Commit Graph

218419 Commits

Author SHA1 Message Date
Namhyung Kim 81d3285c96 ptrace: cleanup arch_ptrace() on frv
Use new 'regno', 'datap' variables in order to remove duplicated
expressions and unnecessary castings. Alse remove checking @addr
less than 0 because addr is now unsigned.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Cc: David Howells <dhowells@redhat.com>
Cc: "Daniel K." <dk@uw.no>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:10 -07:00
Namhyung Kim 475a4b8138 ptrace: cleanup arch_ptrace() on cris
Use new 'regno' variable in order to remove redandunt expression and
remove checking @addr less than 0 because @addr is now unsigned.  Also
update 'datap' on PTRACE_GET/SETREGS to fix a bug on arch-v10.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Acked-by: Mikael Starvik <starvik@axis.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:10 -07:00
Namhyung Kim aeebd3a3d9 ptrace: cleanup arch_ptrace() and friends on Blackfin
Change signature of get/put_reg() according to the change of arch_ptrace()
and remove unnecessary castings.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:10 -07:00
Namhyung Kim 9f29b8fb41 ptrace: cleanup arch_ptrace() on avr32
use new 'datap' variable type of void pointer in order to remove unnecessary
castings.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Acked-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: Hans-Christian Egtvedt <hans-christian.egtvedt@atmel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:10 -07:00
Namhyung Kim b640a0d192 ptrace: cleanup arch_ptrace() on ARM
use new 'datap' variable in order to remove unnecessary castings.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Cc: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:10 -07:00
Namhyung Kim eb5a369931 ptrace: cleanup arch_ptrace() on x86
Remove checking @addr less than 0 because @addr is now unsigned and
use new udescp variable in order to remove unnecessary castings.

[akpm@linux-foundation.org: fix unused variable 'udescp']
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:10 -07:00
Namhyung Kim 9b05a69e05 ptrace: change signature of arch_ptrace()
Fix up the arguments to arch_ptrace() to take account of the fact that
@addr and @data are now unsigned long rather than long as of a preceding
patch in this series.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Cc: <linux-arch@vger.kernel.org>
Acked-by: Roland McGrath <roland@redhat.com>
Acked-by: David Howells <dhowells@redhat.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:10 -07:00
Namhyung Kim 9fed81dc40 ptrace: cleanup ptrace_request()
Use new 'datavp' and 'datalp' variables to remove unnecesary castings.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:10 -07:00
Namhyung Kim 4abf986960 ptrace: change signature of sys_ptrace() and friends
Since userspace API of ptrace syscall defines @addr and @data as void
pointers, it would be more appropriate to define them as unsigned long in
kernel.  Therefore related functions are changed also.

'unsigned long' is typically used in other places in kernel as an opaque
data type and that using this helps cleaning up a lot of warnings from
sparse.

Suggested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:10 -07:00
Namhyung Kim c4b5ed250e ptrace: annotate lock context change on exit_ptrace()
exit_ptrace() releases and regrabs tasklist_lock but was missing proper
annotation.  Add it.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Acked-by: Roland McGrath <roland@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Oleg Nesterov <oleg@redhat.com
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:10 -07:00
KAMEZAWA Hiroyuki 26174efd42 memcg: generic filestat update interface
This patch extracts the core logic from mem_cgroup_update_file_mapped() as
mem_cgroup_update_file_stat() and adds a wrapper.

As a planned future update, memory cgroup has to count dirty pages to
implement dirty_ratio/limit.  And more, the number of dirty pages is
required to kick flusher thread to start writeback.  (Now, no kick.)

This patch is preparation for it and makes other statistics implementation
clearer.  Just a clean up.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com>
Reviewed-by: Greg Thelen <gthelen@google.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:10 -07:00
KAMEZAWA Hiroyuki 1489ebad8b memcg: cpu hotplug aware quick acount_move detection
An event counter MEM_CGROUP_ON_MOVE is used for quick check whether file
stat update can be done in async manner or not.  Now, it use percpu
counter and for_each_possible_cpu to update.

This patch replaces for_each_possible_cpu to for_each_online_cpu and adds
necessary synchronization logic at CPU HOTPLUG.

[akpm@linux-foundation.org: coding-style fixes]
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>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:09 -07:00
KAMEZAWA Hiroyuki 711d3d2c9b memcg: cpu hotplug aware percpu count updates
Now, memcgroup's per cpu coutner uses for_each_possible_cpu() to get the
value.  It's better to use for_each_online_cpu() and a cpu hotplug
handler.

