Simplify page cache zeroing of segments of pages through 3 functions
zero_user_segments(page, start1, end1, start2, end2)
Zeros two segments of the page. It takes the position where to
start and end the zeroing which avoids length calculations and
makes code clearer.
zero_user_segment(page, start, end)
Same for a single segment.
zero_user(page, start, length)
Length variant for the case where we know the length.
We remove the zero_user_page macro. Issues:
1. Its a macro. Inline functions are preferable.
2. The KM_USER0 macro is only defined for HIGHMEM.
Having to treat this special case everywhere makes the
code needlessly complex. The parameter for zeroing is always
KM_USER0 except in one single case that we open code.
Avoiding KM_USER0 makes a lot of code not having to be dealing
with the special casing for HIGHMEM anymore. Dealing with
kmap is only necessary for HIGHMEM configurations. In those
configurations we use KM_USER0 like we do for a series of other
functions defined in highmem.h.
Since KM_USER0 is depends on HIGHMEM the existing zero_user_page
function could not be a macro. zero_user_* functions introduced
here can be be inline because that constant is not used when these
functions are called.
Also extract the flushing of the caches to be outside of the kmap.
[akpm@linux-foundation.org: fix nfs and ntfs build]
[akpm@linux-foundation.org: fix ntfs build some more]
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Steven French <sfrench@us.ibm.com>
Cc: Michael Halcrow <mhalcrow@us.ibm.com>
Cc: <linux-ext4@vger.kernel.org>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Anton Altaparmakov <aia21@cantab.net>
Cc: Mark Fasheh <mark.fasheh@oracle.com>
Cc: David Chinner <dgc@sgi.com>
Cc: Michael Halcrow <mhalcrow@us.ibm.com>
Cc: Steven French <sfrench@us.ibm.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'slub-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/christoph/vm:
Explain kmem_cache_cpu fields
SLUB: Do not upset lockdep
SLUB: Fix coding style violations
Add parameter to add_partial to avoid having two functions
SLUB: rename defrag to remote_node_defrag_ratio
Move count_partial before kmem_cache_shrink
SLUB: Fix sysfs refcounting
slub: fix shadowed variable sparse warnings
Add a parameter to add_partial instead of having separate functions. The
parameter allows a more detailed control of where the slab pages is placed in
the partial queues.
If we put slabs back to the front then they are likely immediately used for
allocations. If they are put at the end then we can maximize the time that
the partial slabs spent without being subject to allocations.
When deactivating slab we can put the slabs that had remote objects freed (we
can see that because objects were put on the freelist that requires locks) to
them at the end of the list so that the cachelines of remote processors can
cool down. Slabs that had objects from the local cpu freed to them (objects
exist in the lockless freelist) are put in the front of the list to be reused
ASAP in order to exploit the cache hot state of the local cpu.
Patch seems to slightly improve tbench speed (1-2%).
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The NUMA defrag works by allocating objects from partial slabs on remote
nodes. Rename it to
remote_node_defrag_ratio
to be clear about this.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Move the counting function for objects in partial slabs so that it is placed
before kmem_cache_shrink.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
If CONFIG_SYSFS is set then free the kmem_cache structure when
sysfs tells us its okay.
Otherwise there is the danger (as pointed out by
Al Viro) that sysfs thinks the kobject still exists after
kmem_cache_destroy() removed it.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Reviewed-by: Pekka J Enberg <penberg@cs.helsinki.fi>
Introduce 'len' at outer level:
mm/slub.c:3406:26: warning: symbol 'n' shadows an earlier one
mm/slub.c:3393:6: originally declared here
No need to declare new node:
mm/slub.c:3501:7: warning: symbol 'node' shadows an earlier one
mm/slub.c:3491:6: originally declared here
No need to declare new x:
mm/slub.c:3513:9: warning: symbol 'x' shadows an earlier one
mm/slub.c:3492:6: originally declared here
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Drivers that register a ->fault handler, but do not range-check the
offset argument, must set VM_DONTEXPAND in the vm_flags in order to
prevent an expanding mremap from overflowing the resource.
I've audited the tree and attempted to fix these problems (usually by
adding VM_DONTEXPAND where it is not obvious).
