Commit graph

5 commits

Author SHA1 Message Date
Peter Zijlstra
b945d6b255 rbtree: Undo augmented trees performance damage and regression
Reimplement augmented RB-trees without sprinkling extra branches
all over the RB-tree code (which lives in the scheduler hot path).

This approach is 'borrowed' from Fabio's BFQ implementation and
relies on traversing the rebalance path after the RB-tree-op to
correct the heap property for insertion/removal and make up for
the damage done by the tree rotations.

For insertion the rebalance path is trivially that from the new
node upwards to the root, for removal it is that from the deepest
node in the path from the to be removed node that will still
be around after the removal.

[ This patch also fixes a video driver regression reported by
  Ali Gholami Rudi - the memtype->subtree_max_end was updated
  incorrectly. ]

Acked-by: Suresh Siddha <suresh.b.siddha@intel.com>
Acked-by: Venkatesh Pallipadi <venki@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Tested-by: Ali Gholami Rudi <ali@rudi.ir>
Cc: Fabio Checconi <fabio@gandalf.sssup.it>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <1275414172.27810.27961.camel@twins>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-07-05 14:43:50 +02:00
Venkatesh Pallipadi
6a4f3b5237 x86, pat: Proper init of memtype subtree_max_end
subtree_max_end that was recently added to struct memtype was not getting
properly initialized resulting in

WARNING: kmemcheck: Caught 64-bit read from uninitialized memory
in memtype_rb_augment_cb()
reported here
https://bugzilla.kernel.org/show_bug.cgi?id=16092

This change fixes the problem.

Reported-by: Christian Casteyde <casteyde.christian@free.fr>
Tested-by: Christian Casteyde <casteyde.christian@free.fr>
Signed-off-by: Venkatesh Pallipadi <venki@google.com>
LKML-Reference: <1276217101-11515-1-git-send-email-venki@google.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
2010-06-11 14:12:22 -07:00
Xiaotian Feng
20413f2716 x86, pat: Fix memory leak in free_memtype
Reserve_memtype will allocate memory for new memtype, but
in free_memtype, after the memtype erased from rbtree, the
memory is not freed.

Changes since V1:
	make rbt_memtype_erase return erased memtype so that
	it can be freed in free_memtype.

[ hpa: not for -stable: 2.6.34 and earlier not affected ]

Signed-off-by: Xiaotian Feng <dfeng@redhat.com>
LKML-Reference: <1274838670-8731-1-git-send-email-dfeng@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: Jack Steiner <steiner@sgi.com>
Acked-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2010-05-26 11:26:04 -07:00
Pallipadi, Venkatesh
4daa2a8093 x86, pat: In rbt_memtype_check_insert(), update new->type only if valid
new->type should only change when there is a valid ret_type. Otherwise
the requested type and return type should be same.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
LKML-Reference: <20100224214355.GA16431@linux-os.sc.intel.com>
Tested-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2010-03-01 14:28:48 -08:00
Pallipadi, Venkatesh
9e41a49aab x86, pat: Migrate to rbtree only backend for pat memtype management
Move pat backend to fully rbtree based implementation from the existing
rbtree and linked list hybrid.

New rbtree based solution uses interval trees (augmented rbtrees) in
order to store the PAT ranges. The new code seprates out the pat backend
to pat_rbtree.c file, making is cleaner. The change also makes the PAT
lookup, reserve and free operations more optimal, as we don't have to
traverse linear linked list of few tens of entries in normal case.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
LKML-Reference: <20100210232607.GB11465@linux-os.sc.intel.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2010-02-18 15:41:36 -08:00