This patch only handles statistics counter.  MEM_CGROUP_ON_MOVE will be
handled in another patch.

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>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:09 -07:00
KAMEZAWA Hiroyuki 7d74b06f24 memcg: use for_each_mem_cgroup
In memory cgroup management, we sometimes have to walk through
subhierarchy of cgroup to gather informaiton, or lock something, etc.

Now, to do that, mem_cgroup_walk_tree() function is provided.  It calls
given callback function per cgroup found.  But the bad thing is that it
has to pass a fixed style function and argument, "void*" and it adds much
type casting to memcontrol.c.

To make the code clean, this patch replaces walk_tree() with

  for_each_mem_cgroup_tree(iter, root)

An iterator style call.  The good point is that iterator call doesn't have
to assume what kind of function is called under it.  A bad point is that
it may cause reference-count leak if a caller use "break" from the loop by
mistake.

I think the benefit is larger.  The modified code seems straigtforward and
easy to read because we don't have misterious callbacks and pointer cast.

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>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:09 -07:00
KAMEZAWA Hiroyuki 32047e2a85 memcg: avoid lock in updating file_mapped (Was fix race in file_mapped accouting flag management
At accounting file events per memory cgroup, we need to find memory cgroup
via page_cgroup->mem_cgroup.  Now, we use lock_page_cgroup() for guarantee
pc->mem_cgroup is not overwritten while we make use of it.

But, considering the context which page-cgroup for files are accessed,
we can use alternative light-weight mutual execusion in the most case.

At handling file-caches, the only race we have to take care of is "moving"
account, IOW, overwriting page_cgroup->mem_cgroup.  (See comment in the
patch)

Unlike charge/uncharge, "move" happens not so frequently. It happens only when
rmdir() and task-moving (with a special settings.)
This patch adds a race-checker for file-cache-status accounting v.s. account
moving. The new per-cpu-per-memcg counter MEM_CGROUP_ON_MOVE is added.
The routine for account move
  1. Increment it before start moving
  2. Call synchronize_rcu()
  3. Decrement it after the end of moving.
By this, file-status-counting routine can check it needs to call
lock_page_cgroup(). In most case, I doesn't need to call it.

Following is a perf data of a process which mmap()/munmap 32MB of file cache
in a minute.

Before patch:
    28.25%     mmap  mmap               [.] main
    22.64%     mmap  [kernel.kallsyms]  [k] page_fault
     9.96%     mmap  [kernel.kallsyms]  [k] mem_cgroup_update_file_mapped
     3.67%     mmap  [kernel.kallsyms]  [k] filemap_fault
     3.50%     mmap  [kernel.kallsyms]  [k] unmap_vmas
     2.99%     mmap  [kernel.kallsyms]  [k] __do_fault
     2.76%     mmap  [kernel.kallsyms]  [k] find_get_page

After patch:
    30.00%     mmap  mmap               [.] main
    23.78%     mmap  [kernel.kallsyms]  [k] page_fault
     5.52%     mmap  [kernel.kallsyms]  [k] mem_cgroup_update_file_mapped
     3.81%     mmap  [kernel.kallsyms]  [k] unmap_vmas
     3.26%     mmap  [kernel.kallsyms]  [k] find_get_page
     3.18%     mmap  [kernel.kallsyms]  [k] __do_fault
     3.03%     mmap  [kernel.kallsyms]  [k] filemap_fault
     2.40%     mmap  [kernel.kallsyms]  [k] handle_mm_fault
     2.40%     mmap  [kernel.kallsyms]  [k] do_page_fault

This patch reduces memcg's cost to some extent.
(mem_cgroup_update_file_mapped is called by both of map/unmap)

Note: It seems some more improvements are required..but no idea.
      maybe removing set/unset flag is required.

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>
Cc: Greg Thelen <gthelen@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:09 -07:00
KAMEZAWA Hiroyuki 0c270f8f99 memcg: fix race in file_mapped accouting flag management
Presently memory cgroup accounts file-mapped by counter and flag.  counter
is working in the same way with zone_stat but FileMapped flag only exists
in memcg (for helping move_account).

This flag can be updated wrongly in a case.  Assume CPU0 and CPU1 and a
thread mapping a page on CPU0, another thread unmapping it on CPU1.

