22 Jan, 2014
2 commits
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Show num_poisoned_pages when oom, it is a little helpful to find the
reason. Also it will be emitted anytime show_mem() is called.Signed-off-by: Xishi Qiu
Suggested-by: Naoya Horiguchi
Acked-by: Michal Hocko
Acked-by: David Rientjes
Reviewed-by: Wanpeng Li
Acked-by: KOSAKI Motohiro
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Commit 4b59e6c47309 ("mm, show_mem: suppress page counts in
non-blockable contexts") introduced SHOW_MEM_FILTER_PAGE_COUNT to
suppress PFN walks on large memory machines. Commit c78e93630d15 ("mm:
do not walk all of system memory during show_mem") avoided a PFN walk in
the generic show_mem helper which removes the requirement for
SHOW_MEM_FILTER_PAGE_COUNT in that case.This patch removes PFN walkers from the arch-specific implementations
that report on a per-node or per-zone granularity. ARM and unicore32
still do a PFN walk as they report memory usage on each bank which is a
much finer granularity where the debugging information may still be of
use. As the remaining arches doing PFN walks have relatively small
amounts of memory, this patch simply removes SHOW_MEM_FILTER_PAGE_COUNT.[akpm@linux-foundation.org: fix parisc]
Signed-off-by: Mel Gorman
Acked-by: David Rientjes
Cc: Tony Luck
Cc: Russell King
Cc: James Bottomley
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
13 Nov, 2013
1 commit
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It has been reported on very large machines that show_mem is taking almost
5 minutes to display information. This is a serious problem if there is
an OOM storm. The bulk of the cost is in show_mem doing a very expensive
PFN walk to give us the following informationTotal RAM: Also available as totalram_pages
Highmem pages: Also available as totalhigh_pages
Reserved pages: Can be inferred from the zone structure
Shared pages: PFN walk required
Unshared pages: PFN walk required
Quick pages: Per-cpu walk requiredOnly the shared/unshared pages requires a full PFN walk but that
information is useless. It is also inaccurate as page pins of unshared
pages would be accounted for as shared. Even if the information was
accurate, I'm struggling to think how the shared/unshared information
could be useful for debugging OOM conditions. Maybe it was useful before
rmap existed when reclaiming shared pages was costly but it is less
relevant today.The PFN walk could be optimised a bit but why bother as the information is
useless. This patch deletes the PFN walker and infers the total RAM,
highmem and reserved pages count from struct zone. It omits the
shared/unshared page usage on the grounds that it is useless. It also
corrects the reporting of HighMem as HighMem/MovableOnly as ZONE_MOVABLE
has similar problems to HighMem with respect to lowmem/highmem exhaustion.Signed-off-by: Mel Gorman
Cc: David Rientjes
Acked-by: KOSAKI Motohiro
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
30 Apr, 2013
1 commit
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On large systems with a lot of memory, walking all RAM to determine page
types may take a half second or even more.In non-blockable contexts, the page allocator will emit a page allocation
failure warning unless __GFP_NOWARN is specified. In such contexts, irqs
are typically disabled and such a lengthy delay may even result in NMI
watchdog timeouts.To fix this, suppress the page walk in such contexts when printing the
page allocation failure warning.Signed-off-by: David Rientjes
Cc: Mel Gorman
Acked-by: Michal Hocko
Cc: Dave Hansen
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
25 May, 2011
1 commit
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Architectures that implement their own show_mem() function did not pass
the filter argument to show_free_areas() to appropriately avoid emitting
the state of nodes that are disallowed in the current context. This patch
now passes the filter argument to show_free_areas() so those nodes are now
avoided.This patch also removes the show_free_areas() wrapper around
__show_free_areas() and converts existing callers to pass an empty filter.ia64 emits additional information for each node, so skip_free_areas_zone()
must be made global to filter disallowed nodes and it is converted to use
a nid argument rather than a zone for this use case.Signed-off-by: David Rientjes
Cc: Russell King
Cc: Tony Luck
Cc: Fenghua Yu
Cc: Kyle McMartin
Cc: Helge Deller
Cc: James Bottomley
Cc: "David S. Miller"
Cc: Guan Xuetao
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
25 Mar, 2011
1 commit
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Commit ddd588b5dd55 ("oom: suppress nodes that are not allowed from
meminfo on oom kill") moved lib/show_mem.o out of lib/lib.a, which
resulted in build warnings on all architectures that implement their own
versions of show_mem():lib/lib.a(show_mem.o): In function `show_mem':
show_mem.c:(.text+0x1f4): multiple definition of `show_mem'
arch/sparc/mm/built-in.o:(.text+0xd70): first defined hereThe fix is to remove __show_mem() and add its argument to show_mem() in
all implementations to prevent this breakage.Architectures that implement their own show_mem() actually don't do
anything with the argument yet, but they could be made to filter nodes
that aren't allowed in the current context in the future just like the
generic implementation.Reported-by: Stephen Rothwell
Reported-by: James Bottomley
Suggested-by: Andrew Morton
Signed-off-by: David Rientjes
Signed-off-by: Linus Torvalds
23 Mar, 2011
1 commit
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The oom killer is extremely verbose for machines with a large number of
cpus and/or nodes. This verbosity can often be harmful if it causes other
important messages to be scrolled from the kernel log and incurs a
signicant time delay, specifically for kernels with CONFIG_NODES_SHIFT >
8.This patch causes only memory information to be displayed for nodes that
are allowed by current's cpuset when dumping the VM state. Information
for all other nodes is irrelevant to the oom condition; we don't care if
there's an abundance of memory elsewhere if we can't access it.This only affects the behavior of dumping memory information when an oom
is triggered. Other dumps, such as for sysrq+m, still display the
unfiltered form when using the existing show_mem() interface.Additionally, the per-cpu pageset statistics are extremely verbose in oom
killer output, so it is now suppressed. This removesnodes_weight(current->mems_allowed) * (1 + nr_cpus)
lines from the oom killer output.
Callers may use __show_mem(SHOW_MEM_FILTER_NODES) to filter disallowed
nodes.Signed-off-by: David Rientjes
Cc: Mel Gorman
Cc: KAMEZAWA Hiroyuki
Cc: KOSAKI Motohiro
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
07 Mar, 2010
1 commit
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Use the same log level for printk's in show_mem(), so that those messages
can be shown completely when using log level 6.Signed-off-by: WANG Cong
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
27 Jul, 2008
1 commit
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This implements a platform-independent version of show_mem().
Signed-off-by: Johannes Weiner
Cc: Richard Henderson
Cc: Ivan Kokshaysky
Cc: Haavard Skinnemoen
Cc: Bryan Wu
Cc: Chris Zankel
Cc: Ingo Molnar
Cc: Jeff Dike
Cc: David S. Miller
Cc: Paul Mundt
Cc: Heiko Carstens
Cc: Martin Schwidefsky
Cc: David Howells
Cc: Benjamin Herrenschmidt
Cc: Paul Mackerras
Cc: Yoshinori Sato
Cc: Ralf Baechle
Cc: Greg Ungerer
Cc: Geert Uytterhoeven
Cc: Roman Zippel
Cc: Hirokazu Takata
Cc: Mikael Starvik
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
