linux.git/include/linux/rmap.h, branch v4.14-rc4

lib/interval_tree: fast overlap detection

2017-09-09T01:26:49+00:00

Allow interval trees to quickly check for overlaps to avoid unnecesary
tree lookups in interval_tree_iter_first().

As of this patch, all interval tree flavors will require using a
'rb_root_cached' such that we can have the leftmost node easily
available.  While most users will make use of this feature, those with
special functions (in addition to the generic insert, delete, search
calls) will avoid using the cached option as they can do funky things
with insertions -- for example, vma_interval_tree_insert_after().

[jglisse@redhat.com: fix deadlock from typo vm_lock_anon_vma()]
  Link: http://lkml.kernel.org/r/20170808225719.20723-1-jglisse@redhat.com
Link: http://lkml.kernel.org/r/20170719014603.19029-12-dave@stgolabs.net
Signed-off-by: Davidlohr Bueso 
Signed-off-by: Jérôme Glisse 
Acked-by: Christian König 
Acked-by: Peter Zijlstra (Intel) 
Acked-by: Doug Ledford 
Acked-by: Michael S. Tsirkin 
Cc: David Airlie 
Cc: Jason Wang 
Cc: Christian Benvenuti 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: thp: introduce separate TTU flag for thp freezing

2017-09-09T01:26:45+00:00

TTU_MIGRATION is used to convert pte into migration entry until thp
split completes.  This behavior conflicts with thp migration added later
patches, so let's introduce a new TTU flag specifically for freezing.

try_to_unmap() is used both for thp split (via freeze_page()) and page
migration (via __unmap_and_move()).  In freeze_page(), ttu_flag given
for head page is like below (assuming anonymous thp):

    (TTU_IGNORE_MLOCK | TTU_IGNORE_ACCESS | TTU_RMAP_LOCKED | \
     TTU_MIGRATION | TTU_SPLIT_HUGE_PMD)

and ttu_flag given for tail pages is:

    (TTU_IGNORE_MLOCK | TTU_IGNORE_ACCESS | TTU_RMAP_LOCKED | \
     TTU_MIGRATION)

__unmap_and_move() calls try_to_unmap() with ttu_flag:

    (TTU_MIGRATION | TTU_IGNORE_MLOCK | TTU_IGNORE_ACCESS)

Now I'm trying to insert a branch for thp migration at the top of
try_to_unmap_one() like below

static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
                       unsigned long address, void *arg)
  {
          ...
          /* PMD-mapped THP migration entry */
          if (!pvmw.pte && (flags & TTU_MIGRATION)) {
              if (!PageAnon(page))
                  continue;

              set_pmd_migration_entry(&pvmw, page);
              continue;
          }
	  ...
  }

so try_to_unmap() for tail pages called by thp split can go into thp
migration code path (which converts *pmd* into migration entry), while
the expectation is to freeze thp (which converts *pte* into migration
entry.)

I detected this failure as a "bad page state" error in a testcase where
split_huge_page() is called from queue_pages_pte_range().

Link: http://lkml.kernel.org/r/20170717193955.20207-4-zi.yan@sent.com
Signed-off-by: Naoya Horiguchi 
Signed-off-by: Zi Yan 
Acked-by: Kirill A. Shutemov 
Cc: "H. Peter Anvin" 
Cc: Anshuman Khandual 
Cc: Dave Hansen 
Cc: David Nellans 
Cc: Ingo Molnar 
Cc: Mel Gorman 
Cc: Minchan Kim 
Cc: Thomas Gleixner 
Cc: Vlastimil Babka 
Cc: Andrea Arcangeli 
Cc: Michal Hocko 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: remove SWAP_[SUCCESS|AGAIN|FAIL]

2017-05-03T22:52:10+00:00

There is no user for it.  Remove it.

[minchan@kernel.org: use false instead of SWAP_FAIL]
  Link: http://lkml.kernel.org/r/20170316053313.GA19241@bbox
Link: http://lkml.kernel.org/r/1489555493-14659-11-git-send-email-minchan@kernel.org
Signed-off-by: Minchan Kim 
Cc: Anshuman Khandual 
Cc: Hillf Danton 
Cc: Johannes Weiner 
Cc: Kirill A. Shutemov 
Cc: Michal Hocko 
Cc: Naoya Horiguchi 
Cc: Vlastimil Babka 
Cc: Sergey Senozhatsky 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: make rmap_one boolean function

2017-05-03T22:52:10+00:00

rmap_one's return value controls whether rmap_work should contine to
scan other ptes or not so it's target for changing to boolean.  Return
true if the scan should be continued.  Otherwise, return false to stop
the scanning.

This patch makes rmap_one's return value to boolean.

Link: http://lkml.kernel.org/r/1489555493-14659-10-git-send-email-minchan@kernel.org
Signed-off-by: Minchan Kim 
Cc: Anshuman Khandual 
Cc: Hillf Danton 
Cc: Johannes Weiner 
Cc: Kirill A. Shutemov 
Cc: Michal Hocko 
Cc: Naoya Horiguchi 
Cc: Vlastimil Babka 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: make rmap_walk() return void

2017-05-03T22:52:10+00:00

There is no user of the return value from rmap_walk() and friends so
this patch makes them void-returning functions.

