linux-toradex.git/mm/memory_hotplug.c, branch v2.6.38-rc8

Merge branch 'slub/hotplug' into slab/urgent

2011-01-15T11:28:17+00:00

thp: remove PG_buddy

2011-01-14T01:32:43+00:00

PG_buddy can be converted to _mapcount == -2.  So the PG_compound_lock can
be added to page->flags without overflowing (because of the sparse section
bits increasing) with CONFIG_X86_PAE=y and CONFIG_X86_PAT=y.  This also
has to move the memory hotplug code from _mapcount to lru.next to avoid
any risk of clashes.  We can't use lru.next for PG_buddy removal, but
memory hotplug can use lru.next even more easily than the mapcount
instead.

Signed-off-by: Andrea Arcangeli 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: migration: cleanup migrate_pages API by matching types for offlining and sync

2011-01-14T01:32:34+00:00

With the introduction of the boolean sync parameter, the API looks a
little inconsistent as offlining is still an int.  Convert offlining to a
bool for the sake of being tidy.

Signed-off-by: Mel Gorman 
Cc: Andrea Arcangeli 
Cc: KOSAKI Motohiro 
Cc: Rik van Riel 
Acked-by: Johannes Weiner 
Cc: Andy Whitcroft 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: migration: allow migration to operate asynchronously and avoid synchronous compaction in the faster path

2011-01-14T01:32:34+00:00

Migration synchronously waits for writeback if the initial passes fails.
Callers of memory compaction do not necessarily want this behaviour if the
caller is latency sensitive or expects that synchronous migration is not
going to have a significantly better success rate.

This patch adds a sync parameter to migrate_pages() allowing the caller to
indicate if wait_on_page_writeback() is allowed within migration or not.
For reclaim/compaction, try_to_compact_pages() is first called
asynchronously, direct reclaim runs and then try_to_compact_pages() is
called synchronously as there is a greater expectation that it'll succeed.

[akpm@linux-foundation.org: build/merge fix]
Signed-off-by: Mel Gorman 
Cc: Andrea Arcangeli 
Cc: KOSAKI Motohiro 
Cc: Rik van Riel 
Acked-by: Johannes Weiner 
Cc: Andy Whitcroft 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

memory hotplug: one more lock on memory hotplug

2011-01-11T15:09:50+00:00

Now, memory_hotplug_(un)lock() is used for add/remove/offline pages
for avoiding races with hibernation. But this should be held in
online_pages(), too. It seems asymmetric.

There are cases where one has to avoid a race with memory hotplug
notifier and his own local code, and hotplug v.s. hotplug.
This will add a generic solution for avoiding races. In other view,
having lock here has no big impacts. online pages is tend to be
done by udev script at el against each memory section one by one.

Then, it's better to have lock here, too.

Cc:  # 2.6.37
Reviewed-by: Christoph Lameter 
Acked-by: David Rientjes 
Signed-off-by: KAMEZAWA Hiroyuki 
Signed-off-by: Pekka Enberg

mem-hotplug: introduce {un}lock_memory_hotplug()

2010-12-02T22:51:15+00:00

Presently hwpoison is using lock_system_sleep() to prevent a race with
memory hotplug.  However lock_system_sleep() is a no-op if
CONFIG_HIBERNATION=n.  Therefore we need a new lock.

Signed-off-by: KOSAKI Motohiro 
Cc: Andi Kleen 
Cc: Kamezawa Hiroyuki 
Suggested-by: Hugh Dickins 
Acked-by: Hugh Dickins 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: do_migrate_range: reduce list_empty() check

2010-10-26T23:52:11+00:00

Simple code for reducing list_empty(&source) check.

Signed-off-by: Bob Liu 
Acked-by: KAMEZAWA Hiroyuki 
Acked-by: Wu Fengguang 
Cc: KOSAKI Motohiro 
Cc: Mel Gorman 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: do_migrate_range: exit loop if not_managed is true

2010-10-26T23:52:11+00:00

If not_managed is true all pages will be putback to lru, so break the loop
earlier to skip other pages isolate.

Signed-off-by: Bob Liu 
Acked-by: KAMEZAWA Hiroyuki 
Acked-by: Wu Fengguang 
Cc: KOSAKI Motohiro 
Cc: Mel Gorman 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm/memory_hotplug.c: make scan_lru_pages() static

2010-10-26T23:52:10+00:00

Reported-by: KOSAKI Motohiro 
Cc: KAMEZAWA Hiroyuki 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

memory hotplug: unify is_removable and offline detection code

2010-10-26T23:52:06+00:00

Now, sysfs interface of memory hotplug shows whether the section is
removable or not.  But it checks only migrateype of pages and doesn't
check details of cluster of pages.

Next, memory hotplug's set_migratetype_isolate() has the same kind of
check, too.

This patch adds the function __count_unmovable_pages() and makes above 2
checks to use the same logic.  Then, is_removable and hotremove code uses
the same logic.  No changes in the hotremove logic itself.

TODO: need to find a way to check RECLAMABLE. But, considering bit,
      calling shrink_slab() against a range before starting memory hotremove
      sounds better. If so, this patch's logic doesn't need to be changed.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: KAMEZAWA Hiroyuki 
Reported-by: Michal Hocko 
Cc: Wu Fengguang 
Cc: Mel Gorman 
Cc: KAMEZAWA Hiroyuki 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds