25 May, 2010
4 commits
-
Ordinarily when a high-order allocation fails, direct reclaim is entered
to free pages to satisfy the allocation. With this patch, it is
determined if an allocation failed due to external fragmentation instead
of low memory and if so, the calling process will compact until a suitable
page is freed. Compaction by moving pages in memory is considerably
cheaper than paging out to disk and works where there are locked pages or
no swap. If compaction fails to free a page of a suitable size, then
reclaim will still occur.Direct compaction returns as soon as possible. As each block is
compacted, it is checked if a suitable page has been freed and if so, it
returns.[akpm@linux-foundation.org: Fix build errors]
[aarcange@redhat.com: fix count_vm_event preempt in memory compaction direct reclaim]
Signed-off-by: Mel Gorman
Acked-by: Rik van Riel
Reviewed-by: Minchan Kim
Cc: KOSAKI Motohiro
Cc: Christoph Lameter
Cc: KAMEZAWA Hiroyuki
Signed-off-by: Andrea Arcangeli
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
This patch is the core of a mechanism which compacts memory in a zone by
relocating movable pages towards the end of the zone.A single compaction run involves a migration scanner and a free scanner.
Both scanners operate on pageblock-sized areas in the zone. The migration
scanner starts at the bottom of the zone and searches for all movable
pages within each area, isolating them onto a private list called
migratelist. The free scanner starts at the top of the zone and searches
for suitable areas and consumes the free pages within making them
available for the migration scanner. The pages isolated for migration are
then migrated to the newly isolated free pages.[aarcange@redhat.com: Fix unsafe optimisation]
[mel@csn.ul.ie: do not schedule work on other CPUs for compaction]
Signed-off-by: Mel Gorman
Acked-by: Rik van Riel
Reviewed-by: Minchan Kim
Cc: KOSAKI Motohiro
Cc: Christoph Lameter
Cc: KAMEZAWA Hiroyuki
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The fragmentation fragmentation index, is only meaningful if an allocation
would fail and indicates what the failure is due to. A value of -1 such
as in many of the examples above states that the allocation would succeed.
If it would fail, the value is between 0 and 1. A value tending towards
0 implies the allocation failed due to a lack of memory. A value tending
towards 1 implies it failed due to external fragmentation.For the most part, the huge page size will be the size of interest but not
necessarily so it is exported on a per-order and per-zo basis via
/sys/kernel/debug/extfrag/extfrag_index> cat /sys/kernel/debug/extfrag/extfrag_index
Node 0, zone DMA -1.000 -1.000 -1.000 -1.000 -1.000 -1.000 -1.000 -1.00
Node 0, zone Normal -1.000 -1.000 -1.000 -1.000 -1.000 -1.000 -1.000 0.954Signed-off-by: Mel Gorman
Reviewed-by: Minchan Kim
Acked-by: Rik van Riel
Reviewed-by: Christoph Lameter
Cc: KOSAKI Motohiro
Cc: KAMEZAWA Hiroyuki
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The unusable free space index measures how much of the available free
memory cannot be used to satisfy an allocation of a given size and is a
value between 0 and 1. The higher the value, the more of free memory is
unusable and by implication, the worse the external fragmentation is. For
the most part, the huge page size will be the size of interest but not
necessarily so it is exported on a per-order and per-zone basis via
/sys/kernel/debug/extfrag/unusable_index.> cat /sys/kernel/debug/extfrag/unusable_index
Node 0, zone DMA 0.000 0.000 0.000 0.001 0.005 0.013 0.021 0.037 0.037 0.101 0.230
Node 0, zone Normal 0.000 0.000 0.000 0.001 0.002 0.002 0.005 0.015 0.028 0.028 0.054[akpm@linux-foundation.org: Fix allnoconfig]
Signed-off-by: Mel Gorman
Reviewed-by: Minchan Kim
Reviewed-by: KOSAKI Motohiro
Reviewed-by: Christoph Lameter
Cc: Rik van Riel
Cc: KAMEZAWA Hiroyuki
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
30 Mar, 2010
1 commit
-
…it slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
07 Mar, 2010
1 commit
-
commit e815af95 ("change all_unreclaimable zone member to flags") changed
all_unreclaimable member to bit flag. But it had an undesireble side
effect. free_one_page() is one of most hot path in linux kernel and
increasing atomic ops in it can reduce kernel performance a bit.Thus, this patch revert such commit partially. at least
all_unreclaimable shouldn't share memory word with other zone flags.[akpm@linux-foundation.org: fix patch interaction]
Signed-off-by: KOSAKI Motohiro
Cc: David Rientjes
Cc: Wu Fengguang
Cc: KAMEZAWA Hiroyuki
Cc: Minchan Kim
Cc: Huang Shijie
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
05 Jan, 2010
2 commits
-
Remove the pageset notifier since it only marks that a processor
exists on a specific node. Move that code into the vmstat notifier.Signed-off-by: Christoph Lameter
Signed-off-by: Tejun Heo -
Use the per cpu allocator functionality to avoid per cpu arrays in struct zone.
This drastically reduces the size of struct zone for systems with large
amounts of processors and allows placement of critical variables of struct
zone in one cacheline even on very large systems.Another effect is that the pagesets of one processor are placed near one
another. If multiple pagesets from different zones fit into one cacheline
then additional cacheline fetches can be avoided on the hot paths when
allocating memory from multiple zones.Bootstrap becomes simpler if we use the same scheme for UP, SMP, NUMA. #ifdefs
are reduced and we can drop the zone_pcp macro.Hotplug handling is also simplified since cpu alloc can bring up and
shut down cpu areas for a specific cpu as a whole. So there is no need to
allocate or free individual pagesets.V7-V8:
- Explain chicken egg dilemmna with percpu allocator.V4-V5:
- Fix up cases where per_cpu_ptr is called before irq disable
- Integrate the bootstrap logic that was separate before.tj: Build failure in pageset_cpuup_callback() due to missing ret
variable fixed.Reviewed-by: Mel Gorman
Signed-off-by: Christoph Lameter
Signed-off-by: Tejun Heo
16 Dec, 2009
2 commits
-
If reclaim fails to make sufficient progress, the priority is raised.
Once the priority is higher, kswapd starts waiting on congestion.
However, if the zone is below the min watermark then kswapd needs to
continue working without delay as there is a danger of an increased rate
of GFP_ATOMIC allocation failure.This patch changes the conditions under which kswapd waits on congestion
by only going to sleep if the min watermarks are being met.[mel@csn.ul.ie: add stats to track how relevant the logic is]
[mel@csn.ul.ie: make kswapd only check its own zones and rename the relevant counters]
Signed-off-by: KOSAKI Motohiro
Signed-off-by: Mel Gorman
Reviewed-by: Rik van Riel
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
After kswapd balances all zones in a pgdat, it goes to sleep. In the
event of no IO congestion, kswapd can go to sleep very shortly after the
high watermark was reached. If there are a constant stream of allocations
from parallel processes, it can mean that kswapd went to sleep too quickly
and the high watermark is not being maintained for sufficient length time.This patch makes kswapd go to sleep as a two-stage process. It first
tries to sleep for HZ/10. If it is woken up by another process or the
high watermark is no longer met, it's considered a premature sleep and
kswapd continues work. Otherwise it goes fully to sleep.This adds more counters to distinguish between fast and slow breaches of
watermarks. A "fast" premature sleep is one where the low watermark was
hit in a very short time after kswapd going to sleep. A "slow" premature
sleep indicates that the high watermark was breached after a very short
interval.Signed-off-by: Mel Gorman
Cc: Frans Pop
Cc: KOSAKI Motohiro
Cc: Rik van Riel
Cc: Christoph Lameter
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
29 Oct, 2009
1 commit
-
This patch updates percpu related symbols under kernel/ and mm/ such
that percpu symbols are unique and don't clash with local symbols.
This serves two purposes of decreasing the possibility of global
percpu symbol collision and allowing dropping per_cpu__ prefix from
percpu symbols.* kernel/lockdep.c: s/lock_stats/cpu_lock_stats/
* kernel/sched.c: s/init_rq_rt/init_rt_rq_var/ (any better idea?)
s/sched_group_cpus/sched_groups/* kernel/softirq.c: s/ksoftirqd/run_ksoftirqd/a
* kernel/softlockup.c: s/(*)_timestamp/softlockup_\1_ts/
s/watchdog_task/softlockup_watchdog/
s/timestamp/ts/ for local variables* kernel/time/timer_stats: s/lookup_lock/tstats_lookup_lock/
* mm/slab.c: s/reap_work/slab_reap_work/
s/reap_node/slab_reap_node/* mm/vmstat.c: local variable changed to avoid collision with vmstat_work
Partly based on Rusty Russell's "alloc_percpu: rename percpu vars
which cause name clashes" patch.Signed-off-by: Tejun Heo
Acked-by: (slab/vmstat) Christoph Lameter
Reviewed-by: Christoph Lameter
Cc: Rusty Russell
Cc: Ingo Molnar
Cc: Thomas Gleixner
Cc: Andrew Morton
Cc: Nick Piggin
22 Sep, 2009
3 commits
-
If the system is running a heavy load of processes then concurrent reclaim
can isolate a large number of pages from the LRU. /proc/vmstat and the
output generated for an OOM do not show how many pages were isolated.This has been observed during process fork bomb testing (mstctl11 in LTP).