    CPU0                   		CPU1
				rmv rmap (mapcount 1->0)
   add rmap (mapcount 0->1)
   lock_page_cgroup()
   memcg counter+1		(some delay)
   set MAPPED FLAG.
   unlock_page_cgroup()
				lock_page_cgroup()
				memcg counter-1
				clear MAPPED flag

In the above sequence counter is properly updated but FLAG is not.  This
means that representing a state by a flag which is maintained by counter
needs some special care.

To handle this, when clearing a flag, this patch check mapcount directly
and clear the flag only when mapcount == 0.  (if mapcount >0, someone will
make it to zero later and flag will be cleared.)

Reverse case, dec-after-inc cannot be a problem because page_table_lock()
works well for it.  (IOW, to make above sequence, 2 processes should touch
the same page at once with map/unmap.)

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: Greg Thelen <gthelen@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:09 -07:00
Daniel Lezcano 45531757b4 cgroup: notify ns_cgroup deprecated
The ns_cgroup will be removed very soon.  Let's warn, for this version,
ns_cgroup is deprecated.

Make ns_cgroup and clone_children exclusive.  If the clone_children is set
and the ns_cgroup is mounted, let's fail with EINVAL when the ns_cgroup
subsys is created (a printk will help the user to understand why the
creation fails).

Update the feature remove schedule file with the deprecated ns_cgroup.

Signed-off-by: Daniel Lezcano <daniel.lezcano@free.fr>
Acked-by: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:09 -07:00
Evgeny Kuznetsov f4a2589fea cgroups: add check for strcpy destination string overflow
Function "strcpy" is used without check for maximum allowed source string
length and could cause destination string overflow.  Check for string
length is added before using "strcpy".  Function now is return error if
source string length is more than a maximum.

akpm: presently considered NotABug, but add the check for general
future-safeness and robustness.

Signed-off-by: Evgeny Kuznetsov <EXT-Eugeny.Kuznetsov@nokia.com>
Acked-by: Paul Menage <menage@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:09 -07:00
Daniel Lezcano 32a8cf235e cgroup: make the mount options parsing more accurate
Current behavior:
=================

(1) When we mount a cgroup, we can specify the 'all' option which
    means to enable all the cgroup subsystems.  This is the default option
    when no option is specified.

(2) If we want to mount a cgroup with a subset of the supported cgroup
    subsystems, we have to specify a subsystems name list for the mount
    option.

(3) If we specify another option like 'noprefix' or 'release_agent',
    the actual code wants the 'all' or a subsystem name option specified
    also.  Not critical but a bit not friendly as we should assume (1) in
    this case.

(4) Logically, the 'all' option is mutually exclusive with a subsystem
    name, but this is not detected.

In other words:
 succeed : mount -t cgroup -o all,freezer cgroup /cgroup
	=> is it 'all' or 'freezer' ?
 fails : mount -t cgroup -o noprefix cgroup /cgroup
	=> succeed if we do '-o noprefix,all'

The following patches consolidate a bit the mount options check.

New behavior:
=============

(1) untouched
(2) untouched
(3) the 'all' option will be by default when specifying other than
    a subsystem name option
(4) raises an error

In other words:
 fails   : mount -t cgroup -o all,freezer cgroup /cgroup
 succeed : mount -t cgroup -o noprefix cgroup /cgroup

For the sake of lisibility, the if ... then ... else ... if ...
indentation when parsing the options has been changed to:
if ... then
	...
	continue
fi

Signed-off-by: Daniel Lezcano <daniel.lezcano@free.fr>
Signed-off-by: Serge E. Hallyn <serge.hallyn@canonical.com>
Reviewed-by: Li Zefan <lizf@cn.fujitsu.com>
Reviewed-by: Paul Menage <menage@google.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Jamal Hadi Salim <hadi@cyberus.ca>
Cc: Matt Helsley <matthltc@us.ibm.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>
2010-10-27 18:03:09 -07:00
Daniel Lezcano 97978e6d1f cgroup: add clone_children control file
The ns_cgroup is a control group interacting with the namespaces.  When a
new namespace is created, a corresponding cgroup is automatically created
too.  The cgroup name is the pid of the process who did 'unshare' or the
child of 'clone'.

This cgroup is tied with the namespace because it prevents a process to
escape the control group and use the post_clone callback, so the child
cgroup inherits the values of the parent cgroup.

Unfortunately, the more we use this cgroup and the more we are facing
problems with it:

(1) when a process unshares, the cgroup name may conflict with a
    previous cgroup with the same pid, so unshare or clone return -EEXIST

(2) the cgroup creation is out of control because there may have an
    application creating several namespaces where the system will
    automatically create several cgroups in his back and let them on the
    cgroupfs (eg.  a vrf based on the network namespace).

(3) the mix of (1) and (2) force an administrator to regularly check
    and clean these cgroups.

This patchset removes the ns_cgroup by adding a new flag to the cgroup and
the cgroupfs mount option.  It enables the copy of the parent cgroup when
a child cgroup is created.  We can then safely remove the ns_cgroup as
this flag brings a compatibility.  We have now to manually create and add
the task to a cgroup, which is consistent with the cgroup framework.

This patch:

Sent as an answer to a previous thread around the ns_cgroup.

https://lists.linux-foundation.org/pipermail/containers/2009-June/018627.html

It adds a control file 'clone_children' for a cgroup.  This control file
is a boolean specifying if the child cgroup should be a clone of the
parent cgroup or not.  The default value is 'false'.

This flag makes the child cgroup to call the post_clone callback of all
the subsystem, if it is available.

At present, the cpuset is the only one which had implemented the
post_clone callback.

The option can be set at mount time by specifying the 'clone_children'
mount option.

Signed-off-by: Daniel Lezcano <daniel.lezcano@free.fr>
Signed-off-by: Serge E. Hallyn <serge.hallyn@canonical.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Acked-by: Paul Menage <menage@google.com>
Reviewed-by: Li Zefan <lizf@cn.fujitsu.com>
Cc: Jamal Hadi Salim <hadi@cyberus.ca>
Cc: Matt Helsley <matthltc@us.ibm.com>
Acked-by: 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>
2010-10-27 18:03:09 -07:00
Tomasz Buchert 2d3cbf8bc8 cgroup_freezer: update_freezer_state() does incorrect state transitions
There are 4 state transitions possible for a freezer.  Only FREEZING ->
FROZEN transaction is done lazily.  This patch allows update_freezer_state
only to perform this transaction and renames the function to
update_if_frozen.

Moreover is_task_frozen_enough function is removed and its every occurence
is replaced with frozen().  Therefore for a group to become FROZEN every
task must be frozen.

The previous version could trigger a following bug: When cgroup is in the
process of freezing (but none of its tasks are frozen yet),
update_freezer_state() (called from freezer_read or freezer_write) would
incorrectly report that a group is 'THAWED' (because nfrozen = 0),
allowing the transaction FREEZING -> THAWED without writing anything to
'freezer.state'.  This is incorrect according to the documentation.  This
could result in a 'THAWED' cgroup with frozen tasks inside.

A code to reproduce this bug is available here:
http://pentium.hopto.org/~thinred/repos/linux-misc/freezer_bug2.c

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Tomasz Buchert <tomasz.buchert@inria.fr>
Cc: Matt Helsley <matthltc@us.ibm.com>
Cc: Paul Menage <menage@google.com>
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>
2010-10-27 18:03:08 -07:00
Tomasz Buchert 0bdba580ab cgroup_freezer: fix can_attach() to prohibit moving from/to freezing/frozen cgroups
It is possible to move a task from its cgroup even if this group is
'FREEZING'.  This results in a nasty bug - the moved task will become
frozen OUTSIDE its original cgroup and will remain in a permanent 'D'
state.

This patch allows to migrate the task only between THAWED cgroups.

This behavior was observed and easily reproduced on a single core laptop.
Notice that reproducibility depends highly on the machine used.  Program
and instructions how to reproduce the bug can be fetched from:
http://pentium.hopto.org/~thinred/repos/linux-misc/freezer_bug.c

Signed-off-by: Tomasz Buchert <tomasz.buchert@inria.fr>
Cc: Matt Helsley <matthltc@us.ibm.com>
Cc: Paul Menage <menage@google.com>
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>
2010-10-27 18:03:08 -07:00
Tomasz Buchert d5de4ddb1b cgroup_freezer: unnecessary test in cgroup_freezing_or_frozen()
The root freezer_state is always CGROUP_THAWED so we can remove the
special case from the code.  The test itself can be handy and is extracted
to static function.

Signed-off-by: Tomasz Buchert <tomasz.buchert@inria.fr>
Cc: Matt Helsley <matthltc@us.ibm.com>
Cc: Paul Menage <menage@google.com>
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>
2010-10-27 18:03:08 -07:00
Andrea Righi abffc0207f doc: clarify the behaviour of dirty_ratio/dirty_bytes
When dirty_ratio or dirty_bytes is written the other parameter is disabled
and set to 0 (in dirty_bytes_handler() / dirty_ratio_handler()).

We do the same for dirty_background_ratio and dirty_background_bytes.

However, in the sysctl documentation, we say that the counterpart becomes
a function of the old value, that is not correct.

Clarify the documentation reporting the actual behaviour.

Reviewed-by: Greg Thelen <gthelen@google.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Andrea Righi <arighi@develer.com>
Cc: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:08 -07:00
Ondrej Zary e45c9effed isofs: work-around for Rock Ridge+Joliet CDs with empty ISO root directory
If a CD has both Rock Ridge and Joliet extensions and the ISO root
directory is empty, no files are visible.  Disable Rock Ridge extensions
in this case and use Joliet root directory instead.

Signed-off-by: Ondrej Zary <linux@rainbow-software.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Guenter Roeck <guenter.roeck@ericsson.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:08 -07:00
Nicolas Kaiser b4754ebc31 drivers/video/omap/blizzard.c: suspected typo in assignment
Untested, but looks like an obvious typo to me.

Signed-off-by: Nicolas Kaiser <nikai@nikai.net>
Cc: Tomi Valkeinen <tomi.valkeinen@nokia.com>
Cc: Tony Lindgren <tony@atomide.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:08 -07:00
Julia Lawall f35691062a drivers/video/gbefb.c: eliminate memory leak
This code is preceded by a call to framebuffer_alloc, which allocates
memory, so this memory should be freed before leaving the function in an
error case.  out_release_framebuffer just frees the frame buffer and
returns.

A simplified version of the semantic match that finds this problem is:
(http://coccinelle.lip6.fr/)

// <smpl>
@r exists@
local idexpression x;
expression E;
identifier f1;
iterator I;
@@

x = framebuffer_alloc(...);
<... when != x
     when != true (x == NULL || ...)
     when != if (...) { <+...x...+> }
     when != I (...) { <+...x...+> }
(
 x == NULL
|
 x == E
|
 x->f1
)
...>
* return ...;
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Arnaud Patard <arnaud.patard@rtp-net.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:08 -07:00
James Hogan f11b478d46 fbmem: fix fb_read, fb_write unaligned accesses
fb_{read,write} access the framebuffer using lots of fb_{read,write}l's
but don't check that the file position is aligned which can cause problems
on some architectures which do not support unaligned accesses.

Since the operations are essentially memcpy_{from,to}io, new
fb_memcpy_{from,to}fb macros have been defined and these are used instead.

For Sparc, fb_{read,write} macros use sbus_{read,write}, so this defines
new sbus_memcpy_{from,to}io functions the same as memcpy_{from,to}io but
using sbus_{read,write}b instead of {read,write}b.

Signed-off-by: James Hogan <james@albanarts.com>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:08 -07:00
James Hogan c9c62dce35 fbmem: fix whitespace
Change a few lines of indentation to tabs.

Signed-off-by: James Hogan <james@albanarts.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:08 -07:00
Julia Lawall 847fb8aca3 drivers/video/matrox/matroxfb_maven.c: fix unsigned return type
The function has an unsigned return type, but returns a negative constant
to indicate an error condition.  The result of calling the function is
only tested by comparison to 0, and thus unsigned is not needed and can be
dropped from the return type.

A sematic match that finds this problem is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@exists@
identifier f;
constant C;
@@

 unsigned f(...)
 { <+...
*  return -C;
 ...+> }
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Cc: Petr Vandrovec <vandrove@vc.cvut.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:08 -07:00
Ondrej Zary f0a2f357d4 savagefb: fix DDC for Savage 4
I tested savagefb on 3 different Savage 4 cards:
Diamond Stealth III S520
Number Nine SR9
Datapath Horizon 2S (two savage chips on a PCI card)

it worked except the DDC which did not work on any of them.

