20 Nov, 2008
1 commit
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A problem was found while reviewing the code after Bugzilla bug
http://bugzilla.kernel.org/show_bug.cgi?id=11796.In ipc_addid(), the newly allocated ipc structure is inserted into the
ipcs tree (i.e made visible to readers) without locking it. This is not
correct since its initialization continues after it has been inserted in
the tree.This patch moves the ipc structure lock initialization + locking before
the actual insertion.Signed-off-by: Nadia Derbey
Reported-by: Clement Calmels
Cc: Manfred Spraul
Cc: [2.6.27.x]
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
21 Oct, 2008
1 commit
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Signed-off-by: Al Viro
20 Oct, 2008
2 commits
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Increase the range of various posix message queue limits.
Posix gives the message queue user the ability to 'trade off' the maximum
size of messages with the number of possible messages that can be 'in
flight'. Linux currently makes this trade off more restrictive than it
needs to be.In particular, the maximum message size today can be made no smaller than
8192. This greatly restricts those applications that would like to have
the ability to post large numbers of very small messages.So this task lowers the limit that the maximum message size can be set to,
from 8192 to 128. It also lowers the limit that the maximum #number of
messages in flight can be set to, from 10 to 1.With these changes the message queue user can make better trade offs
between #messages and message size, in order to get everything to fit
within the setrlimit(RLIMIT_MSGQUEUE) limit for that particular user.This patch also applies the values in
/proc/sys/fs/mqueue/msg_max
/proc/sys/fs/mqueue/msgsize_maxas the defaults for the max #messages allowed and the max message size
allowed, respectively, for those applications that do not supply these.
Previously, the defaults were hardwired to 10 and 8192, respectively.[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Joe Korty
Cc: Al Viro
Cc: Manfred Spraul
Cc: Nadia Derbey
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Shmem segments locked into memory via shmctl(SHM_LOCKED) should not be
kept on the normal LRU, since scanning them is a waste of time and might
throw off kswapd's balancing algorithms. Place them on the unevictable
LRU list instead.Use the AS_UNEVICTABLE flag to mark address_space of SHM_LOCKed shared
memory regions as unevictable. Then these pages will be culled off the
normal LRU lists during vmscan.Add new wrapper function to clear the mapping's unevictable state when/if
shared memory segment is munlocked.Add 'scan_mapping_unevictable_page()' to mm/vmscan.c to scan all pages in
the shmem segment's mapping [struct address_space] for evictability now
that they're no longer locked. If so, move them to the appropriate zone
lru list.Changes depend on [CONFIG_]UNEVICTABLE_LRU.
[kosaki.motohiro@jp.fujitsu.com: revert shm change]
Signed-off-by: Lee Schermerhorn
Signed-off-by: Rik van Riel
Signed-off-by: Kosaki Motohiro
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
17 Oct, 2008
2 commits
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Signed-off-by: Adrian Bunk
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
name and nlen parameters passed to ->strategy hook are unused, remove
them. In general ->strategy hook should know what it's doing, and don't
do something tricky for which, say, pointer to original userspace array
may be needed (name).Signed-off-by: Alexey Dobriyan
Acked-by: David S. Miller [ networking bits ]
Cc: Ralf Baechle
Cc: David Howells
Cc: Matt Mackall
Cc: "Eric W. Biederman"
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
27 Jul, 2008
2 commits
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Incidentally, the name that gives hundreds of false positives on grep
is not a good idea...Signed-off-by: Al Viro
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Kmem cache passed to constructor is only needed for constructors that are
themselves multiplexeres. Nobody uses this "feature", nor does anybody uses
passed kmem cache in non-trivial way, so pass only pointer to object.Non-trivial places are:
arch/powerpc/mm/init_64.c
arch/powerpc/mm/hugetlbpage.cThis is flag day, yes.
Signed-off-by: Alexey Dobriyan
Acked-by: Pekka Enberg
Acked-by: Christoph Lameter
Cc: Jon Tollefson
Cc: Nick Piggin
Cc: Matt Mackall
[akpm@linux-foundation.org: fix arch/powerpc/mm/hugetlbpage.c]
[akpm@linux-foundation.org: fix mm/slab.c]
[akpm@linux-foundation.org: fix ubifs]
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
26 Jul, 2008
8 commits
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This patch proposes an alternative to the "magical
positive-versus-negative number trick" Andrew complained about last week
in http://lkml.org/lkml/2008/6/24/418.This had been introduced with the patches that scale msgmni to the amount
of lowmem. With these patches, msgmni has a registered notification
routine that recomputes msgmni value upon memory add/remove or ipc
namespace creation/ removal.When msgmni is changed from user space (i.e. value written to the proc
file), that notification routine is unregistered, and the way to make it
registered back is to write a negative value into the proc file. This is
the "magical positive-versus-negative number trick".To fix this, a new proc file is introduced: /proc/sys/kernel/auto_msgmni.
