This patch fixes a regression in 2.6.14 against 2.6.13 that causes an
imbalance in memory allocation during bootup.
The slab allocator in 2.6.13 is not numa aware and simply calls
alloc_pages(). This means that memory policies may control the behavior of
alloc_pages(). During bootup the memory policy is set to MPOL_INTERLEAVE
resulting in the spreading out of allocations during bootup over all
available nodes. The slab allocator in 2.6.13 has only a single list of
slab pages. As a result the per cpu slab cache and the spinlock controlled
page lists may contain slab entries from off node memory. The slab
allocator in 2.6.13 makes no effort to discern the locality of an entry on
its lists.
The NUMA aware slab allocator in 2.6.14 controls locality of the slab pages
explicitly by calling alloc_pages_node(). The NUMA slab allocator manages
slab entries by having lists of available slab pages for each node. The
per cpu slab cache can only contain slab entries associated with the node
local to the processor. This guarantees that the default allocation mode
of the slab allocator always assigns local memory if available.
Setting MPOL_INTERLEAVE as a default policy during bootup has no effect
anymore. In 2.6.14 all node unspecific slab allocations are performed on
the boot processor. This means that most of key data structures are
allocated on one node. Most processors will have to refer to these
structures making the boot node a potential bottleneck. This may reduce
performance and cause unnecessary memory pressure on the boot node.
This patch implements NUMA policies in the slab layer. There is the need
of explicit application of NUMA memory policies by the slab allcator itself
since the NUMA slab allocator does no longer let the page_allocator control
locality.
The check for policies is made directly at the beginning of __cache_alloc
using current->mempolicy. The memory policy is already frequently checked
by the page allocator (alloc_page_vma() and alloc_page_current()). So it
is highly likely that the cacheline is present. For MPOL_INTERLEAVE
kmalloc() will spread out each request to one node after another so that an
equal distribution of allocations can be obtained during bootup.
It is not possible to push the policy check to lower layers of the NUMA
slab allocator since the per cpu caches are now only containing slab
entries from the current node. If the policy says that the local node is
not to be preferred or forbidden then there is no point in checking the
slab cache or local list of slab pages. The allocation better be directed
immediately to the lists containing slab entries for the allowed set of
nodes.
This way of applying policy also fixes another strange behavior in 2.6.13.
alloc_pages() is controlled by the memory allocation policy of the current
process. It could therefore be that one process is running with
MPOL_INTERLEAVE and would f.e. obtain a new page following that policy
since no slab entries are in the lists anymore. A page can typically be
used for multiple slab entries but lets say that the current process is
only using one. The other entries are then added to the slab lists. These
are now non local entries in the slab lists despite of the possible
availability of local pages that would provide faster access and increase
the performance of the application.
Another process without MPOL_INTERLEAVE may now run and expect a local slab
entry from kmalloc(). However, there are still these free slab entries
from the off node page obtained from the other process via MPOL_INTERLEAVE
in the cache. The process will then get an off node slab entry although
other slab entries may be available that are local to that process. This
means that the policy if one process may contaminate the locality of the
slab caches for other processes.
This patch in effect insures that a per process policy is followed for the
allocation of slab entries and that there cannot be a memory policy
influence from one process to another. A process with default policy will
always get a local slab entry if one is available. And the process using
memory policies will get its memory arranged as requested. Off-node slab
allocation will require the use of spinlocks and will make the use of per
cpu caches not possible. A process using memory policies to redirect
allocations offnode will have to cope with additional lock overhead in
addition to the latency added by the need to access a remote slab entry.
Changes V1->V2
- Remove #ifdef CONFIG_NUMA by moving forward declaration into
prior #ifdef CONFIG_NUMA section.
- Give the function determining the node number to use a saner
name.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
proc support for zone reclaim
This patch creates a proc entry /proc/sys/vm/zone_reclaim_mode that may be
used to override the automatic determination of the zone reclaim made on
bootup.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Some bits for zone reclaim exists in 2.6.15 but they are not usable. This
patch fixes them up, removes unused code and makes zone reclaim usable.
Zone reclaim allows the reclaiming of pages from a zone if the number of
free pages falls below the watermarks even if other zones still have enough
pages available. Zone reclaim is of particular importance for NUMA
machines. It can be more beneficial to reclaim a page than taking the
performance penalties that come with allocating a page on a remote zone.
Zone reclaim is enabled if the maximum distance to another node is higher
than RECLAIM_DISTANCE, which may be defined by an arch. By default
RECLAIM_DISTANCE is 20. 20 is the distance to another node in the same
component (enclosure or motherboard) on IA64. The meaning of the NUMA
distance information seems to vary by arch.
If zone reclaim is not successful then no further reclaim attempts will
occur for a certain time period (ZONE_RECLAIM_INTERVAL).
This patch was discussed before. See
http://marc.theaimsgroup.com/?l=linux-kernel&m=113519961504207&w=2http://marc.theaimsgroup.com/?l=linux-kernel&m=113408418232531&w=2http://marc.theaimsgroup.com/?l=linux-kernel&m=113389027420032&w=2http://marc.theaimsgroup.com/?l=linux-kernel&m=113380938612205&w=2
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Migration code currently does not take a reference to target page
properly, so between unlocking the pte and trying to take a new
reference to the page with isolate_lru_page, anything could happen to
it.
Fix this by holding the pte lock until we get a chance to elevate the
refcount.
Other small cleanups while we're here.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
On alpha:
In file included from drivers/scsi/sym53c8xx_2/sym_glue.h:59,
from drivers/scsi/sym53c8xx_2/sym_fw.c:40:
include/scsi/scsi_transport_spi.h:57: error: field `dv_mutex' has incomplete type
Cc: James Bottomley <James.Bottomley@steeleye.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
From: Eddie C. Dost <ecd@brainaid.de>
I have the following patch for serial console over the RSC
(remote system controller) on my E250 machine. It basically adds
support for input-device=rsc and output-device=rsc from OBP, and
allows 115200,8,n,1,- serial mode setting.
Signed-off-by: David S. Miller <davem@davemloft.net>
Patch from David Vrabel
PXA27x SSP controller has a few different registers, including SCR (serial clock rate) in SSCR0.
Signed-off-by: David Vrabel <dvrabel@arcom.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
There is a new device which is look like:
Serial controller: Decision Computer International Co. PCCOM2 (rev 02) (prog-if 02 [16550])
0700: 6666:0004 (rev 02) (prog-if 02)
Flags: medium devsel, IRQ 177
Memory at fe000000 (32-bit, non-prefetchable) [size=128]
I/O ports at e880 [size=128]
I/O ports at e400 [size=256]
It has two 16550A, and is not listed in kernel, although the
manufacturer clams that it is supported...
I've created the following patch, it only add the new PCI id and the
card to the repository, it seems to work.
Signed-off-by: Alon Bar-Lev <alon.barlev@gmail.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
sparse can't parse a struct definition in include/asm-powerpc/lppaca.h,
even though gcc can accept it. The form looks like this:
struct __attribute__((whatever)) foo { };
An equivalent that both gcc and sparse can handle is
struct foo { } __attribute__((whatever));
This is the only definition of this type in the tree, and fixing it is
easier than fixing sparse.
Signed-off-by: Bryan O'Sullivan <bos@serpentine.com>
[ Side note: fixing sparse wouldn't be hard, but the "attribute at the
end" version is the canonical one, and the one that makes sense. So
let's just fix the kernel instead. Luc Van Oostenryck already sent
out a sparse patch to the sparse mailing list in case anybody cares.
-- Linus ]
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Added macros for min/default/max link priority in tipc_config.h.
Also renamed TIPC_NUM_LINK_PRI to TIPC_MEDIA_LINK_PRI since that
is a more accurate description of what it is used for.
Signed-off-by: Per Liden <per.liden@ericsson.com>
This patch fixes OMAP clock framework to use clk_enable/disable
instead of clk_use/unuse as specified in include/linux/clk.h.
Instances of clk_use/unuse are renamed to clk_enable/disable,
and references clk_use/unuse are removed.
Signed-off-by: Tony Lindgren <tony@atomide.com>
Some subsystems, such as PPP, can send negative values
here. It just happened to work correctly on 32-bit with
an unsigned value, but on 64-bit this explodes.
Figured out by Paul Mackerras based upon several PPP crash
reports.
Signed-off-by: David S. Miller <davem@davemloft.net>
These definitions ware used for only internal use in kernel <= 2.6.13,
which had not introduced the unified parser of IPv6 extension header yet.
Signed-off-by: Yasuyuki Kozakai <yasuyuki.kozakai@toshiba.co.jp>
Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Procfs always output IPV6 addresses without the colon
characters, and we cannot change that.
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Patch fixes a build problem with CONFIG_X86_VSMP. The vSMP bits probably
gathered some fuzz on its way to mainline, and safe_halt() which was outside
the #endif (CONFIG_X86_VSMP) somehow got inside the !CONFIG_X86_VSMP condition,
hence being undefined and breaking CONFIG_X86_VSMP builds. Patch takes
safe_halt() and halt() macros out of the #endif
Signed-off-by: Ravikiran Thirumalai <kiran@scalex86.org>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Add __meminit to the __init lineup to ensure functions default
to __init when memory hotplug is not enabled. Replace __devinit
with __meminit on functions that were changed when the memory
hotplug code was introduced.
Signed-off-by: Matt Tolentino <matthew.e.tolentino@intel.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Another try at this.
For 32bit follow the 32bit implementation from Ingo -
mappings are growing down from the end of stack now
and vary randomly by 1GB.
Randomized mappings for 64bit just vary the normal mmap break
by 1TB. I didn't bother implementing full flex mmap for 64bit
because it shouldn't be needed there.
Cc: mingo@elte.hu
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This builds on some of the clock framework code to support a simple system
timer interface.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Cc: john stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This adds a relatively simplistic clock framework for sh. The initial goal
behind this is to clean up the arch/sh/kernel/time.c mess and to get the CPU
subtype-specific frequency setting and calculation code moved somewhere more
sensible.
This only deals with the core clocks at the moment, though it's trivial for
other drivers to define their own clocks as desired.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Cc: john stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This introduces a few changes in the way that the I/O routines are defined on
SH, specifically so that things like the iomap API properly wrap through the
machvec for board-specific quirks.
In addition to this, the old p3_ioremap() work is converted to a more generic
__ioremap() that will map through the PMB if it's available, or fall back on
page tables for everything else.
An alpha-like IO_CONCAT is also added so we can start to clean up the
board-specific io.h mess, which will be handled in board update patches..
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This moves the various IRQ controller drivers into a new subdirectory, and
also extends the INTC2 IRQ handler to also deal with SH7760 and SH7780
interrupts, rather than just ST-40.
The old CONFIG_SH_GENERIC has also been removed from the IRQ definitions, as
new ports are expected to be based off of CONFIG_SH_UNKNOWN. Since there are
plenty of incompatible machvecs, CONFIG_SH_GENERIC doesn't make sense anymore.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This adds kexec() support for SH.
Signed-off-by: kogiidena <kogiidena@eggplant.ddo.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Cc: <fastboot@lists.osdl.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This extends the current SH DMA API somewhat to support a proper virtual
channel abstraction, and also works to represent this through the driver model
by giving each DMAC its own platform device.
There's also a few other minor changes to support a few new CPU subtypes, and
make TEI generation for the SH DMAC configurable.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Fix reiserfs compilation as a side effect =)
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: Ian Molton <spyro@f2s.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
arm26 currently has a 256 kB THREAD_SIZE (sic).
Looking at the comment in the code, this seems to be based on a
misunderstanding.
The comment says:
this needs attention (see kernel/fork.c which gets a nice div by zero if
this is lower than 8*32768
kernel/fork.c does:
max_threads = mempages / (8 * THREAD_SIZE / PAGE_SIZE)
Therefore, a division by 0 is impossible for all reasonable cases with
THREAD_SIZE >= PAGE_SIZE.
Since the minimum PAGE_SIZE Linux uses on the arm26 architecture is 16k,
PAGE_SIZE should be sufficient for THREAD_SIZE.
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Ian Molton <spyro@f2s.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Because PAL spec has changed since 2002, you can goto
http://developer.intel.com/design/itanium/manuals/iiasdmanual.htm to
download new SDM, all PAL calls should be invoked with psr.ic=1, and
it's caller's responsibility to handle possible tlb miss.
Ia64_pal_cache_flush was written according to old spec, it is obsolete,
and this patch has ia64_pal_cache_flush conform to new spec.
Signed-off-by Anthony Xu <anthony.xu@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
This patch contains an attempt to properly build hostap.o without
#include'ing C files.
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
The ioctl was renamed from SIOCSIWNAME to SIOCSIWCOMMIT.
Signed-off-by: Pete Zaitcev <zaitcev@redhat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This prevents running out of GSIs on large Unisys ES7000 machines.
Follows i386
Cc: "Protasevich, Natalie" <Natalie.Protasevich@unisys.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This unbreaks recursive kprobes which didn't work anymore
due to an earlier patch which converted the debug entry point
to use an IST.
This also allows nesting of the debug entry point too.
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