This patch shows the information about isolated pages.
Reproduced via:
-----------------------
% ./hackbench 140 process 1000
=> OOM occuractive_anon:146 inactive_anon:0 isolated_anon:49245
active_file:79 inactive_file:18 isolated_file:113
unevictable:0 dirty:0 writeback:0 unstable:0 buffer:39
free:370 slab_reclaimable:309 slab_unreclaimable:5492
mapped:53 shmem:15 pagetables:28140 bounce:0Signed-off-by: KOSAKI Motohiro
Acked-by: Rik van Riel
Acked-by: Wu Fengguang
Reviewed-by: Minchan Kim
Cc: Hugh Dickins
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Recently we encountered OOM problems due to memory use of the GEM cache.
Generally a large amuont of Shmem/Tmpfs pages tend to create a memory
shortage problem.We often use the following calculation to determine the amount of shmem
pages:shmem = NR_ACTIVE_ANON + NR_INACTIVE_ANON - NR_ANON_PAGES
however the expression does not consider isolated and mlocked pages.
This patch adds explicit accounting for pages used by shmem and tmpfs.
Signed-off-by: KOSAKI Motohiro
Acked-by: Rik van Riel
Reviewed-by: Christoph Lameter
Acked-by: Wu Fengguang
Cc: David Rientjes
Cc: Hugh Dickins
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The amount of memory allocated to kernel stacks can become significant and
cause OOM conditions. However, we do not display the amount of memory
consumed by stacks.Add code to display the amount of memory used for stacks in /proc/meminfo.
Signed-off-by: KOSAKI Motohiro
Reviewed-by: Christoph Lameter
Reviewed-by: Minchan Kim
Reviewed-by: Rik van Riel
Cc: David Rientjes
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
17 Jun, 2009
5 commits
-
On NUMA machines, the administrator can configure zone_reclaim_mode that
is a more targetted form of direct reclaim. On machines with large NUMA
distances for example, a zone_reclaim_mode defaults to 1 meaning that
clean unmapped pages will be reclaimed if the zone watermarks are not
being met.There is a heuristic that determines if the scan is worthwhile but it is
possible that the heuristic will fail and the CPU gets tied up scanning
uselessly. Detecting the situation requires some guesswork and
experimentation so this patch adds a counter "zreclaim_failed" to
/proc/vmstat. If during high CPU utilisation this counter is increasing
rapidly, then the resolution to the problem may be to set
/proc/sys/vm/zone_reclaim_mode to 0.[akpm@linux-foundation.org: name things consistently]
Signed-off-by: Mel Gorman
Reviewed-by: Rik van Riel
Cc: Christoph Lameter
Reviewed-by: KOSAKI Motohiro
Cc: Wu Fengguang
Cc:
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Currently, nobody wants to turn UNEVICTABLE_LRU off. Thus this
configurability is unnecessary.Signed-off-by: KOSAKI Motohiro
Cc: Johannes Weiner
Cc: Andi Kleen
Acked-by: Minchan Kim
Cc: David Woodhouse
Cc: Matt Mackall
Cc: Rik van Riel
Cc: Lee Schermerhorn
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The lru->nr_saved_scan's are not meaningful counters for even kernel
developers. They typically are smaller than 32 and are always 0 for large
lists. So remove them from /proc/zoneinfo.Hopefully this interface change won't break too many scripts.