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Frederik Himpe reported an unkillable and un-straceable pan process.
Zero length iovecs can go into an infinite loop in writev, because the
iovec iterator does not always advance over them.
The sequence required to trigger this is not trivial. I think it
requires that a zero-length iovec be followed by a non-zero-length iovec
which causes a pagefault in the atomic usercopy. This causes the writev
code to drop back into single-segment copy mode, which then tries to
copy the 0 bytes of the zero-length iovec; a zero length copy looks like
a failure though, so it loops.
Put a test into iov_iter_advance to catch zero-length iovecs. We could
just put the test in the fallback path, but I feel it is more robust to
skip over zero-length iovecs throughout the code (iovec iterator may be
used in filesystems too, so it should be robust).
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'task_killable' of git://git.kernel.org/pub/scm/linux/kernel/git/willy/misc: (22 commits)
Remove commented-out code copied from NFS
NFS: Switch from intr mount option to TASK_KILLABLE
Add wait_for_completion_killable
Add wait_event_killable
Add schedule_timeout_killable
Use mutex_lock_killable in vfs_readdir
Add mutex_lock_killable
Use lock_page_killable
Add lock_page_killable
Add fatal_signal_pending
Add TASK_WAKEKILL
exit: Use task_is_*
signal: Use task_is_*
sched: Use task_contributes_to_load, TASK_ALL and TASK_NORMAL
ptrace: Use task_is_*
power: Use task_is_*
wait: Use TASK_NORMAL
proc/base.c: Use task_is_*
proc/array.c: Use TASK_REPORT
perfmon: Use task_is_*
...
Fixed up conflicts in NFS/sunrpc manually..
They now look like:
hal-resmgr[13791]: segfault at 3c rip 2b9c8caec182 rsp 7fff1e825d30 error 4 in libacl.so.1.1.0[2b9c8caea000+6000]
This makes it easier to pinpoint bugs to specific libraries.
And printing the offset into a mapping also always allows to find the
correct fault point in a library even with randomized mappings. Previously
there was no way to actually find the correct code address inside
the randomized mapping.
Relies on earlier patch to shorten the printk formats.
They are often now longer than 80 characters, but I think that's worth it.
[includes fix from Eric Dumazet to check d_path error value]
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The break_lock data structure and code for spinlocks is quite nasty.
Not only does it double the size of a spinlock but it changes locking to
a potentially less optimal trylock.
Put all of that under CONFIG_GENERIC_LOCKBREAK, and introduce a
__raw_spin_is_contended that uses the lock data itself to determine whether
there are waiters on the lock, to be used if CONFIG_GENERIC_LOCKBREAK is
not set.
Rename need_lockbreak to spin_needbreak, make it use spin_is_contended to
decouple it from the spinlock implementation, and make it typesafe (rwlocks
do not have any need_lockbreak sites -- why do they even get bloated up
with that break_lock then?).
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Randomize the location of the heap (brk) for i386 and x86_64. The range is
randomized in the range starting at current brk location up to 0x02000000
offset for both architectures. This, together with
pie-executable-randomization.patch and
pie-executable-randomization-fix.patch, should make the address space
randomization on i386 and x86_64 complete.
Arjan says:
This is known to break older versions of some emacs variants, whose dumper
code assumed that the last variable declared in the program is equal to the
start of the dynamically allocated memory region.
(The dumper is the code where emacs effectively dumps core at the end of it's
compilation stage; this coredump is then loaded as the main program during
normal use)
iirc this was 5 years or so; we found this way back when I was at RH and we
first did the security stuff there (including this brk randomization). It
wasn't all variants of emacs, and it got fixed as a result (I vaguely remember
that emacs already had code to deal with it for other archs/oses, just
ifdeffed wrongly).
It's a rare and wrong assumption as a general thing, just on x86 it mostly
happened to be true (but to be honest, it'll break too if gcc does
something fancy or if the linker does a non-standard order). Still its
something we should at least document.
Note 2: afaik it only broke the emacs *build*. I'm not 100% sure about that
(it IS 5 years ago) though.
[ akpm@linux-foundation.org: deuglification ]
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Roland McGrath <roland@redhat.com>
Cc: Jakub Jelinek <jakub@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Move the task_struct members specific to rt scheduling together.
A future optimization could be to put sched_entity and sched_rt_entity
into a union.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
CC: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This patch converts the known per-subsystem mutexes to get_online_cpus
put_online_cpus. It also eliminates the CPU_LOCK_ACQUIRE and
CPU_LOCK_RELEASE hotplug notification events.
Signed-off-by: Gautham R Shenoy <ego@in.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/selinux-2.6:
selinux: make mls_compute_sid always polyinstantiate
security/selinux: constify function pointer tables and fields
security: add a secctx_to_secid() hook
security: call security_file_permission from rw_verify_area
security: remove security_sb_post_mountroot hook
Security: remove security.h include from mm.h
Security: remove security_file_mmap hook sparse-warnings (NULL as 0).
Security: add get, set, and cloning of superblock security information
security/selinux: Add missing "space"
This can be broken down into these major areas:
- Documentation updates (language translations and fixes, as
well as kobject and kset documenatation updates.)
- major kset/kobject/ktype rework and fixes. This cleans up the
kset and kobject and ktype relationship and architecture,
making sense of things now, and good documenation and samples
are provided for others to use. Also the attributes for
kobjects are much easier to handle now. This cleaned up a LOT
of code all through the kernel, making kobjects easier to use
if you want to.
- struct bus_type has been reworked to now handle the lifetime
rules properly, as the kobject is properly dynamic.
- struct driver has also been reworked, and now the lifetime
issues are resolved.
- the block subsystem has been converted to use struct device
now, and not "raw" kobjects. This patch has been in the -mm
tree for over a year now, and finally all the issues are
worked out with it. Older distros now properly work with new
kernels, and no userspace updates are needed at all.
- nozomi driver is added. This has also been in -mm for a long
time, and many people have asked for it to go in. It is now
in good enough shape to do so.
- lots of class_device conversions to use struct device instead.
The tree is almost all cleaned up now, only SCSI and IB is the
remaining code to fix up...
* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-2.6: (196 commits)
Driver core: coding style fixes
Kobject: fix coding style issues in kobject c files
Kobject: fix coding style issues in kobject.h
Driver core: fix coding style issues in device.h
spi: use class iteration api
scsi: use class iteration api
rtc: use class iteration api
power supply : use class iteration api
ieee1394: use class iteration api
Driver Core: add class iteration api
Driver core: Cleanup get_device_parent() in device_add() and device_move()
UIO: constify function pointer tables
Driver Core: constify the name passed to platform_device_register_simple
driver core: fix build with SYSFS=n
sysfs: make SYSFS_DEPRECATED depend on SYSFS
Driver core: use LIST_HEAD instead of call to INIT_LIST_HEAD in __init
kobject: add sample code for how to use ksets/ktypes/kobjects
kobject: add sample code for how to use kobjects in a simple manner.
kobject: update the kobject/kset documentation
kobject: remove old, outdated documentation.
...
If the node we're booting on doesn't have memory, bootstrapping kmalloc()
caches resorts to fallback_alloc() which requires ->nodelists set for all
nodes. Fix that by calling set_up_list3s() for CACHE_CACHE in
kmem_cache_init().
As kmem_getpages() is called with GFP_THISNODE set, this used to work before
because of breakage in 2.6.22 and before with GFP_THISNODE returning pages from
the wrong node if a node had no memory. So it may have worked accidentally and
in an unsafe manner because the pages would have been associated with the wrong
node which could trigger bug ons and locking troubles.
Tested-by: Mel Gorman <mel@csn.ul.ie>
Tested-by: Olaf Hering <olaf@aepfle.de>
Reviewed-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
[ With additional one-liner by Olaf Hering - Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This converts the code to use the new kobject functions, cleaning up the
logic in doing so.
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Christoph Lameter
Oleg Nesterov
Linus Torvalds
root
Pekka Enberg
Harvey Harrison
Nick Piggin
Fengguang Wu
Nick Piggin
Andi Kleen
Jiri Kosina
Paul Mundt
Peter Zijlstra
Gautham R Shenoy
Greg Kroah-Hartman