Link: http://lkml.kernel.org/r/1489555493-14659-9-git-send-email-minchan@kernel.org
Signed-off-by: Minchan Kim 
Cc: Anshuman Khandual 
Cc: Hillf Danton 
Cc: Johannes Weiner 
Cc: Kirill A. Shutemov 
Cc: Michal Hocko 
Cc: Naoya Horiguchi 
Cc: Vlastimil Babka 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: make ttu's return boolean

2017-05-03T22:52:10+00:00

try_to_unmap() returns SWAP_SUCCESS or SWAP_FAIL so it's suitable for
boolean return.  This patch changes it.

Link: http://lkml.kernel.org/r/1489555493-14659-8-git-send-email-minchan@kernel.org
Signed-off-by: Minchan Kim 
Cc: Naoya Horiguchi 
Cc: Anshuman Khandual 
Cc: Hillf Danton 
Cc: Johannes Weiner 
Cc: Kirill A. Shutemov 
Cc: Michal Hocko 
Cc: Vlastimil Babka 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: remove SWAP_MLOCK in ttu

2017-05-03T22:52:10+00:00

ttu doesn't need to return SWAP_MLOCK.  Instead, just return SWAP_FAIL
because it means the page is not-swappable so it should move to another
LRU list(active or unevictable).  putback friends will move it to right
list depending on the page's LRU flag.

Link: http://lkml.kernel.org/r/1489555493-14659-6-git-send-email-minchan@kernel.org
Signed-off-by: Minchan Kim 
Cc: Anshuman Khandual 
Cc: Hillf Danton 
Cc: Johannes Weiner 
Cc: Kirill A. Shutemov 
Cc: Michal Hocko 
Cc: Naoya Horiguchi 
Cc: Vlastimil Babka 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: make try_to_munlock() return void

2017-05-03T22:52:10+00:00

try_to_munlock returns SWAP_MLOCK if the one of VMAs mapped the page has
VM_LOCKED flag.  In that time, VM set PG_mlocked to the page if the page
is not pte-mapped THP which cannot be mlocked, either.

With that, __munlock_isolated_page can use PageMlocked to check whether
try_to_munlock is successful or not without relying on try_to_munlock's
retval.  It helps to make try_to_unmap/try_to_unmap_one simple with
upcoming patches.

[minchan@kernel.org: remove PG_Mlocked VM_BUG_ON check]
  Link: http://lkml.kernel.org/r/20170411025615.GA6545@bbox
Link: http://lkml.kernel.org/r/1489555493-14659-5-git-send-email-minchan@kernel.org
Signed-off-by: Minchan Kim 
Acked-by: Kirill A. Shutemov 
Acked-by: Vlastimil Babka 
Cc: Anshuman Khandual 
Cc: Hillf Danton 
Cc: Johannes Weiner 
Cc: Michal Hocko 
Cc: Naoya Horiguchi 
Cc: Sasha Levin 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: remove SWAP_DIRTY in ttu

2017-05-03T22:52:10+00:00

If we found lazyfree page is dirty, try_to_unmap_one can just
SetPageSwapBakced in there like PG_mlocked page and just return with
SWAP_FAIL which is very natural because the page is not swappable right
now so that vmscan can activate it.  There is no point to introduce new
return value SWAP_DIRTY in try_to_unmap at the moment.

Link: http://lkml.kernel.org/r/1489555493-14659-3-git-send-email-minchan@kernel.org
Signed-off-by: Minchan Kim 
Acked-by: Hillf Danton 
Acked-by: Kirill A. Shutemov 
Cc: Anshuman Khandual 
Cc: Johannes Weiner 
Cc: Michal Hocko 
Cc: Naoya Horiguchi 
Cc: Vlastimil Babka 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: reclaim MADV_FREE pages

2017-05-03T22:52:08+00:00

When memory pressure is high, we free MADV_FREE pages.  If the pages are
not dirty in pte, the pages could be freed immediately.  Otherwise we
can't reclaim them.  We put the pages back to anonumous LRU list (by
setting SwapBacked flag) and the pages will be reclaimed in normal
swapout way.

We use normal page reclaim policy.  Since MADV_FREE pages are put into
inactive file list, such pages and inactive file pages are reclaimed
according to their age.  This is expected, because we don't want to
reclaim too many MADV_FREE pages before used once pages.

Based on Minchan's original patch

[minchan@kernel.org: clean up lazyfree page handling]
  Link: http://lkml.kernel.org/r/20170303025237.GB3503@bbox
Link: http://lkml.kernel.org/r/14b8eb1d3f6bf6cc492833f183ac8c304e560484.1487965799.git.shli@fb.com
Signed-off-by: Shaohua Li 
Signed-off-by: Minchan Kim 
Acked-by: Minchan Kim 
Acked-by: Michal Hocko 
Acked-by: Johannes Weiner 
Acked-by: Hillf Danton 
Cc: Hugh Dickins 
Cc: Rik van Riel 
Cc: Mel Gorman 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds