1. 03 Dec, 2014 1 commit
  2. 22 Jan, 2014 2 commits
  3. 13 Nov, 2013 1 commit
    • Mel Gorman's avatar
      mm: do not walk all of system memory during show_mem · c78e9363
      Mel Gorman authored
      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 information
        Total 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 required
      Only 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: default avatarMel Gorman <mgorman@suse.de>
      Cc: David Rientjes <rientjes@google.com>
      Acked-by: default avatarKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
  4. 29 Apr, 2013 1 commit
  5. 25 May, 2011 1 commit
    • David Rientjes's avatar
      arch, mm: filter disallowed nodes from arch specific show_mem functions · 7bf02ea2
      David Rientjes authored
      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
      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: default avatarDavid Rientjes <rientjes@google.com>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      Cc: Kyle McMartin <kyle@mcmartin.ca>
      Cc: Helge Deller <deller@gmx.de>
      Cc: James Bottomley <jejb@parisc-linux.org>
      Cc: "David S. Miller" <davem@davemloft.net>
      Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
  6. 25 Mar, 2011 1 commit
  7. 23 Mar, 2011 1 commit
    • David Rientjes's avatar
      oom: suppress nodes that are not allowed from meminfo on oom kill · ddd588b5
      David Rientjes authored
      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 >
      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 removes
      	nodes_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
      Signed-off-by: default avatarDavid Rientjes <rientjes@google.com>
      Cc: Mel Gorman <mel@csn.ul.ie>
      Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
      Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
  8. 06 Mar, 2010 1 commit
  9. 26 Jul, 2008 1 commit
    • Johannes Weiner's avatar
      lib: generic show_mem() · 454c63b0
      Johannes Weiner authored
      This implements a platform-independent version of show_mem().
      Signed-off-by: default avatarJohannes Weiner <hannes@saeurebad.de>
      Cc: Richard Henderson <rth@twiddle.net>
      Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
      Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
      Cc: Bryan Wu <cooloney@kernel.org>
      Cc: Chris Zankel <chris@zankel.net>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Jeff Dike <jdike@addtoit.com>
      Cc: David S. Miller <davem@davemloft.net>
      Cc: Paul Mundt <lethal@linux-sh.org>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: David Howells <dhowells@redhat.com>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Cc: Greg Ungerer <gerg@uclinux.org>
      Cc: Geert Uytterhoeven <geert@linux-m68k.org>
      Cc: Roman Zippel <zippel@linux-m68k.org>
      Cc: Hirokazu Takata <takata@linux-m32r.org>
      Cc: Mikael Starvik <starvik@axis.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>