Commit 0e06f5c0 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'akpm' (patches from Andrew) 

Merge updates from Andrew Morton:

 - a few misc bits

 - ocfs2

 - most(?) of MM

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (125 commits)
  thp: fix comments of __pmd_trans_huge_lock()
  cgroup: remove unnecessary 0 check from css_from_id()
  cgroup: fix idr leak for the first cgroup root
  mm: memcontrol: fix documentation for compound parameter
  mm: memcontrol: remove BUG_ON in uncharge_list
  mm: fix build warnings in <linux/compaction.h>
  mm, thp: convert from optimistic swapin collapsing to conservative
  mm, thp: fix comment inconsistency for swapin readahead functions
  thp: update Documentation/{vm/transhuge,filesystems/proc}.txt
  shmem: split huge pages beyond i_size under memory pressure
  thp: introduce CONFIG_TRANSPARENT_HUGE_PAGECACHE
  khugepaged: add support of collapse for tmpfs/shmem pages
  shmem: make shmem_inode_info::lock irq-safe
  khugepaged: move up_read(mmap_sem) out of khugepaged_alloc_page()
  thp: extract khugepaged from mm/huge_memory.c
  shmem, thp: respect MADV_{NO,}HUGEPAGE for file mappings
  shmem: add huge pages support
  shmem: get_unmapped_area align huge page
  shmem: prepare huge= mount option and sysfs knob
  mm, rmap: account shmem thp pages
  ...
parents f7816ad0 8f19b0c0

Documentation/blockdev/zram.txt

+46 −36
Original line number Diff line number Diff line
@@ -83,6 +83,16 @@ pre-created. Default: 1. 
	#select lzo compression algorithm

	echo lzo > /sys/block/zram0/comp_algorithm



For the time being, the `comp_algorithm' content does not necessarily

show every compression algorithm supported by the kernel. We keep this

list primarily to simplify device configuration and one can configure

a new device with a compression algorithm that is not listed in

`comp_algorithm'. The thing is that, internally, ZRAM uses Crypto API

and, if some of the algorithms were built as modules, it's impossible

to list all of them using, for instance, /proc/crypto or any other

method. This, however, has an advantage of permitting the usage of

custom crypto compression modules (implementing S/W or H/W compression).



4) Set Disksize

Set disk size by writing the value to sysfs node 'disksize'.

The value can be either in bytes or you can use mem suffixes.

Documentation/filesystems/Locking

+9 −5
Original line number Diff line number Diff line
@@ -195,7 +195,9 @@ prototypes: 
	int (*releasepage) (struct page *, int);

	void (*freepage)(struct page *);

	int (*direct_IO)(struct kiocb *, struct iov_iter *iter);

	bool (*isolate_page) (struct page *, isolate_mode_t);

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

	void (*putback_page) (struct page *);

	int (*launder_page)(struct page *);

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

	int (*error_remove_page)(struct address_space *, struct page *);
@@ -219,7 +221,9 @@ invalidatepage: yes 
releasepage:		yes

freepage:		yes

direct_IO:

isolate_page:		yes

migratepage:		yes (both)

putback_page:		yes

launder_page:		yes

is_partially_uptodate:	yes

error_remove_page:	yes
@@ -544,13 +548,13 @@ subsequent truncate), and then return with VM_FAULT_LOCKED, and the page 
locked. The VM will unlock the page.



	->map_pages() is called when VM asks to map easy accessible pages.

Filesystem should find and map pages associated with offsets from "pgoff"

till "max_pgoff". ->map_pages() is called with page table locked and must

Filesystem should find and map pages associated with offsets from "start_pgoff"

till "end_pgoff". ->map_pages() is called with page table locked and must

not block.  If it's not possible to reach a page without blocking,

filesystem should skip it. Filesystem should use do_set_pte() to setup

page table entry. Pointer to entry associated with offset "pgoff" is

passed in "pte" field in vm_fault structure. Pointers to entries for other

offsets should be calculated relative to "pte".

page table entry. Pointer to entry associated with the page is passed in

"pte" field in fault_env structure. Pointers to entries for other offsets

should be calculated relative to "pte".



