linux.git/mm/vmstat.c, branch v2.6.30

[ARM] Double check memmap is actually valid with a memmap has unexpected holes V2

2009-05-18T10:22:24+00:00

pfn_valid() is meant to be able to tell if a given PFN has valid memmap
associated with it or not. In FLATMEM, it is expected that holes always
have valid memmap as long as there is valid PFNs either side of the hole.
In SPARSEMEM, it is assumed that a valid section has a memmap for the
entire section.

However, ARM and maybe other embedded architectures in the future free
memmap backing holes to save memory on the assumption the memmap is never
used. The page_zone linkages are then broken even though pfn_valid()
returns true. A walker of the full memmap must then do this additional
check to ensure the memmap they are looking at is sane by making sure the
zone and PFN linkages are still valid. This is expensive, but walkers of
the full memmap are extremely rare.

This was caught before for FLATMEM and hacked around but it hits again for
SPARSEMEM because the page_zone linkages can look ok where the PFN linkages
are totally screwed. This looks like a hatchet job but the reality is that
any clean solution would end up consumning all the memory saved by punching
these unexpected holes in the memmap. For example, we tried marking the
memmap within the section invalid but the section size exceeds the size of
the hole in most cases so pfn_valid() starts returning false where valid
memmap exists. Shrinking the size of the section would increase memory
consumption offsetting the gains.

This patch identifies when an architecture is punching unexpected holes
in the memmap that the memory model cannot automatically detect and sets
ARCH_HAS_HOLES_MEMORYMODEL. At the moment, this is restricted to EP93xx
which is the model sub-architecture this has been reported on but may expand
later. When set, walkers of the full memmap must call memmap_valid_within()
for each PFN and passing in what it expects the page and zone to be for
that PFN. If it finds the linkages to be broken, it assumes the memmap is
invalid for that PFN.

Signed-off-by: Mel Gorman 
Signed-off-by: Russell King

mm: align vmstat_work's timer

2009-04-03T02:04:48+00:00

Even though vmstat_work is marked deferrable, there are still benefits to
aligning it.  For certain applications we want to keep OS jitter as low as
possible and aligning timers and work so they occur together can reduce
their overall impact.

Signed-off-by: Anton Blanchard 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: introduce for_each_populated_zone() macro

2009-04-01T15:59:11+00:00

Impact: cleanup

In almost cases, for_each_zone() is used with populated_zone().  It's
because almost function doesn't need memoryless node information.
Therefore, for_each_populated_zone() can help to make code simplify.

This patch has no functional change.

[akpm@linux-foundation.org: small cleanup]
Signed-off-by: KOSAKI Motohiro 
Cc: KAMEZAWA Hiroyuki 
Cc: Mel Gorman 
Reviewed-by: Johannes Weiner 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

cpumask: use new cpumask_ functions in core code.

2009-03-30T11:35:16+00:00

Impact: cleanup

Time to clean up remaining laggards using the old cpu_ functions.

Signed-off-by: Rusty Russell 
Cc: Greg Kroah-Hartman 
Cc: Ingo Molnar 
Cc: Trond.Myklebust@netapp.com

cpumask: convert mm/

2008-12-31T23:42:29+00:00

Impact: Use new API

Convert kernel mm functions to use struct cpumask.

We skip include/linux/percpu.h and mm/allocpercpu.c, which are in flux.

Signed-off-by: Rusty Russell 
Signed-off-by: Mike Travis 
Reviewed-by: Christoph Lameter

proc: move /proc/zoneinfo boilerplate to mm/vmstat.c

2008-10-23T13:35:04+00:00

Signed-off-by: Alexey Dobriyan 
Acked-by: Christoph Lameter

proc: move /proc/vmstat boilerplate to mm/vmstat.c

2008-10-23T13:12:51+00:00

Signed-off-by: Alexey Dobriyan 
Acked-by: Christoph Lameter

proc: move /proc/pagetypeinfo boilerplate to mm/vmstat.c

2008-10-23T12:33:29+00:00

Signed-off-by: Alexey Dobriyan

proc: move /proc/buddyinfo boilerplate to mm/vmstat.c

2008-10-23T12:12:04+00:00

Signed-off-by: Alexey Dobriyan

mlock: count attempts to free mlocked page

2008-10-20T15:52:31+00:00

Allow free of mlock()ed pages.  This shouldn't happen, but during
developement, it occasionally did.

This patch allows us to survive that condition, while keeping the
statistics and events correct for debug.

Signed-off-by: Lee Schermerhorn 
Signed-off-by: Rik van Riel 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds