nr_mapped is important because it allows a determination of how many pages of
a zone are not mapped, which would allow a more efficient means of determining
when we need to reclaim memory in a zone.
We take the nr_mapped field out of the page state structure and define a new
per zone counter named NR_FILE_MAPPED (the anonymous pages will be split off
from NR_MAPPED in the next patch).
We replace the use of nr_mapped in various kernel locations. This avoids the
looping over all processors in try_to_free_pages(), writeback, reclaim (swap +
zone reclaim).
[akpm@osdl.org: bugfix]
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Per zone counter infrastructure
The counters that we currently have for the VM are split per processor. The
processor however has not much to do with the zone these pages belong to. We
cannot tell f.e. how many ZONE_DMA pages are dirty.
So we are blind to potentially inbalances in the usage of memory in various
zones. F.e. in a NUMA system we cannot tell how many pages are dirty on a
particular node. If we knew then we could put measures into the VM to balance
the use of memory between different zones and different nodes in a NUMA
system. For example it would be possible to limit the dirty pages per node so
that fast local memory is kept available even if a process is dirtying huge
amounts of pages.
Another example is zone reclaim. We do not know how many unmapped pages exist
per zone. So we just have to try to reclaim. If it is not working then we
pause and try again later. It would be better if we knew when it makes sense
to reclaim unmapped pages from a zone. This patchset allows the determination
of the number of unmapped pages per zone. We can remove the zone reclaim
interval with the counters introduced here.
Futhermore the ability to have various usage statistics available will allow
the development of new NUMA balancing algorithms that may be able to improve
the decision making in the scheduler of when to move a process to another node
and hopefully will also enable automatic page migration through a user space
program that can analyse the memory load distribution and then rebalance
memory use in order to increase performance.
The counter framework here implements differential counters for each processor
in struct zone. The differential counters are consolidated when a threshold
is exceeded (like done in the current implementation for nr_pageache), when
slab reaping occurs or when a consolidation function is called.
Consolidation uses atomic operations and accumulates counters per zone in the
zone structure and also globally in the vm_stat array. VM functions can
access the counts by simply indexing a global or zone specific array.
The arrangement of counters in an array also simplifies processing when output
has to be generated for /proc/*.
Counters can be updated by calling inc/dec_zone_page_state or
_inc/dec_zone_page_state analogous to *_page_state. The second group of
functions can be called if it is known that interrupts are disabled.
Special optimized increment and decrement functions are provided. These can
avoid certain checks and use increment or decrement instructions that an
architecture may provide.
We also add a new CONFIG_DMA_IS_NORMAL that signifies that an architecture can
do DMA to all memory and therefore ZONE_NORMAL will not be populated. This is
only currently set for IA64 SGI SN2 and currently only affects
node_page_state(). In the best case node_page_state can be reduced to
retrieving a single counter for the one zone on the node.
[akpm@osdl.org: cleanups]
[akpm@osdl.org: export vm_stat[] for filesystems]
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
register_cpu_notifier() cannot do anything in a module, in a
!CONFIG_HOTPLUG_CPU kernel.
Cc: Chandra Seetharaman <sekharan@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
skb_release_data() no longer has any users in other files.
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Happily, life is much simpler on 32-bit sparc systems.
The "intr" property, preferred over the "interrupts"
property is used-as. Some minor translations of this
value happen on sun4d systems.
The stage is now set to rewrite the sparc serial driver
probing to use the of_driver framework, and then to convert
all SBUS, EBUS, and ISA drivers in-kind so that we can nuke
all those special bus frameworks.
Signed-off-by: David S. Miller <davem@davemloft.net>
Do IRQ determination generically by parsing the PROM properties,
and using IRQ controller drivers for final resolution.
One immediate positive effect is that all of the IRQ frobbing
in the EBUS, ISA, and PCI controller layers has been eliminated.
We just look up the of_device and use the properly computed
value.
The PCI controller irq_build() routines are gone and no longer
used. Unfortunately sbus_build_irq() has to remain as there is
a direct reference to this in the sunzilog driver. That can be
killed off once the sparc32 side of this is written and the
sunzilog driver is transformed into an "of" bus driver.
Signed-off-by: David S. Miller <davem@davemloft.net>
This needs to be a unique interrupt source because we do
not have a register or similar to poll to make sure the
IRQ is really for us. We do not have any dev_id to pass
in anyways, and the generic IRQ layer is now enforcing
that when SA_SHIRQ is specified, dev_id must be non-NULL.
Signed-off-by: David S. Miller <davem@davemloft.net>
On sparc64 we don't need to do this because the resource
values are large enough to encode the full physical address.
Signed-off-by: David S. Miller <davem@davemloft.net>
The idea is to fully construct the device register and
interrupt values into these of_device objects, and convert
all of SBUS, EBUS, ISA drivers to use this new stuff.
Much ideas and code taken from Ben H.'s powerpc work.
Signed-off-by: David S. Miller <davem@davemloft.net>
Totally unused.
We need to traverse the list of global IRQ translaters,
so storing it in the per-bus structures was useless.
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch removes unused system type name.
DDB5074 and DDB5476 were already removed.
Signed-off-by: Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This fixes a resource collision of RAM and I/O memory on systems that
use the physical address space multiple times.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
o Fix the build error Wind River PPMC board caused by the change of
plat_setup hook interface.
o Rewrite first level interrupt dispatch code to C.
Signed-off-by: Rongkai.Zhan <rongkai.zhan@windriver.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Several KConfig files had 'similarity' and 'independent' spelled incorrectly...
Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This is a fixed up and cleaned up replacement for genirq-msi-fixes.patch,
which should solve the i386 4KSTACKS problem. I also added Ben's idea of
pushing the __do_IRQ() check into generic_handle_irq().
I booted this with MSI enabled, but i only have MSI devices, not MSI-X
devices. I'd still expect MSI-X to work now.
irqchip migration helper: call __do_IRQ() if a descriptor is attached to an
irqtype-style controller. This also fixes MSI-X IRQ handling on i386 and
x86_64.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Roland Dreier <rolandd@cisco.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Add ->retrigger() irq op to consolidate hw_irq_resend() implementations.
(Most architectures had it defined to NOP anyway.)
NOTE: ia64 needs testing. i386 and x86_64 tested.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Christoph Lameter