/proc/zoneinfo is too unstructured to be script friendly, and I wonder the
affected scripts - if there are any - are still bleeding since the not
long ago commit "vmscan: split LRU lists into anon & file sets", which
also touched the "scanned" line :)If we are to re-export accumulated vmscan counts in the future, they can
go to new lines in /proc/zoneinfo instead of the current form, or to
/sys/devices/system/node/node0/meminfo?Signed-off-by: Wu Fengguang
Acked-by: Rik van Riel
Cc: Nick Piggin
Acked-by: Christoph Lameter
Cc: Peter Zijlstra
Cc: KOSAKI Motohiro
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The vmscan batching logic is twisting. Move it into a standalone function
nr_scan_try_batch() and document it. No behavior change.Signed-off-by: Wu Fengguang
Acked-by: Rik van Riel
Cc: Nick Piggin
Cc: Christoph Lameter
Acked-by: Peter Zijlstra
Acked-by: KOSAKI Motohiro
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
ALLOC_WMARK_MIN, ALLOC_WMARK_LOW and ALLOC_WMARK_HIGH determin whether
pages_min, pages_low or pages_high is used as the zone watermark when
allocating the pages. Two branches in the allocator hotpath determine
which watermark to use.This patch uses the flags as an array index into a watermark array that is
indexed with WMARK_* defines accessed via helpers. All call sites that
use zone->pages_* are updated to use the helpers for accessing the values
and the array offsets for setting.Signed-off-by: Mel Gorman
Reviewed-by: Christoph Lameter
Cc: KOSAKI Motohiro
Cc: Pekka Enberg
Cc: Peter Zijlstra
Cc: Nick Piggin
Cc: Dave Hansen
Cc: Lee Schermerhorn
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
18 May, 2009
1 commit
-
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
03 Apr, 2009
1 commit
-
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
01 Apr, 2009
1 commit
-
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
30 Mar, 2009
1 commit
-
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
01 Jan, 2009
1 commit
-
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
23 Oct, 2008
4 commits
-
Signed-off-by: Alexey Dobriyan
Acked-by: Christoph Lameter -
Signed-off-by: Alexey Dobriyan
Acked-by: Christoph Lameter -
Signed-off-by: Alexey Dobriyan
-
Signed-off-by: Alexey Dobriyan
20 Oct, 2008
7 commits
-
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 -
Add NR_MLOCK zone page state, which provides a (conservative) count of
mlocked pages (actually, the number of mlocked pages moved off the LRU).Reworked by lts to fit in with the modified mlock page support in the
Reclaim Scalability series.[kosaki.motohiro@jp.fujitsu.com: fix incorrect Mlocked field of /proc/meminfo]
[lee.schermerhorn@hp.com: mlocked-pages: add event counting with statistics]
Signed-off-by: Nick Piggin
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 -
Report unevictable pages per zone and system wide.
Kosaki Motohiro added support for memory controller unevictable
statistics.[riel@redhat.com: fix printk in show_free_areas()]
[akpm@linux-foundation.org: fix units in /proc/vmstats]
Signed-off-by: Lee Schermerhorn
Signed-off-by: Rik van Riel
Signed-off-by: KOSAKI Motohiro
Debugged-by: Hiroshi Shimamoto
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Fix to unevictable-lru-page-statistics.patch
Add unevictable lru infrastructure vm events to the statistics patch.
Rename the "NORECL_" and "noreclaim_" symbols and text strings to
"UNEVICTABLE_" and "unevictable_", respectively.Currently, both the infrastructure and the mlocked pages event are
added by a single patch later in the series. This makes it difficult
to add or rework the incremental patches. The events actually "belong"
with the stats, so pull them up to here.Also, restore the event counting to putback_lru_page(). This was removed
from previous patch in series where it was "misplaced". The actual events
weren't defined that early.Signed-off-by: Lee Schermerhorn
Cc: Rik van Riel
Reviewed-by: KOSAKI Motohiro
Cc: KAMEZAWA Hiroyuki
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
We avoid evicting and scanning anonymous pages for the most part, but
under some workloads we can end up with most of memory filled with
anonymous pages. At that point, we suddenly need to clear the referenced
bits on all of memory, which can take ages on very large memory systems.We can reduce the maximum number of pages that need to be scanned by not
taking the referenced state into account when deactivating an anonymous
page. After all, every anonymous page starts out referenced, so why
check?If an anonymous page gets referenced again before it reaches the end of
the inactive list, we move it back to the active list.To keep the maximum amount of necessary work reasonable, we scale the
active to inactive ratio with the size of memory, using the formula
active:inactive ratio = sqrt(memory in GB * 10).Kswapd CPU use now seems to scale by the amount of pageout bandwidth,
instead of by the amount of memory present in the system.[kamezawa.hiroyu@jp.fujitsu.com: fix OOM with memcg]