Looking at the BIOS code, it does not use MMIO register 0xff20 but CRT
register 0xa0 or 0xb1 - depending on the chip revision and something in
register 0xa6.  With this patch, DDC works fine on all 3 cards (even on
the second head of Horizon 2S - although it does not display anything as
it's misconfigured because of missing BIOS).

Signed-off-by: Ondrej Zary <linux@rainbow-software.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:08 -07:00
Christian Dietrich 09b599ddd4 drivers/video/matrox/matroxfb_DAC1064.c: remove undead ifdef CONFIG_FB_MATROX_G
The CONFIG_FB_MATROX_G ifdef isn't necessary at this point, because it is
checked in an outer ifdef level already and has no effect here.

Signed-off-by: Christian Dietrich <qy03fugy@stud.informatik.uni-erlangen.de>
Acked-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:07 -07:00
Alan Cox 72b4379e95 langwell_gpio: add support for whitney point
In this case the logic is very similar but the IRQs are not exposed and
the device is not picked up via PCI

Based on a separate internal whitney point driver by Yin Kangkai.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Cc: Yin Kangkai <kangkai.yin@intel.com>
Cc: Alek Du <alek.du@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:07 -07:00
Andrew Morton fd0574cb54 drivers/gpio/langwell_gpio.c: remove semicolons after function definitions
Deweird this driver.

Cc: Alek Du <alek.du@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:07 -07:00
Tomoya MORINAGA 04c17aa893 gpio: add Topcliff PCH GPIO driver
Topcliff PCH is the platform controller hub that is going to be used in
Intel's upcoming general embedded platform.  All IO peripherals in
Topcliff PCH are actually devices sitting on AMBA bus.  Topcliff PCH has
GPIO I/F.  Using this I/F, it is able to access system devices connected
to GPIO.

[akpm@linux-foundation.org: ese DEFINE_PCI_DEVICE_TABLE (per Joe Perches)]
Signed-off-by: Tomoya MORINAGA <tomoya-linux@dsn.okisemi.com>
Reviewed-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: Rabin Vincent <rabin.vincent@stericsson.com>
Cc: Samuel Ortiz <sameo@linux.intel.com>
Cc: Linus Walleij <linus.walleij@stericsson.com>
Cc: Tomoya MORINAGA <morinaga526@dsn.okisemi.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:07 -07:00
Michael Hennerich dc5ae4f2f5 gpio: adp5588-gpio: add i2c forward declaration
Some ADP5588 functions take a pointer to an i2c_client, but if the i2c
header doesn't happen to be included first, we hit the standard "struct
declared inside parameter list" warnings from gcc.  So add a simple
forward decl of the i2c_client struct.

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:07 -07:00
Michael Hennerich 9ef8c8c51a gpio: adp5588-gpio: gpio_start must be signed
Common code interprets this as a signed value (a negative value is used to
request dynamic ID allocation), so make sure the platform data has proper
types to support that.

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:07 -07:00
Michael Hennerich 459773ae8d gpio: adp5588-gpio: support interrupt controller
Implement irq_chip functionality on ADP5588/5587 GPIO expanders.  Only
level sensitive interrupts are supported.  Interrupts provided by this
irq_chip must be requested using request_threaded_irq().

Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:07 -07:00
Miguel Gaio ead6db0843 gpio: add support for 74x164 serial-in/parallel-out 8-bit shift register
Add support for generic 74x164 serial-in/parallel-out 8-bits shift
register.  This driver can be used as a GPIO output expander.

[akpm@linux-foundation.org: remove unused local `refresh']
Signed-off-by: Miguel Gaio <miguel.gaio@efixo.com>
Signed-off-by: Juhos Gabor <juhosg@openwrt.org>
Signed-off-by: Florian Fainelli <florian@openwrt.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:07 -07:00
Tomas Hallenberg 76d800a5b6 gpio: timbgpio: use a copy of the IER register to avoid it being trashed
Some versions of the hardware can trash the IER register if simultaneous
interrupts occur.  This patch works around it by using a local copy of the
register and restoring it after every interrupt.

Signed-off-by: Tomas Hallenberg <tomas.hallenberg@pelagicore.com>
Acked-by: Richard Röjfors <richard.rojfors@pelagicore.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:07 -07:00
Anton Vorontsov 09cd9527d6 gpiolib: fix HAVE_GPIO_LIB leftovers in asm-generic/gpio.h
commit 7444a72eff ("gpiolib: allow user-selection")
removed HAVE_GPIO_LIB Kconfig symbol, but the header file still uses the
name [to confuse readers wrt #ifdef/#else/#endif location].

The real Kconfig symbol nowadays is CONFIG_GPIOLIB.

Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:06 -07:00
Anton Vorontsov aeec56e331 gpio: add driver for basic memory-mapped GPIO controllers
The basic GPIO controllers may be found in various on-board FPGA and ASIC
solutions that are used to control board's switches, LEDs, chip-selects,
Ethernet/USB PHY power, etc.

These controllers may not provide any means of pin setup
(in/out/open drain).

The driver supports:
- 8/16/32/64 bits registers;
- GPIO controllers with clear/set registers;
- GPIO controllers with a single "data" register;
- Big endian bits/GPIOs ordering (mostly used on PowerPC).

Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com>
Reviewed-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: David Brownell <david-b@pacbell.net>
Cc: Samuel Ortiz <sameo@linux.intel.com>,
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:06 -07:00
Paul Cercueil d0f744c8cb drivers/rtc/rtc-jz4740.c: add alarm function
Add the "alarm" function to the jz4740 RTC.  Interrupts will now be raised
when the "alarm" time is reached.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Cc: Wan ZongShun <mcuos.com@gmail.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Paul Gortmaker <p_gortmaker@yahoo.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:06 -07:00
Lan Chunhe-B25806 f46418c5ca drivers/rtc/rtc-ds3232.c: add alarm function
The DS3232 RTC driver only has the tick function.  Add an alarm function
so the driver is complete.

Signed-off-by: Lan Chunhe-B25806 <b25806@freescale.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Wan ZongShun <mcuos.com@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:06 -07:00
Kukjin Kim 5b3ffddd8d rtc: rtc-s3c: add rtc_valid_tm in s3c_rtc_gettime()
Add "rtc_valid_tm" in s3c_rtc_gettime() as per Wan ZongShun's suggestion.

Suggested-by: Wan ZongShun <mcuos.com@gmail.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Cc: Ben Dooks <ben-linux@fluff.org>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:06 -07:00
Changhwan Youn e1df962e6c rtc: rtc-s3c: fix RTC initialization method
Change RTC initialization method in probe().  The 'rtc_valid_tm(tm)' can
check whether RTC BCD is valid or not.  And change the method of checking
because the previous method cannot validate RTC BCD registers properly.

Signed-off-by: Changhwan Youn <chaos.youn@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Cc: Ben Dooks <ben-linux@fluff.org>
Cc: Wan ZongShun <mcuos.com@gmail.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:06 -07:00
Kukjin Kim 30ffc40cf5 rtc: rtc-s3c: Fix debug message format on RTC
Fix debug message format.

Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Acked-by: Ben Dooks <ben-linux@fluff.org>
Cc: Wan ZongShun <mcuos.com@gmail.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:06 -07:00
Changhwan Youn e6eb524e6e rtc: rtc-s3c: fix on support RTC Alarm
The alarm_irq_enable function should be implemented to support RTC alarm.
And fix tabs instead of white space around the proc field.

Signed-off-by: Changhwan Youn <chaos.youn@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Acked-by: Ben Dooks <ben-linux@fluff.org>
Cc: Wan ZongShun <mcuos.com@gmail.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:06 -07:00
Changhwan Youn dd061d1abe rtc: rtc-s3c: fix setting missing field of getalarm
Current s3c_rtc_getalarm() sets missing field of alarm time with 0xff.
But this value should be -1 according to drivers/rtc/interface.c.

Signed-off-by: Changhwan Youn <chaos.youn@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Acked-by: Ben Dooks <ben-linux@fluff.org>
Cc: Wan ZongShun <mcuos.com@gmail.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:06 -07:00
Changhwan Youn f61ae6711d rtc: rtc-s3c: fix access unit from byte to word on RTCCON
S3C2410_RTCCON of TYPE_S3C64XX RTC should be read/written by readw and
writew, because TYPE_S3C64XX RTC uses bit 8 and 9.  And TYPE_S3C2410 RTC
also can access it by readw and writew.

[atul.dahiya@samsung.com: tested on smdk2416]
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Changhwan Youn <chaos.youn@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Tested-by: Atul Dahiya <atul.dahiya@samsung.com>
Cc: Ben Dooks <ben-linux@fluff.org>
Cc: Wan ZongShun <mcuos.com@gmail.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-27 18:03:06 -07:00