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  1. 07 9月, 2017 3 次提交
    • M
      mm, memory_hotplug: remove zone restrictions · c6f03e29
      由 Michal Hocko 提交于 
      Historically we have enforced that any kernel zone (e.g ZONE_NORMAL) has
to precede the Movable zone in the physical memory range.  The purpose
of the movable zone is, however, not bound to any physical memory
restriction.  It merely defines a class of migrateable and reclaimable
memory.

There are users (e.g.  CMA) who might want to reserve specific physical
memory ranges for their own purpose.  Moreover our pfn walkers have to
be prepared for zones overlapping in the physical range already because
we do support interleaving NUMA nodes and therefore zones can interleave
as well.  This means we can allow each memory block to be associated
with a different zone.

Loosen the current onlining semantic and allow explicit onlining type on
any memblock.  That means that online_{kernel,movable} will be allowed
regardless of the physical address of the memblock as long as it is
offline of course.  This might result in moveble zone overlapping with
other kernel zones.  Default onlining then becomes a bit tricky but
still sensible.  echo online > memoryXY/state will online the given
block to

	1) the default zone if the given range is outside of any zone
	2) the enclosing zone if such a zone doesn't interleave with
	   any other zone
        3) the default zone if more zones interleave for this range

where default zone is movable zone only if movable_node is enabled
otherwise it is a kernel zone.

Here is an example of the semantic with (movable_node is not present but
it work in an analogous way). We start with following memblocks, all of
them offline:

  memory34/valid_zones:Normal Movable
  memory35/valid_zones:Normal Movable
  memory36/valid_zones:Normal Movable
  memory37/valid_zones:Normal Movable
  memory38/valid_zones:Normal Movable
  memory39/valid_zones:Normal Movable
  memory40/valid_zones:Normal Movable
  memory41/valid_zones:Normal Movable

Now, we online block 34 in default mode and block 37 as movable

  root@test1:/sys/devices/system/node/node1# echo online > memory34/state
  root@test1:/sys/devices/system/node/node1# echo online_movable > memory37/state
  memory34/valid_zones:Normal
  memory35/valid_zones:Normal Movable
  memory36/valid_zones:Normal Movable
  memory37/valid_zones:Movable
  memory38/valid_zones:Normal Movable
  memory39/valid_zones:Normal Movable
  memory40/valid_zones:Normal Movable
  memory41/valid_zones:Normal Movable

As we can see all other blocks can still be onlined both into Normal and
Movable zones and the Normal is default because the Movable zone spans
only block37 now.

  root@test1:/sys/devices/system/node/node1# echo online_movable > memory41/state
  memory34/valid_zones:Normal
  memory35/valid_zones:Normal Movable
  memory36/valid_zones:Normal Movable
  memory37/valid_zones:Movable
  memory38/valid_zones:Movable Normal
  memory39/valid_zones:Movable Normal
  memory40/valid_zones:Movable Normal
  memory41/valid_zones:Movable

Now the default zone for blocks 37-41 has changed because movable zone
spans that range.

  root@test1:/sys/devices/system/node/node1# echo online_kernel > memory39/state
  memory34/valid_zones:Normal
  memory35/valid_zones:Normal Movable
  memory36/valid_zones:Normal Movable
  memory37/valid_zones:Movable
  memory38/valid_zones:Normal Movable
  memory39/valid_zones:Normal
  memory40/valid_zones:Movable Normal
  memory41/valid_zones:Movable

Note that the block 39 now belongs to the zone Normal and so block38
falls into Normal by default as well.

For completness

  root@test1:/sys/devices/system/node/node1# for i in memory[34]?
  do
	echo online > $i/state 2>/dev/null
  done

  memory34/valid_zones:Normal
  memory35/valid_zones:Normal
  memory36/valid_zones:Normal
  memory37/valid_zones:Movable
  memory38/valid_zones:Normal
  memory39/valid_zones:Normal
  memory40/valid_zones:Movable
  memory41/valid_zones:Movable

Implementation wise the change is quite straightforward.  We can get rid
of allow_online_pfn_range altogether.  online_pages allows only offline
nodes already.  The original default_zone_for_pfn will become
default_kernel_zone_for_pfn.  New default_zone_for_pfn implements the
above semantic.  zone_for_pfn_range is slightly reorganized to implement
kernel and movable online type explicitly and MMOP_ONLINE_KEEP becomes a
catch all default behavior.

Link: http://lkml.kernel.org/r/20170714121233.16861-3-mhocko@kernel.orgSigned-off-by: NMichal Hocko <mhocko@suse.com>
Acked-by: NJoonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: NVlastimil Babka <vbabka@suse.cz>
Acked-by: NReza Arbab <arbab@linux.vnet.ibm.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Yasuaki Ishimatsu <yasu.isimatu@gmail.com>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Cc: Kani Toshimitsu <toshi.kani@hpe.com>
Cc: <slaoub@gmail.com>
Cc: Daniel Kiper <daniel.kiper@oracle.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: <linux-api@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      c6f03e29
    • M
      mm, memory_hotplug: display allowed zones in the preferred ordering · e5e68930
      由 Michal Hocko 提交于 
      Prior to commit f1dd2cd1 ("mm, memory_hotplug: do not associate
hotadded memory to zones until online") we used to allow to change the
valid zone types of a memory block if it is adjacent to a different zone
type.

This fact was reflected in memoryNN/valid_zones by the ordering of
printed zones.  The first one was default (echo online > memoryNN/state)
and the other one could be onlined explicitly by online_{movable,kernel}.

This behavior was removed by the said patch and as such the ordering was
not all that important.  In most cases a kernel zone would be default
anyway.  The only exception is movable_node handled by "mm,
memory_hotplug: support movable_node for hotpluggable nodes".

Let's reintroduce this behavior again because later patch will remove
the zone overlap restriction and so user will be allowed to online
kernel resp.  movable block regardless of its placement.  Original
behavior will then become significant again because it would be
non-trivial for users to see what is the default zone to online into.

Implementation is really simple.  Pull out zone selection out of
move_pfn_range into zone_for_pfn_range helper and use it in
show_valid_zones to display the zone for default onlining and then both
kernel and movable if they are allowed.  Default online zone is not
duplicated.

Link: http://lkml.kernel.org/r/20170714121233.16861-2-mhocko@kernel.orgSigned-off-by: NMichal Hocko <mhocko@suse.com>
Acked-by: NJoonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: NVlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Reza Arbab <arbab@linux.vnet.ibm.com>
Cc: Yasuaki Ishimatsu <yasu.isimatu@gmail.com>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Cc: Kani Toshimitsu <toshi.kani@hpe.com>
Cc: <slaoub@gmail.com>
Cc: Daniel Kiper <daniel.kiper@oracle.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      e5e68930
    • C
      drm/i915: wire up shrinkctl->nr_scanned · 912d572d
      由 Chris Wilson 提交于 
      shrink_slab() allows us to report back the number of objects we
successfully scanned (out of the target shrinkctl->nr_to_scan).  As
report the number of pages owned by each GEM object as a separate item
to the shrinker, we cannot precisely control the number of shrinker
objects we scan on each pass; and indeed may free more than requested.
If we fail to tell the shrinker about the number of objects we process,
it will continue to hold a grudge against us as any objects left
unscanned are added to the next reclaim -- and so we will keep on
"unfairly" shrinking our own slab in comparison to other slabs.

Link: http://lkml.kernel.org/r/20170822135325.9191-2-chris@chris-wilson.co.ukSigned-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Shaohua Li <shli@fb.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Pekka Enberg <penberg@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      912d572d
  3. 02 9月, 2017 4 次提交
  5. 01 9月, 2017 33 次提交