Commit ac694dbd authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'akpm' (Andrew's patch-bomb) 

Merge Andrew's second set of patches:
 - MM
 - a few random fixes
 - a couple of RTC leftovers

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (120 commits)
  rtc/rtc-88pm80x: remove unneed devm_kfree
  rtc/rtc-88pm80x: assign ret only when rtc_register_driver fails
  mm: hugetlbfs: close race during teardown of hugetlbfs shared page tables
  tmpfs: distribute interleave better across nodes
  mm: remove redundant initialization
  mm: warn if pg_data_t isn't initialized with zero
  mips: zero out pg_data_t when it's allocated
  memcg: gix memory accounting scalability in shrink_page_list
  mm/sparse: remove index_init_lock
  mm/sparse: more checks on mem_section number
  mm/sparse: optimize sparse_index_alloc
  memcg: add mem_cgroup_from_css() helper
  memcg: further prevent OOM with too many dirty pages
  memcg: prevent OOM with too many dirty pages
  mm: mmu_notifier: fix freed page still mapped in secondary MMU
  mm: memcg: only check anon swapin page charges for swap cache
  mm: memcg: only check swap cache pages for repeated charging
  mm: memcg: split swapin charge function into private and public part
  mm: memcg: remove needless !mm fixup to init_mm when charging
  mm: memcg: remove unneeded shmem charge type
  ...
parents a40a1d3d 437ea90c

Documentation/ABI/obsolete/proc-sys-vm-nr_pdflush_threads

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What:		/proc/sys/vm/nr_pdflush_threads

Date:		June 2012

Contact:	Wanpeng Li <liwp@linux.vnet.ibm.com>

Description: Since pdflush is replaced by per-BDI flusher, the interface of old pdflush

             exported in /proc/sys/vm/ should be removed.

Documentation/cgroups/hugetlb.txt

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HugeTLB Controller

-------------------



The HugeTLB controller allows to limit the HugeTLB usage per control group and

enforces the controller limit during page fault. Since HugeTLB doesn't

support page reclaim, enforcing the limit at page fault time implies that,

the application will get SIGBUS signal if it tries to access HugeTLB pages

beyond its limit. This requires the application to know beforehand how much

HugeTLB pages it would require for its use.



HugeTLB controller can be created by first mounting the cgroup filesystem.



# mount -t cgroup -o hugetlb none /sys/fs/cgroup



With the above step, the initial or the parent HugeTLB group becomes

visible at /sys/fs/cgroup. At bootup, this group includes all the tasks in

the system. /sys/fs/cgroup/tasks lists the tasks in this cgroup.



New groups can be created under the parent group /sys/fs/cgroup.



# cd /sys/fs/cgroup

# mkdir g1

# echo $$ > g1/tasks



The above steps create a new group g1 and move the current shell

process (bash) into it.



Brief summary of control files



 hugetlb.<hugepagesize>.limit_in_bytes     # set/show limit of "hugepagesize" hugetlb usage

 hugetlb.<hugepagesize>.max_usage_in_bytes # show max "hugepagesize" hugetlb  usage recorded

 hugetlb.<hugepagesize>.usage_in_bytes     # show current res_counter usage for "hugepagesize" hugetlb

 hugetlb.<hugepagesize>.failcnt		   # show the number of allocation failure due to HugeTLB limit



For a system supporting two hugepage size (16M and 16G) the control

files include:



hugetlb.16GB.limit_in_bytes

hugetlb.16GB.max_usage_in_bytes

hugetlb.16GB.usage_in_bytes

hugetlb.16GB.failcnt

hugetlb.16MB.limit_in_bytes

hugetlb.16MB.max_usage_in_bytes

hugetlb.16MB.usage_in_bytes

hugetlb.16MB.failcnt

Documentation/cgroups/memory.txt

+7 −5
Original line number Diff line number Diff line
@@ -73,6 +73,8 @@ Brief summary of control files. 


 memory.kmem.tcp.limit_in_bytes  # set/show hard limit for tcp buf memory

 memory.kmem.tcp.usage_in_bytes  # show current tcp buf memory allocation

 memory.kmem.tcp.failcnt            # show the number of tcp buf memory usage hits limits

 memory.kmem.tcp.max_usage_in_bytes # show max tcp buf memory usage recorded



1. History
@@ -187,12 +189,12 @@ the cgroup that brought it in -- this will happen on memory pressure). 
But see section 8.2: when moving a task to another cgroup, its pages may

be recharged to the new cgroup, if move_charge_at_immigrate has been chosen.