[kamezawa.hiroyu@jp.fujitsu.com: memcg: lru scan fix]
Signed-off-by: Rik van Riel
Signed-off-by: KOSAKI Motohiro
Signed-off-by: KAMEZAWA Hiroyuki
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Split the LRU lists in two, one set for pages that are backed by real file
systems ("file") and one for pages that are backed by memory and swap
("anon"). The latter includes tmpfs.The advantage of doing this is that the VM will not have to scan over lots
of anonymous pages (which we generally do not want to swap out), just to
find the page cache pages that it should evict.This patch has the infrastructure and a basic policy to balance how much
we scan the anon lists and how much we scan the file lists. The big
policy changes are in separate patches.[lee.schermerhorn@hp.com: collect lru meminfo statistics from correct offset]
[kosaki.motohiro@jp.fujitsu.com: prevent incorrect oom under split_lru]
[kosaki.motohiro@jp.fujitsu.com: fix pagevec_move_tail() doesn't treat unevictable page]
[hugh@veritas.com: memcg swapbacked pages active]
[hugh@veritas.com: splitlru: BDI_CAP_SWAP_BACKED]
[akpm@linux-foundation.org: fix /proc/vmstat units]
[nishimura@mxp.nes.nec.co.jp: memcg: fix handling of shmem migration]
[kosaki.motohiro@jp.fujitsu.com: adjust Quicklists field of /proc/meminfo]
[kosaki.motohiro@jp.fujitsu.com: fix style issue of get_scan_ratio()]
Signed-off-by: Rik van Riel
Signed-off-by: Lee Schermerhorn
Signed-off-by: KOSAKI Motohiro
Signed-off-by: Hugh Dickins
Signed-off-by: Daisuke Nishimura
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Currently we are defining explicit variables for the inactive and active
list. An indexed array can be more generic and avoid repeating similar
code in several places in the reclaim code.We are saving a few bytes in terms of code size:
Before:
text data bss dec hex filename
4097753 573120 4092484 8763357 85b7dd vmlinuxAfter:
text data bss dec hex filename
4097729 573120 4092484 8763333 85b7c5 vmlinuxHaving an easy way to add new lru lists may ease future work on the
reclaim code.Signed-off-by: Rik van Riel
Signed-off-by: Lee Schermerhorn
Signed-off-by: Christoph Lameter
Signed-off-by: KOSAKI Motohiro
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
28 Aug, 2008
1 commit
-
Ordinarily, memory holes in flatmem still have a valid memmap and is safe
to use. However, an architecture (ARM) frees up the memmap backing memory
holes on the assumption it is never used. /proc/pagetypeinfo reads the
whole range of pages in a zone believing that the memmap is valid and that
pfn_valid will return false if it is not. On ARM, freeing the memmap breaks
the page->zone linkages even though pfn_valid() returns true and the kernel
can oops shortly afterwards due to accessing a bogus struct zone *.This patch lets architectures say when FLATMEM can have holes in the
memmap. Rather than an expensive check for valid memory, /proc/pagetypeinfo
will confirm that the page linkages are still valid by checking page->zone
is still the expected zone. The lookup of page_zone is safe as there is a
limited range of memory that is accessed when calling page_zone. Even if
page_zone happens to return the correct zone, the impact is that the counters
in /proc/pagetypeinfo are slightly off but fragmentation monitoring is
unlikely to be relevant on an embedded system.Reported-by: H Hartley Sweeten
Signed-off-by: Mel Gorman
Tested-by: H Hartley Sweeten
Signed-off-by: Russell King
25 Jul, 2008
1 commit
-
This patch adds proper extern declarations for five variables in
include/linux/vmstat.hSigned-off-by: Adrian Bunk
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
24 May, 2008
1 commit
-
Change references from for_each_cpu_mask to for_each_cpu_mask_nr
where appropriateReviewed-by: Paul Jackson
Reviewed-by: Christoph Lameter
Signed-off-by: Mike Travis
Signed-off-by: Ingo Molnar
Signed-off-by: Thomas Gleixner
13 May, 2008
1 commit
-
When accessing cpu_online_map, we should prevent dynamic changing
of cpu_online_map by get_online_cpus().Unfortunately, all_vm_events() doesn't do that.
Signed-off-by: KOSAKI Motohiro
Acked-by: Christoph Lameter
Cc: Gautham R Shenoy
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
30 Apr, 2008
1 commit
-
Fuse will use temporary buffers to write back dirty data from memory mappings
(normal writes are done synchronously). This is needed, because there cannot
be any guarantee about the time in which a write will complete.By using temporary buffers, from the MM's point if view the page is written
back immediately. If the writeout was due to memory pressure, this
effectively migrates data from a full zone to a less full zone.This patch adds a new counter (NR_WRITEBACK_TEMP) for the number of pages used
as temporary buffers.[Lee.Schermerhorn@hp.com: add vmstat_text for NR_WRITEBACK_TEMP]
Signed-off-by: Miklos Szeredi
Cc: Christoph Lameter
Signed-off-by: Lee Schermerhorn
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