This file acts as ON/OFF for msgmni automatic recomputing.With this patch, the process is the following:
1) kernel boots in "automatic recomputing mode"
/proc/sys/kernel/msgmni contains the value that has been computed (depends
on lowmem)
/proc/sys/kernel/automatic_msgmni contains "1"2) echo > /proc/sys/kernel/msgmni
. sets msg_ctlmni to
. de-activates automatic recomputing (i.e. if, say, some memory is added
msgmni won't be recomputed anymore)
. /proc/sys/kernel/automatic_msgmni now contains "0"3) echo "0" > /proc/sys/kernel/automatic_msgmni
. de-activates msgmni automatic recomputing
this has the same effect as 2) except that msg_ctlmni's value stays
blocked at its current value)3) echo "1" > /proc/sys/kernel/automatic_msgmni
. recomputes msgmni's value based on the current available memory size
and number of ipc namespaces
. re-activates automatic recomputing for msgmni.Signed-off-by: Nadia Derbey
Cc: Solofo Ramangalahy
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Also this patch kills unneccesary trailing NULL character.
Signed-off-by: Akinobu Mita
Cc: Nadia Derbey
Cc: Manfred Spraul
Cc: Pierre Peiffer
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The attached patch:
- reverses the locking order of ulp->lock and sem_lock:
Previously, it was first ulp->lock, then inside sem_lock.
Now it's the other way around.
- converts the undo structure to rcu.Benefits:
- With the old locking order, IPC_RMID could not kfree the undo structures.
The stale entries remained in the linked lists and were released later.
- The patch fixes a a race in semtimedop(): if both IPC_RMID and a semget() that
recreates exactly the same id happen between find_alloc_undo() and sem_lock,
then semtimedop() would access already kfree'd memory.[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Manfred Spraul
Reviewed-by: Nadia Derbey
Cc: Pierre Peiffer
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
sem_array.sem_pending is a double linked list, the attached patch converts
it to struct list_head.[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Manfred Spraul
Reviewed-by: Nadia Derbey
Cc: Pierre Peiffer
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
sem_queue.sma and sem_queue.id were never used, the attached patch removes
them.Signed-off-by: Manfred Spraul
Reviewed-by: Nadia Derbey
Cc: Pierre Peiffer
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The undo structures contain two linked lists, the attached patch replaces
them with generic struct list_head lists.[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Manfred Spraul
Cc: Nadia Derbey
Cc: Pierre Peiffer
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Remove the ipc_lock_down() routines: they used to call idr_find() locklessly
(given that the ipc ids lock was already held), so they are not needed
anymore.Signed-off-by: Nadia Derbey
Acked-by: "Paul E. McKenney"
Cc: Manfred Spraul
Cc: Jim Houston
Cc: Pierre Peiffer
Acked-by: Rik van Riel
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Call idr_find() locklessly from ipc_lock(), since the idr tree is now RCU
protected.Signed-off-by: Nadia Derbey
Acked-by: "Paul E. McKenney"
Cc: Manfred Spraul
Cc: Jim Houston
Cc: Pierre Peiffer
Acked-by: Rik van Riel
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
25 Jul, 2008
1 commit
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The goal of this patchset is to support multiple hugetlb page sizes. This
is achieved by introducing a new struct hstate structure, which
encapsulates the important hugetlb state and constants (eg. huge page
size, number of huge pages currently allocated, etc).The hstate structure is then passed around the code which requires these
fields, they will do the right thing regardless of the exact hstate they
are operating on.This patch adds the hstate structure, with a single global instance of it
(default_hstate), and does the basic work of converting hugetlb to use the
hstate.Future patches will add more hstate structures to allow for different
hugetlbfs mounts to have different page sizes.[akpm@linux-foundation.org: coding-style fixes]
Acked-by: Adam Litke
Acked-by: Nishanth Aravamudan
Signed-off-by: Andi Kleen
Signed-off-by: Nick Piggin
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
14 Jun, 2008
1 commit
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Conflicts:
drivers/net/smc911x.c
13 Jun, 2008
1 commit
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sysvipc_shm_proc_show() picks between format strings (based on the
expected maximum length of a SHM segment) in a way that prevents gcc from
performing format checks on the seq_printf() parameters. This hid two
format errors - shp->shm_segsz and shp->shm_nattach are both unsigned
long, but were being printed as unsigned int and signed int respectively.