	->page_mkwrite() is called when a previously read-only pte is

about to become writeable. The filesystem again must ensure that there are

Documentation/filesystems/dax.txt

+4 −2
Original line number Diff line number Diff line
@@ -49,6 +49,7 @@ These block devices may be used for inspiration: 
- axonram: Axon DDR2 device driver

- brd: RAM backed block device driver

- dcssblk: s390 dcss block device driver

- pmem: NVDIMM persistent memory driver





Implementation Tips for Filesystem Writers
@@ -75,8 +76,9 @@ calls to get_block() (for example by a page-fault racing with a read() 
or a write()) work correctly.



These filesystems may be used for inspiration:

- ext2: the second extended filesystem, see Documentation/filesystems/ext2.txt

- ext4: the fourth extended filesystem, see Documentation/filesystems/ext4.txt

- ext2: see Documentation/filesystems/ext2.txt

- ext4: see Documentation/filesystems/ext4.txt

- xfs:  see Documentation/filesystems/xfs.txt





Handling Media Errors

Documentation/filesystems/proc.txt

+9 −0
Original line number Diff line number Diff line
@@ -436,6 +436,7 @@ Private_Dirty: 0 kB 
Referenced:          892 kB

Anonymous:             0 kB

AnonHugePages:         0 kB

ShmemPmdMapped:        0 kB

Shared_Hugetlb:        0 kB

Private_Hugetlb:       0 kB

Swap:                  0 kB
@@ -464,6 +465,8 @@ accessed. 
a mapping associated with a file may contain anonymous pages: when MAP_PRIVATE

and a page is modified, the file page is replaced by a private anonymous copy.

"AnonHugePages" shows the ammount of memory backed by transparent hugepage.

"ShmemPmdMapped" shows the ammount of shared (shmem/tmpfs) memory backed by

huge pages.

"Shared_Hugetlb" and "Private_Hugetlb" show the ammounts of memory backed by

hugetlbfs page which is *not* counted in "RSS" or "PSS" field for historical

reasons. And these are not included in {Shared,Private}_{Clean,Dirty} field.
@@ -868,6 +871,9 @@ VmallocTotal: 112216 kB 
VmallocUsed:       428 kB

VmallocChunk:   111088 kB

AnonHugePages:   49152 kB

ShmemHugePages:      0 kB

ShmemPmdMapped:      0 kB





    MemTotal: Total usable ram (i.e. physical ram minus a few reserved

              bits and the kernel binary code)
@@ -912,6 +918,9 @@ MemAvailable: An estimate of how much memory is available for starting new 
AnonHugePages: Non-file backed huge pages mapped into userspace page tables

      Mapped: files which have been mmaped, such as libraries

       Shmem: Total memory used by shared memory (shmem) and tmpfs

ShmemHugePages: Memory used by shared memory (shmem) and tmpfs allocated

              with huge pages

ShmemPmdMapped: Shared memory mapped into userspace with huge pages

        Slab: in-kernel data structures cache

SReclaimable: Part of Slab, that might be reclaimed, such as caches

  SUnreclaim: Part of Slab, that cannot be reclaimed on memory pressure

Documentation/filesystems/vfs.txt

+11 −0
Original line number Diff line number Diff line
@@ -592,9 +592,14 @@ struct address_space_operations { 
	int (*releasepage) (struct page *, int);

	void (*freepage)(struct page *);

	ssize_t (*direct_IO)(struct kiocb *, struct iov_iter *iter);

	/* isolate a page for migration */

	bool (*isolate_page) (struct page *, isolate_mode_t);

	/* migrate the contents of a page to the specified target */

	int (*migratepage) (struct page *, struct page *);

	/* put migration-failed page back to right list */

	void (*putback_page) (struct page *);

	int (*launder_page) (struct page *);



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

					unsigned long);

	void (*is_dirty_writeback) (struct page *, bool *, bool *);
@@ -747,6 +752,10 @@ struct address_space_operations { 
        and transfer data directly between the storage and the

        application's address space.



  isolate_page: Called by the VM when isolating a movable non-lru page.

	If page is successfully isolated, VM marks the page as PG_isolated

	via __SetPageIsolated.



  migrate_page:  This is used to compact the physical memory usage.

        If the VM wants to relocate a page (maybe off a memory card

        that is signalling imminent failure) it will pass a new page
@@ -754,6 +763,8 @@ struct address_space_operations { 
	transfer any private data across and update any references

        that it has to the page.



  putback_page: Called by the VM when isolated page's migration fails.



  launder_page: Called before freeing a page - it writes back the dirty page. To

  	prevent redirtying the page, it is kept locked during the whole

	operation.

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