Merge branch 'akpm' (patches from Andrew Morton)

Merge misc fixes from Andrew Morton:
 "A few hotfixes and various leftovers which were awaiting other merges.

  Mainly movement of zram into mm/"

* emailed patches fron Andrew Morton <akpm@linux-foundation.org>: (25 commits)
  memcg: fix mutex not unlocked on memcg_create_kmem_cache fail path
  Documentation/filesystems/vfs.txt: update file_operations documentation
  mm, oom: base root bonus on current usage
  mm: don't lose the SOFT_DIRTY flag on mprotect
  mm/slub.c: fix page->_count corruption (again)
  mm/mempolicy.c: fix mempolicy printing in numa_maps
  zram: remove zram->lock in read path and change it with mutex
  zram: remove workqueue for freeing removed pending slot
  zram: introduce zram->tb_lock
  zram: use atomic operation for stat
  zram: remove unnecessary free
  zram: delay pending free request in read path
  zram: fix race between reset and flushing pending work
  zsmalloc: add maintainers
  zram: add zram maintainers
  zsmalloc: add copyright
  zram: add copyright
  zram: remove old private project comment
  zram: promote zram from staging
  zsmalloc: move it under mm
  ...
This commit is contained in:
Linus Torvalds
2014-01-30 18:44:44 -08:00
29 changed files with 154 additions and 231 deletions
+71
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@@ -0,0 +1,71 @@
zram: Compressed RAM based block devices
----------------------------------------
* Introduction
The zram module creates RAM based block devices named /dev/zram<id>
(<id> = 0, 1, ...). Pages written to these disks are compressed and stored
in memory itself. These disks allow very fast I/O and compression provides
good amounts of memory savings. Some of the usecases include /tmp storage,
use as swap disks, various caches under /var and maybe many more :)
Statistics for individual zram devices are exported through sysfs nodes at
/sys/block/zram<id>/
* Usage
Following shows a typical sequence of steps for using zram.
1) Load Module:
modprobe zram num_devices=4
This creates 4 devices: /dev/zram{0,1,2,3}
(num_devices parameter is optional. Default: 1)
2) 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.
Examples:
# Initialize /dev/zram0 with 50MB disksize
echo $((50*1024*1024)) > /sys/block/zram0/disksize
# Using mem suffixes
echo 256K > /sys/block/zram0/disksize
echo 512M > /sys/block/zram0/disksize
echo 1G > /sys/block/zram0/disksize
3) Activate:
mkswap /dev/zram0
swapon /dev/zram0
mkfs.ext4 /dev/zram1
mount /dev/zram1 /tmp
4) Stats:
Per-device statistics are exported as various nodes under
/sys/block/zram<id>/
disksize
num_reads
num_writes
invalid_io
notify_free
discard
zero_pages
orig_data_size
compr_data_size
mem_used_total
5) Deactivate:
swapoff /dev/zram0
umount /dev/zram1
6) Reset:
Write any positive value to 'reset' sysfs node
echo 1 > /sys/block/zram0/reset
echo 1 > /sys/block/zram1/reset
This frees all the memory allocated for the given device and
resets the disksize to zero. You must set the disksize again
before reusing the device.
Nitin Gupta
ngupta@vflare.org
+2 -2
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@@ -1386,8 +1386,8 @@ may allocate from based on an estimation of its current memory and swap use.
For example, if a task is using all allowed memory, its badness score will be
1000. If it is using half of its allowed memory, its score will be 500.
There is an additional factor included in the badness score: root
processes are given 3% extra memory over other tasks.
There is an additional factor included in the badness score: the current memory
and swap usage is discounted by 3% for root processes.
The amount of "allowed" memory depends on the context in which the oom killer
was called. If it is due to the memory assigned to the allocating task's cpuset
+2 -10
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@@ -782,7 +782,7 @@ struct file_operations
----------------------
This describes how the VFS can manipulate an open file. As of kernel
3.5, the following members are defined:
3.12, the following members are defined:
struct file_operations {
struct module *owner;
@@ -803,9 +803,6 @@ struct file_operations {
int (*aio_fsync) (struct kiocb *, int datasync);
int (*fasync) (int, struct file *, int);
int (*lock) (struct file *, int, struct file_lock *);
ssize_t (*readv) (struct file *, const struct iovec *, unsigned long, loff_t *);
ssize_t (*writev) (struct file *, const struct iovec *, unsigned long, loff_t *);
ssize_t (*sendfile) (struct file *, loff_t *, size_t, read_actor_t, void *);
ssize_t (*sendpage) (struct file *, struct page *, int, size_t, loff_t *, int);
unsigned long (*get_unmapped_area)(struct file *, unsigned long, unsigned long, unsigned long, unsigned long);
int (*check_flags)(int);
@@ -814,6 +811,7 @@ struct file_operations {
ssize_t (*splice_read)(struct file *, struct pipe_inode_info *, size_t, unsigned int);
int (*setlease)(struct file *, long arg, struct file_lock **);
long (*fallocate)(struct file *, int mode, loff_t offset, loff_t len);
int (*show_fdinfo)(struct seq_file *m, struct file *f);
};
Again, all methods are called without any locks being held, unless
@@ -864,12 +862,6 @@ otherwise noted.
lock: called by the fcntl(2) system call for F_GETLK, F_SETLK, and F_SETLKW
commands
readv: called by the readv(2) system call
writev: called by the writev(2) system call
sendfile: called by the sendfile(2) system call
get_unmapped_area: called by the mmap(2) system call
check_flags: called by the fcntl(2) system call for F_SETFL command