This leads to 32-bit truncation of SHM segment sizes reported in
/proc/sysvipc/shm. (And for nattach, but that's less of a problem for
most users).This patch makes the format string directly visible to gcc's format
specifier checker, and fixes the two broken format specifiers.Signed-off-by: Paul Menage
Cc: Nadia Derbey
Cc: Manfred Spraul
Cc: Pierre Peiffer
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
10 Jun, 2008
1 commit
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Found a silly double assignment of err is do_shmat. Silly, but good to
clean up the useless code.Signed-off-by: Neil Horman
Signed-off-by: Linus Torvalds
07 Jun, 2008
1 commit
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When posting:
[PATCH 1/8] Scaling msgmni to the amount of lowmem
(see http://lkml.org/lkml/2008/2/11/171), I have added a KERN_INFO message
that is output each time msgmni is recomputed.In http://lkml.org/lkml/2008/4/29/575 Tony Luck complained that this
message references an ipc namespace address that is useless.I first thought of using an audit_log instead of a printk, as suggested by
Serge Hallyn. But unfortunately, we do not have any other information
than the namespace address to provide here too. So I chose to move the
message and output it only at boot time, removing the reference to the
namespace.Signed-off-by: Nadia Derbey
Cc: Pierre Peiffer
Cc: Manfred Spraul
Acked-by: Tony Luck
Cc: "Serge E. Hallyn"
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
06 Jun, 2008
1 commit
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Signed-off-by: Denis V. Lunev
Signed-off-by: David S. Miller
04 May, 2008
1 commit
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A very small cleanup for mq_open.
We do not have to call set_close_on_exit if we create the file
descriptor right away with the flag set. We have a function for this
now. The resulting code is smaller and a tiny bit faster.Signed-off-by: Ulrich Drepper
Signed-off-by: Linus Torvalds
29 Apr, 2008
17 commits
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Use proc_create_data() to make sure that ->proc_fops and ->data be setup
before gluing PDE to main tree.Signed-off-by: Denis V. Lunev
Cc: Alexey Dobriyan
Cc: "Eric W. Biederman"
Cc: Nadia Derbey
Cc: Pierre Peiffer
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
sys_unshare(CLONE_NEWIPC) doesn't handle the undo lists properly, this can
cause a kernel memory corruption. CLONE_NEWIPC must detach from the existing
undo lists.Fix, part 1: add support for sys_unshare(CLONE_SYSVSEM)
The original reason to not support it was the potential (inevitable?)
confusion due to the fact that sys_unshare(CLONE_SYSVSEM) has the
inverse meaning of clone(CLONE_SYSVSEM).Our two most reasonable options then appear to be (1) fully support
CLONE_SYSVSEM, or (2) continue to refuse explicit CLONE_SYSVSEM,
but always do it anyway on unshare(CLONE_SYSVSEM). This patch does
(1).Changelog:
Apr 16: SEH: switch to Manfred's alternative patch which
removes the unshare_semundo() function which
always refused CLONE_SYSVSEM.Signed-off-by: Manfred Spraul
Signed-off-by: Serge E. Hallyn
Acked-by: "Eric W. Biederman"
Cc: Pavel Emelyanov
Cc: Michael Kerrisk
Cc: Pierre Peiffer
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Add definitions of USHORT_MAX and others into kernel. ipc uses it and slub
implementation might also use it.[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Zhang Yanmin
Reviewed-by: Christoph Lameter
Cc: Nadia Derbey
Cc: "Pierre Peiffer"
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
semctl_down(), msgctl_down() and shmctl_down() are used to handle the same set
of commands for each kind of IPC. They all start to do the same job (they
retrieve the ipc and do some permission checks) before handling the commands
on their own.This patch proposes to consolidate this by moving these same pieces of code
into one common function called ipcctl_pre_down().It simplifies a little these xxxctl_down() functions and increases a little
the maintainability.Signed-off-by: Pierre Peiffer
Acked-by: Serge Hallyn
Cc: Nadia Derbey
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The IPC_SET command performs the same permission setting for all IPCs. This
patch introduces a common ipc_update_perm() function to update these
permissions and makes use of it for all IPCs.Signed-off-by: Pierre Peiffer
Acked-by: Serge Hallyn
Cc: Nadia Derbey
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
All IPCs make use of an intermetiate *_setbuf structure to handle the IPC_SET
command. This is not really needed and, moreover, it complicates a little bit
the code.This patch gets rid of the use of it and uses directly the semid64_ds/
msgid64_ds/shmid64_ds structure.In addition of removing one struture declaration, it also simplifies and
improves a little bit the common 64-bits path.Signed-off-by: Pierre Peiffer
Acked-by: Serge Hallyn
Cc: Nadia Derbey
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
semctl_down() takes one unused parameter: semnum. This patch proposes to get
rid of it.Signed-off-by: Pierre Peiffer
Acked-by: Serge Hallyn
Cc: Nadia Derbey
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
semctl_down is called with the rwmutex (the one which protects the list of
ipcs) taken in write mode.This patch moves this rwmutex taken in write-mode inside semctl_down.
This has the advantages of reducing a little bit the window during which this
rwmutex is taken, clarifying sys_semctl, and finally of having a coherent
behaviour with [shm|msg]ctl_downSigned-off-by: Pierre Peiffer
Acked-by: Serge Hallyn
Cc: Nadia Derbey
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Currently, sys_msgctl is not easy to read.
This patch tries to improve that by introducing the msgctl_down function to
handle all commands requiring the rwmutex to be taken in write mode (ie
IPC_SET and IPC_RMID for now). It is the equivalent function of semctl_down
for message queues.This greatly changes the readability of sys_msgctl and also harmonizes the way
these commands are handled among all IPCs.Signed-off-by: Pierre Peiffer
Acked-by: Serge Hallyn
Cc: Nadia Derbey
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Currently, the way the different commands are handled in sys_shmctl introduces
some duplicated code.This patch introduces the shmctl_down function to handle all the commands
requiring the rwmutex to be taken in write mode (ie IPC_SET and IPC_RMID for
now). It is the equivalent function of semctl_down for shared memory.This removes some duplicated code for handling these both commands and
harmonizes the way they are handled among all IPCs.Signed-off-by: Pierre Peiffer
Acked-by: Serge Hallyn
Cc: Nadia Derbey
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Trivial patch which adds some small locking functions and makes use of them to
factorize some part of the code and to make it cleaner.Signed-off-by: Pierre Peiffer
Acked-by: Serge Hallyn
Cc: Nadia Derbey
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The enhancement as asked for by Yasunori: if msgmni is set to a negative
value, register it back into the ipcns notifier chain.A new interface has been added to the notification mechanism:
notifier_chain_cond_register() registers a notifier block only if not already
registered. With that new interface we avoid taking care of the states
changes in procfs.Signed-off-by: Nadia Derbey
Cc: Yasunori Goto
Cc: Matt Helsley
Cc: Mingming Cao
Cc: Pierre Peiffer
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Make msgmni not recomputed anymore upon ipc namespace creation / removal or
memory add/remove, as soon as it has been set from userland.As soon as msgmni is explicitly set via procfs or sysctl(), the associated
callback routine is unregistered from the ipc namespace notifier chain.Signed-off-by: Nadia Derbey
Cc: Yasunori Goto
Cc: Matt Helsley
Cc: Mingming Cao
Cc: Pierre Peiffer
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Introduce a notification mechanism that aims at recomputing msgmni each time
an ipc namespace is created or removed.The ipc namespace notifier chain already defined for memory hotplug management
is used for that purpose too.Each time a new ipc namespace is allocated or an existing ipc namespace is
removed, the ipcns notifier chain is notified. The callback routine for each
registered ipc namespace is then activated in order to recompute msgmni for
that namespace.Signed-off-by: Nadia Derbey
Cc: Yasunori Goto
Cc: Matt Helsley
Cc: Mingming Cao
Cc: Pierre Peiffer
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Make the memory hotplug chain's mutex held for a shorter time: when memory is
offlined or onlined a work item is added to the global workqueue. When the
work item is run, it notifies the ipcns notifier chain with the
IPCNS_MEMCHANGED event.Signed-off-by: Nadia Derbey
Cc: Yasunori Goto
Cc: Matt Helsley
Cc: Mingming Cao
Cc: Pierre Peiffer
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Introduce the registration of a callback routine that recomputes msg_ctlmni
upon memory add / remove.A single notifier block is registered in the hotplug memory chain for all the
ipc namespaces.Since the ipc namespaces are not linked together, they have their own
notification chain: one notifier_block is defined per ipc namespace.Each time an ipc namespace is created (removed) it registers (unregisters) its
notifier block in (from) the ipcns chain. The callback routine registered in
the memory chain invokes the ipcns notifier chain with the IPCNS_LOWMEM event.
Each callback routine registered in the ipcns namespace, in turn, recomputes
msgmni for the owning namespace.Signed-off-by: Nadia Derbey
Cc: Yasunori Goto
Cc: Matt Helsley
Cc: Mingming Cao
Cc: Pierre Peiffer
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Since all the namespaces see the same amount of memory (the total one) this
patch introduces a new variable that counts the ipc namespaces and divides
msg_ctlmni by this counter.Signed-off-by: Nadia Derbey
Cc: Yasunori Goto
Cc: Matt Helsley
Cc: Mingming Cao
Cc: Pierre Peiffer
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
