Signed-off-by: Riku Voipio <riku.voipio@iki.fi>
Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
There is one place where the struct led_classdev as the function
argument is named differently. Fix it.
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
NOMMU mmap allocates a piece of memory for an mmap that's rounded up in size to
the nearest power-of-2 number of pages. Currently it then discards the excess
pages back to the page allocator, making that memory available for use by other
things. This can, however, cause greater amount of fragmentation.
To counter this, a sysctl is added in order to fine-tune the trimming
behaviour. The default behaviour remains to trim pages aggressively, while
this can either be disabled completely or set to a higher page-granular
watermark in order to have finer-grained control.
vm region vm_top bits taken from an earlier patch by David Howells.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Mike Frysinger <vapier.adi@gmail.com>
Make VMAs per mm_struct as for MMU-mode linux. This solves two problems:
(1) In SYSV SHM where nattch for a segment does not reflect the number of
shmat's (and forks) done.
(2) In mmap() where the VMA's vm_mm is set to point to the parent mm by an
exec'ing process when VM_EXECUTABLE is specified, regardless of the fact
that a VMA might be shared and already have its vm_mm assigned to another
process or a dead process.
A new struct (vm_region) is introduced to track a mapped region and to remember
the circumstances under which it may be shared and the vm_list_struct structure
is discarded as it's no longer required.
This patch makes the following additional changes:
(1) Regions are now allocated with alloc_pages() rather than kmalloc() and
with no recourse to __GFP_COMP, so the pages are not composite. Instead,
each page has a reference on it held by the region. Anything else that is
interested in such a page will have to get a reference on it to retain it.
When the pages are released due to unmapping, each page is passed to
put_page() and will be freed when the page usage count reaches zero.
(2) Excess pages are trimmed after an allocation as the allocation must be
made as a power-of-2 quantity of pages.
(3) VMAs are added to the parent MM's R/B tree and mmap lists. As an MM may
end up with overlapping VMAs within the tree, the VMA struct address is
appended to the sort key.
(4) Non-anonymous VMAs are now added to the backing inode's prio list.
(5) Holes may be punched in anonymous VMAs with munmap(), releasing parts of
the backing region. The VMA and region structs will be split if
necessary.
(6) sys_shmdt() only releases one attachment to a SYSV IPC shared memory
segment instead of all the attachments at that addresss. Multiple
shmat()'s return the same address under NOMMU-mode instead of different
virtual addresses as under MMU-mode.
(7) Core dumping for ELF-FDPIC requires fewer exceptions for NOMMU-mode.
(8) /proc/maps is now the global list of mapped regions, and may list bits
that aren't actually mapped anywhere.
(9) /proc/meminfo gains a line (tagged "MmapCopy") that indicates the amount
of RAM currently allocated by mmap to hold mappable regions that can't be
mapped directly. These are copies of the backing device or file if not
anonymous.
These changes make NOMMU mode more similar to MMU mode. The downside is that
NOMMU mode requires some extra memory to track things over NOMMU without this
patch (VMAs are no longer shared, and there are now region structs).
Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Mike Frysinger <vapier.adi@gmail.com>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Add support for the nwp serial device which is connected to a DCR bus. It
uses the of_serial device driver to determine necessary properties from
the device tree. The supported device is added as serial port number 85.
NWP stands for network processor and it is part of the QPACE - Quantum
Chromodynamics Parallel Computing on the Cell Broadband Engine project.
The implementation is a lightweight uart implementation with the focus
to consume as little resources as possible and it is connected to a
DCR bus.
Signed-off-by: Benjamin Krill <ben@codiert.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Randy Dunlap