Exception: If CONFIG_CGROUP_CGROUP_MEM_RES_CTLR_SWAP is not used.

Exception: If CONFIG_CGROUP_CGROUP_MEMCG_SWAP is not used.

When you do swapoff and make swapped-out pages of shmem(tmpfs) to

be backed into memory in force, charges for pages are accounted against the

caller of swapoff rather than the users of shmem.



2.4 Swap Extension (CONFIG_CGROUP_MEM_RES_CTLR_SWAP)

2.4 Swap Extension (CONFIG_MEMCG_SWAP)



Swap Extension allows you to record charge for swap. A swapped-in page is

charged back to original page allocator if possible.
@@ -259,7 +261,7 @@ When oom event notifier is registered, event will be delivered. 
  per-zone-per-cgroup LRU (cgroup's private LRU) is just guarded by

  zone->lru_lock, it has no lock of its own.



2.7 Kernel Memory Extension (CONFIG_CGROUP_MEM_RES_CTLR_KMEM)

2.7 Kernel Memory Extension (CONFIG_MEMCG_KMEM)



With the Kernel memory extension, the Memory Controller is able to limit

the amount of kernel memory used by the system. Kernel memory is fundamentally
@@ -286,8 +288,8 @@ per cgroup, instead of globally. 


a. Enable CONFIG_CGROUPS

b. Enable CONFIG_RESOURCE_COUNTERS

c. Enable CONFIG_CGROUP_MEM_RES_CTLR

d. Enable CONFIG_CGROUP_MEM_RES_CTLR_SWAP (to use swap extension)

c. Enable CONFIG_MEMCG

d. Enable CONFIG_MEMCG_SWAP (to use swap extension)



1. Prepare the cgroups (see cgroups.txt, Why are cgroups needed?)

# mount -t tmpfs none /sys/fs/cgroup

Documentation/feature-removal-schedule.txt

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@@ -13,6 +13,14 @@ Who: Jim Cromie <jim.cromie@gmail.com>, Jason Baron <jbaron@redhat.com> 


---------------------------



What: /proc/sys/vm/nr_pdflush_threads

When: 2012

Why: Since pdflush is deprecated, the interface exported in /proc/sys/vm/

     should be removed.

Who: Wanpeng Li <liwp@linux.vnet.ibm.com>



---------------------------



What:	CONFIG_APM_CPU_IDLE, and its ability to call APM BIOS in idle

When:	2012

Why:	This optional sub-feature of APM is of dubious reliability,

Documentation/filesystems/Locking

+13 −0
Original line number Diff line number Diff line
@@ -206,6 +206,8 @@ prototypes: 
	int (*launder_page)(struct page *);

	int (*is_partially_uptodate)(struct page *, read_descriptor_t *, unsigned long);

	int (*error_remove_page)(struct address_space *, struct page *);

	int (*swap_activate)(struct file *);

	int (*swap_deactivate)(struct file *);



locking rules:

	All except set_page_dirty and freepage may block
@@ -229,6 +231,8 @@ migratepage: yes (both) 
launder_page:		yes

is_partially_uptodate:	yes

error_remove_page:	yes

swap_activate:		no

swap_deactivate:	no



	->write_begin(), ->write_end(), ->sync_page() and ->readpage()

may be called from the request handler (/dev/loop).
@@ -330,6 +334,15 @@ cleaned, or an error value if not. Note that in order to prevent the page 
getting mapped back in and redirtied, it needs to be kept locked

across the entire operation.



	->swap_activate will be called with a non-zero argument on

files backing (non block device backed) swapfiles. A return value

of zero indicates success, in which case this file can be used for

backing swapspace. The swapspace operations will be proxied to the

address space operations.



	->swap_deactivate() will be called in the sys_swapoff()

path after ->swap_activate() returned success.



----------------------- file_lock_operations ------------------------------

prototypes:

	void (*fl_copy_lock)(struct file_lock *, struct file_lock *);

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