wimax: fix kconfig interactions with rfkill and input layers
WiMAX can work without RFKILL, but it was missing a check to make sure
RFKILL is not being made a module with wimax compiled into the
kernel. This caused failed builds in s390, where CONFIG_INPUT is
always off.
When RFKILL is enabled, the code uses the input layer to report
hardware switch changes; thus, if RFKILL is enabled, INPUT has to be
too. It also needs to display some message when INPUT is disabled that
explains why WiMAX is not selectable.
(issues found by Randy Dunlap in the linux-next tree).
Signed-off-by: Inaky Perez-Gonzalez <inaky@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
wimax: fix '#ifndef CONFIG_BUG' layout to avoid warning
Reported by Randy Dunlap:
> Also, this warning needs to be fixed:
>
> linux-next-20090106/net/wimax/id-table.c:133: warning: ISO C90
> forbids mixed declarations and code
Move the return on #defined(CONFIG_BUG) below the variable
declarations so it doesn't violate ISO C90.
On wimax_id_table_release() we want to do a debug check if CONFIG_BUG
is enabled. However, we also want the debug code to be always compiled
to ensure there is no bitrot. It will be optimized out by the compiler
when CONFIG_BUG is disabled.
Added a note to the function header stating this.
Signed-off-by: Inaky Perez-Gonzalez <inaky@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
r6040: check PHY status when bringing interface up
This patch makes the driver properly initialize the PHY
status if not correctly set by the bootloader/BIOS.
It prevents some boards to bring up the link on boot.
Signed-off-by: Florian Fainelli <florian@openwrt.org> Signed-off-by: David S. Miller <davem@davemloft.net>
Kumar Gala [Thu, 8 Jan 2009 18:58:38 +0000 (10:58 -0800)]
gianfar: Fixup use of BUS_ID_SIZE
Commit b31a1d8b41513b96e9c7ec2f68c5734cef0b26a4 ("gianfar: Convert
gianfar to an of_platform_driver") went back to using BUS_ID_SIZE
instead of sizeof() as per the larger patch series that will remove
"char bus_id[20]" from struct device.
Signed-off-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: David S. Miller <davem@davemloft.net>
Wu Fengguang [Thu, 8 Jan 2009 18:47:01 +0000 (10:47 -0800)]
dm9601: warn on invalid mac address
Add warnings on invalid mac address to help disclose/debug problems.
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Acked-by: Peter Korsgaard <jacmet@sunsite.dk> Signed-off-by: David S. Miller <davem@davemloft.net>
Wu Fengguang [Tue, 6 Jan 2009 18:52:58 +0000 (18:52 +0000)]
dm9601: tell HW about random generated mac address
Otherwise unicast RX will only work in promisc mode.
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Herbert Xu [Thu, 8 Jan 2009 18:40:57 +0000 (10:40 -0800)]
ipv6: Add GRO support
This patch adds GRO support for IPv6. IPv6 GRO supports extension
headers in the same way as GSO (by using the same infrastructure).
It's also simpler compared to IPv4 since we no longer have to worry
about fragmentation attributes or header checksums.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
Linus Torvalds [Thu, 8 Jan 2009 17:10:16 +0000 (09:10 -0800)]
Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (53 commits)
serial: Add driver for the Cell Network Processor serial port NWP device
powerpc: enable dynamic ftrace
powerpc/cell: Fix the prototype of create_vma_map()
powerpc/mm: Make clear_fixmap() actually work
powerpc/kdump: Use ppc_save_regs() in crash_setup_regs()
powerpc: Export cacheable_memzero as its now used in a driver
powerpc: Fix missing semicolons in mmu_decl.h
powerpc/pasemi: local_irq_save uses an unsigned long
powerpc/cell: Fix some u64 vs. long types
powerpc/cell: Use correct types in beat files
powerpc: Use correct type in prom_init.c
powerpc: Remove unnecessary casts
mtd/ps3vram: Use _PAGE_NO_CACHE in memory ioremap
mtd/ps3vram: Use msleep in waits
mtd/ps3vram: Use proper kernel types
mtd/ps3vram: Cleanup ps3vram driver messages
mtd/ps3vram: Remove ps3vram debug routines
mtd/ps3vram: Add modalias support to the ps3vram driver
mtd/ps3vram: Add ps3vram driver for accessing video RAM as MTD
powerpc: Fix iseries drivers build failure without CONFIG_VIOPATH
...
Coly Li [Thu, 8 Jan 2009 02:09:16 +0000 (18:09 -0800)]
fix similar typos to successfull
When I review ocfs2 code, find there are 2 typos to "successfull". After
doing grep "successfull " in kernel tree, 22 typos found totally -- great
minds always think alike :)
This patch fixes all the similar typos. Thanks for Randy's ack and comments.
Signed-off-by: Coly Li <coyli@suse.de> Acked-by: Randy Dunlap <randy.dunlap@oracle.com> Acked-by: Roland Dreier <rolandd@cisco.com> Cc: Jeremy Kerr <jk@ozlabs.org> Cc: Jeff Garzik <jeff@garzik.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Vlad Yasevich <vladislav.yasevich@hp.com> Cc: Sridhar Samudrala <sri@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Wu Fengguang [Thu, 8 Jan 2009 02:09:10 +0000 (18:09 -0800)]
generic swap(): iphase: rename swap() to swap_byte_order()
In preparation for the introduction of a generic swap() macro.
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> 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>
Wu Fengguang [Thu, 8 Jan 2009 02:09:10 +0000 (18:09 -0800)]
generic swap(): sparc: rename swap() to swap_ulong()
In preparation for the introduction of a generic swap() macro.
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> 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>
Magnus Damm [Thu, 8 Jan 2009 02:09:06 +0000 (18:09 -0800)]
vmcore: remove saved_max_pfn check
Remove the saved_max_pfn check from the /proc/vmcore function
read_from_oldmem(). No need to verify, we should be able to just trust
that "elfcorehdr=" is correctly passed to the crash kernel on the kernel
command line like we do with other parameters.
The read_from_oldmem() function in fs/proc/vmcore.c is quite similar to
read_from_oldmem() in drivers/char/mem.c, but only in the latter it makes
sense to use saved_max_pfn. For oldmem it is used to determine when to
stop reading. For vmcore we already have the elf header info pointing out
the physical memory regions, no need to pass the end-of- old-memory twice.
Removing the saved_max_pfn check from vmcore makes it possible for
architectures to skip oldmem but still support crash dump through vmcore -
without the need for the old saved_max_pfn cruft.
Architectures that want to play safe can do the saved_max_pfn check in
copy_oldmem_page(). Not sure why anyone would want to do that, but that's
even safer than today - the saved_max_pfn check in vmcore removed by this
patch only checks the first page.
Signed-off-by: Magnus Damm <damm@igel.co.jp> Acked-by: Vivek Goyal <vgoyal@redhat.com> Acked-by: Simon Horman <horms@verge.net.au> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This small patchset extendes existing commands with reset, master IO and
status messages. Reset is used to reset the bus for given master device,
master IO command allows to initiate IO against bus itself not selecting
slave device first, which can be used to probe the device for example.
And status messages carry command completion status back to the userspace
(namely very useful to get -ENODEV from when requested device was not
found).
Great thanks to Paul Alfille of OWFS for testing and commands suggestions.
This patch:
Allow starting of IO not against already found slave devices, but against
the bus itself, which can be used for example to probe devices.
[akpm@linux-foundation.org: reindent switch statements] Signed-off-by: Evgeniy Polyakov <zbr@ioremap.net> Cc: Paul Alfille <paul.alfille@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Initiates search (or alarm search) and returns all found devices to
userspace. Found devices are not added into the system (i.e. they are
not attached to family devices or bus masters), it will be done via (if
was not done yet) usual timed searching.
Matthew Garrett [Thu, 8 Jan 2009 02:08:56 +0000 (18:08 -0800)]
misc: add dell-laptop driver
Add a driver for controlling Dell-specific backlight and rfkill interfaces.
This driver makes use of the dcdbas interface to the Dell firmware to
allow the backlight and rfkill interfaces on Dell systems to be driven
through the standardised sysfs interfaces.
Signed-off-by: Matthew Garrett <mjg@redhat.com> Cc: Matt Domsch <Matt_Domsch@dell.com> Cc: Ivo van Doorn <ivdoorn@gmail.com> Cc: Len Brown <lenb@kernel.org> Cc: Richard Purdie <rpurdie@rpsys.net> Cc: Henrique de Moraes Holschuh <hmh@hmh.eng.br> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Matthew Garrett [Thu, 8 Jan 2009 02:08:54 +0000 (18:08 -0800)]
dcdbas: export functionality for use in other drivers
The dcdbas code allows calls to be made into the firmware on Dell systems.
Exporting this to other drivers allows them to implement Dell-specific
functionality in a safe way.
Signed-off-by: Matthew Garrett <mjg@redhat.com> Cc: Matt Domsch <Matt_Domsch@dell.com> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Kees Cook [Thu, 8 Jan 2009 02:08:52 +0000 (18:08 -0800)]
ELF: implement AT_RANDOM for glibc PRNG seeding
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.
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.
If a process registers for asynchronous notification on a POSIX message
queue, it gets a signal and a siginfo_t structure when a message arrives
on the message queue. The si_pid in the siginfo_t structure is set to the
PID of the process that sent the message to the message queue.
The principle is the following:
. when mq_notify(SIGEV_SIGNAL) is called, the caller registers for
notification when a msg arrives. The associated pid structure is stroed into
inode_info->notify_owner. Let's call this process P1.
. when mq_send() is called by say P2, P2 sends a signal to P1 to notify
him about msg arrival.
The way .si_pid is set today is not correct, since it doesn't take into account
the fact that the process that is sending the message might not be in the
same namespace as the notified one.
This patch proposes to set si_pid to the sender's pid into the notify_owner
namespace.
Signed-off-by: Nadia Derbey <Nadia.Derbey@bull.net> Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com> Acked-by: 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: Eric W. Biederman <ebiederm@xmission.com> 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>
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>
Li Zefan [Thu, 8 Jan 2009 02:08:45 +0000 (18:08 -0800)]
cpuset: remove remaining pointers to cpumask_t
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>
Li Zefan [Thu, 8 Jan 2009 02:08:44 +0000 (18:08 -0800)]
cpuset: convert cpuset->cpus_allowed to cpumask_var_t
Impact: use new cpumask API
This patch mainly does the following things:
- change cs->cpus_allowed from cpumask_t to cpumask_var_t
- call alloc_bootmem_cpumask_var() for top_cpuset in cpuset_init_early()
- call alloc_cpumask_var() for other cpusets
- replace cpus_xxx() to cpumask_xxx()
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>
Li Zefan [Thu, 8 Jan 2009 02:08:43 +0000 (18:08 -0800)]
cpuset: don't allocate trial cpuset on stack
Impact: cleanups, reduce stack usage
This patch prepares for the next patch. When we convert
cpuset.cpus_allowed to cpumask_var_t, (trialcs = *cs) no longer works.
Another result of this patch is reducing stack usage of trialcs.
sizeof(*cs) can be as large as 148 bytes on x86_64, so it's really not
good to have it on stack.
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>
Miao Xie [Thu, 8 Jan 2009 02:08:40 +0000 (18:08 -0800)]
cpusets: set task's cpu_allowed to cpu_possible_map when attaching it into top cpuset
I found a bug on my dual-cpu box. I created a sub cpuset in top cpuset
and assign 1 to its cpus. And then we attach some tasks into this sub
cpuset. After this, we offline CPU1. Now, the tasks in this new cpuset
are moved into top cpuset automatically because there is no cpu in sub
cpuset. Then we online CPU1, we find all the tasks which doesn't belong
to top cpuset originally just run on CPU0.
We fix this bug by setting task's cpu_allowed to cpu_possible_map when
attaching it into top cpuset. This method needn't modify the current
behavior of cpusets on CPU hotplug, and all of tasks in top cpuset use
cpu_possible_map to initialize their cpu_allowed.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.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>
Paul Menage [Thu, 8 Jan 2009 02:08:38 +0000 (18:08 -0800)]
cgroups: add css_tryget()
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>
Paul Menage [Thu, 8 Jan 2009 02:08:37 +0000 (18:08 -0800)]
cgroups: use hierarchy_mutex in memory controller
Update the memory controller to use its hierarchy_mutex rather than
calling cgroup_lock() to protected against cgroup_mkdir()/cgroup_rmdir()
from occurring in its 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>
Paul Menage [Thu, 8 Jan 2009 02:08:36 +0000 (18:08 -0800)]
cgroups: add a per-subsystem hierarchy_mutex
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.
Now, a page can be deleted from SwapCache while do_swap_page().
memcg-fix-swap-accounting-leak-v3.patch handles that, but, LRU handling is
still broken. (above behavior broke assumption of memcg-synchronized-lru
patch.)
This patch is a fix for LRU handling (especially for per-zone counters).
At charging SwapCache,
- Remove page_cgroup from LRU if it's not used.
- Add page cgroup to LRU if it's not linked to.
Reported-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Balbir Singh <balbir@in.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>
css_tryget() newly is added and we can know css is alive or not and get
refcnt of css in very safe way. ("alive" here means "rmdir/destroy" is
not called.)
This patch replaces css_get() to css_tryget(), where I cannot explain
why css_get() is safe. And removes memcg->obsolete flag.
1. Fix double-free BUG in error route of mem_cgroup_create().
mem_cgroup_free() itself frees per-zone-info.
2. Making refcnt of memcg simple.
Add 1 refcnt at creation and call free when refcnt goes down to 0.
Now, memcg has hooks to swap-out operation and checks SwapCache is really
unused or not. That check depends on contents of struct page. I.e. If
PageAnon(page) && page_mapped(page), the page is recoginized as
still-in-use.
Now, reuse_swap_page() calles delete_from_swap_cache() before establishment
of any rmap. Then, in followinig sequence
(Page fault with WRITE)
try_charge() (charge += PAGESIZE)
commit_charge() (Check page_cgroup is used or not..)
reuse_swap_page()
-> delete_from_swapcache()
-> mem_cgroup_uncharge_swapcache() (charge -= PAGESIZE)
......
New charge is uncharged soon....
To avoid this, move commit_charge() after page_mapcount() goes up to 1.
By this,
try_charge() (usage += PAGESIZE)
reuse_swap_page() (may usage -= PAGESIZE if PCG_USED is set)
commit_charge() (If page_cgroup is not marked as PCG_USED,
add new charge.)
Accounting will be correct.
memcg: change try_to_free_pages to hierarchical_reclaim
mem_cgroup_hierarchicl_reclaim() works properly even when !use_hierarchy
now (by memcg-hierarchy-avoid-unnecessary-reclaim.patch), so, instead of
try_to_free_mem_cgroup_pages(), it should be used in many cases.
The only exception is force_empty. The group has no children in this
case.
memcg: avoid deadlock caused by race between oom and cpuset_attach
mpol_rebind_mm(), which can be called from cpuset_attach(), does
down_write(mm->mmap_sem). This means down_write(mm->mmap_sem) can be
called under cgroup_mutex.
OTOH, page fault path does down_read(mm->mmap_sem) and calls
mem_cgroup_try_charge_xxx(), which may eventually calls
mem_cgroup_out_of_memory(). And mem_cgroup_out_of_memory() calls
cgroup_lock(). This means cgroup_lock() can be called under
down_read(mm->mmap_sem).
If those two paths race, deadlock can happen.
This patch avoid this deadlock by:
- remove cgroup_lock() from mem_cgroup_out_of_memory().
- define new mutex (memcg_tasklist) and serialize mem_cgroup_move_task()
(->attach handler of memory cgroup) and mem_cgroup_out_of_memory.
I think triggering OOM at mem_cgroup_prepare_migration would be just a bit
overkill. Returning -ENOMEM would be enough for
mem_cgroup_prepare_migration. The caller would handle the case anyway.
Show "real" limit of memcg. This helps my debugging and maybe useful for
users.
While testing hierarchy like this
mount -t cgroup none /cgroup -t memory
mkdir /cgroup/A
set use_hierarchy==1 to "A"
mkdir /cgroup/A/01
mkdir /cgroup/A/01/02
mkdir /cgroup/A/01/03
mkdir /cgroup/A/01/03/04
mkdir /cgroup/A/08
mkdir /cgroup/A/08/01
....
and set each own limit to them, "real" limit of each memcg is unclear.
This patch shows real limit by checking all ancestors.
Changelog: (v1) -> (v2)
- remove "if" and use "min(a,b)"
KOSAKI Motohiro [Thu, 8 Jan 2009 02:08:25 +0000 (18:08 -0800)]
memcg: fix calculation of active_ratio
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.
KOSAKI Motohiro [Thu, 8 Jan 2009 02:08:23 +0000 (18:08 -0800)]
memcg: protect prev_priority
Currently, mem_cgroup doesn't have own lock and almost its member doesn't
need. (e.g. mem_cgroup->info is protected by zone lock, mem_cgroup->stat
is per cpu variable)
However, there is one explict exception. mem_cgroup->prev_priorit need
lock, but doesn't protect. Luckly, this is NOT bug because prev_priority
isn't used for current reclaim code.
However, we plan to use prev_priority future again. Therefore, fixing is
better.
In addition, we plan to reuse this lock for another member. Then
"reclaim_param_lock" name is better than "prev_priority_lock".
KOSAKI Motohiro [Thu, 8 Jan 2009 02:08:18 +0000 (18:08 -0800)]
memcg: add inactive_anon_is_low()
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.
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.
KOSAKI Motohiro [Thu, 8 Jan 2009 02:08:17 +0000 (18:08 -0800)]
mm: make get_scan_ratio() safe for memcg
Currently, get_scan_ratio() always calculate the balancing value for
global reclaim and memcg reclaim doesn't use it. Therefore it doesn't
have scan_global_lru() condition.
However, we plan to expand get_scan_ratio() to be usable for memcg too,
latter. Then, The dependency code of global reclaim in the
get_scan_ratio() insert into scan_global_lru() condision explictly.
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.
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.
Balbir Singh [Thu, 8 Jan 2009 02:08:07 +0000 (18:08 -0800)]
memcg: memory cgroup hierarchy feature selector
Don't enable multiple hierarchy support by default. This patch introduces
a features element that can be set to enable the nested depth hierarchy
feature. This feature can only be enabled when the cgroup for which the
feature this is enabled, has no children.
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>
Balbir Singh [Thu, 8 Jan 2009 02:08:06 +0000 (18:08 -0800)]
memcg: memory cgroup hierarchical reclaim
This patch introduces hierarchical reclaim. When an ancestor goes over
its limit, the charging routine points to the parent that is above its
limit. The reclaim process then starts from the last scanned child of the
ancestor and reclaims until the ancestor goes below its limit.
[akpm@linux-foundation.org: coding-style fixes]
[d-nishimura@mtf.biglobe.ne.jp: mem_cgroup_from_res_counter should handle both mem->res and mem->memsw] 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: 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>
Balbir Singh [Thu, 8 Jan 2009 02:08:05 +0000 (18:08 -0800)]
memcg: memory cgroup resource counters for hierarchy
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>
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.
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>
projects / linux-2.6-omap-h63xx.git / log