linux-stable.git/mm/memblock.c, branch linux-3.3.y

memblock: memblock should be able to handle zero length operations

2012-04-27T17:16:34+00:00

commit b3dc627cabb33fc95f93da78457770c1b2a364d2 upstream.

Commit 24aa07882b ("memblock, x86: Replace memblock_x86_reserve/
free_range() with generic ones") replaced x86 specific memblock
operations with the generic ones; unfortunately, it lost zero length
operation handling in the process making the kernel panic if somebody
tries to reserve zero length area.

There isn't much to be gained by being cranky to zero length operations
and panicking is almost the worst response.  Drop the BUG_ON() in
memblock_reserve() and update memblock_add_region/isolate_range() so
that all zero length operations are handled as noops.

Signed-off-by: Tejun Heo 
Reported-by: Valere Monseur 
Bisected-by: Joseph Freeman 
Tested-by: Joseph Freeman 
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=43098
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

memblock: Fix size aligning of memblock_alloc_base_nid()

2012-03-01T09:53:18+00:00

memblock allocator aligns @size to @align to reduce the amount
of fragmentation.  Commit:

 7bd0b0f0da ("memblock: Reimplement memblock allocation using reverse free area iterator")

Broke it by incorrectly relocating @size aligning to
memblock_find_in_range_node().  As the aligned size is not
propagated back to memblock_alloc_base_nid(), the actually
reserved size isn't aligned.

While this increases memory use for memblock reserved array,
this shouldn't cause any critical failure; however, it seems
that the size aligning was hiding a use-beyond-allocation bug in
sparc64 and losing the aligning causes boot failure.

The underlying problem is currently being debugged but this is a
proper fix in itself, it's already pretty late in -rc cycle for
boot failures and reverting the change for debugging isn't
difficult. Restore the size aligning moving it to
memblock_alloc_base_nid().

Reported-by: Meelis Roos 
Signed-off-by: Tejun Heo 
Cc: David S. Miller 
Cc: Grant Likely 
Cc: Rob Herring 
Cc: Linus Torvalds 
Cc: Andrew Morton 
Link: http://lkml.kernel.org/r/20120228205621.GC3252@dhcp-172-17-108-109.mtv.corp.google.com
Signed-off-by: Ingo Molnar 
LKML-Reference:

memblock: Fix alloc failure due to dumb underflow protection in memblock_find_in_range_node()

2012-01-16T07:38:06+00:00

7bd0b0f0da ("memblock: Reimplement memblock allocation using
reverse free area iterator") implemented a simple top-down
allocator using a reverse memblock iterator.  To avoid underflow
in the allocator loop, it simply raised the lower boundary to
the requested size under the assumption that requested size
would be far smaller than available memblocks.

This causes early page table allocation failure under certain
configurations in Xen.  Fix it by checking for underflow directly
instead of bumping up lower bound.

Signed-off-by: Tejun Heo 
Reported-by: Konrad Rzeszutek Wilk 
Cc: rjw@sisk.pl
Cc: xen-devel@lists.xensource.com
Cc: Benjamin Herrenschmidt 
Cc: Andrew Morton 
Cc: Linus Torvalds 
Link: http://lkml.kernel.org/r/20120113181412.GA11112@google.com
Signed-off-by: Ingo Molnar

memblock: Reimplement memblock allocation using reverse free area iterator

2011-12-08T18:22:09+00:00

Now that all early memory information is in memblock when enabled, we
can implement reverse free area iterator and use it to implement NUMA
aware allocator which is then wrapped for simpler variants instead of
the confusing and inefficient mending of information in separate NUMA
aware allocator.

Implement for_each_free_mem_range_reverse(), use it to reimplement
memblock_find_in_range_node() which in turn is used by all allocators.

The visible allocator interface is inconsistent and can probably use
some cleanup too.

Signed-off-by: Tejun Heo 
Cc: Benjamin Herrenschmidt 
Cc: Yinghai Lu

memblock: Kill early_node_map[]

2011-12-08T18:22:09+00:00

Now all ARCH_POPULATES_NODE_MAP archs select HAVE_MEBLOCK_NODE_MAP -
there's no user of early_node_map[] left.  Kill early_node_map[] and
replace ARCH_POPULATES_NODE_MAP with HAVE_MEMBLOCK_NODE_MAP.  Also,
relocate for_each_mem_pfn_range() and helper from mm.h to memblock.h
as page_alloc.c would no longer host an alternative implementation.

This change is ultimately one to one mapping and shouldn't cause any
observable difference; however, after the recent changes, there are
some functions which now would fit memblock.c better than page_alloc.c
and dependency on HAVE_MEMBLOCK_NODE_MAP instead of HAVE_MEMBLOCK
doesn't make much sense on some of them.  Further cleanups for
functions inside HAVE_MEMBLOCK_NODE_MAP in mm.h would be nice.

-v2: Fix compile bug introduced by mis-spelling
 CONFIG_HAVE_MEMBLOCK_NODE_MAP to CONFIG_MEMBLOCK_HAVE_NODE_MAP in
 mmzone.h.  Reported by Stephen Rothwell.

Signed-off-by: Tejun Heo 
Cc: Stephen Rothwell 
Cc: Benjamin Herrenschmidt 
Cc: Yinghai Lu 
Cc: Tony Luck 
Cc: Ralf Baechle 
Cc: Martin Schwidefsky 
Cc: Chen Liqin 
Cc: Paul Mundt 
Cc: "David S. Miller" 
Cc: "H. Peter Anvin"

memblock: Implement memblock_add_node()

2011-12-08T18:22:08+00:00

Implement memblock_add_node() which can add a new memblock memory
region with specific node ID.

Signed-off-by: Tejun Heo 
Cc: Benjamin Herrenschmidt 
Cc: Yinghai Lu

memblock: s/memblock_analyze()/memblock_allow_resize()/ and update users

2011-12-08T18:22:08+00:00

The only function of memblock_analyze() is now allowing resize of
memblock region arrays.  Rename it to memblock_allow_resize() and
update its users.

* The following users remain the same other than renaming.

  arm/mm/init.c::arm_memblock_init()
  microblaze/kernel/prom.c::early_init_devtree()
  powerpc/kernel/prom.c::early_init_devtree()
  openrisc/kernel/prom.c::early_init_devtree()
  sh/mm/init.c::paging_init()
  sparc/mm/init_64.c::paging_init()
  unicore32/mm/init.c::uc32_memblock_init()

* In the following users, analyze was used to update total size which
  is no longer necessary.

  powerpc/kernel/machine_kexec.c::reserve_crashkernel()
  powerpc/kernel/prom.c::early_init_devtree()
  powerpc/mm/init_32.c::MMU_init()
  powerpc/mm/tlb_nohash.c::__early_init_mmu()  
  powerpc/platforms/ps3/mm.c::ps3_mm_add_memory()
  powerpc/platforms/embedded6xx/wii.c::wii_memory_fixups()
  sh/kernel/machine_kexec.c::reserve_crashkernel()

* x86/kernel/e820.c::memblock_x86_fill() was directly setting
  memblock_can_resize before populating memblock and calling analyze
  afterwards.  Call memblock_allow_resize() before start populating.

memblock_can_resize is now static inside memblock.c.

Signed-off-by: Tejun Heo 
Cc: Benjamin Herrenschmidt 
Cc: Yinghai Lu 
Cc: Russell King 
Cc: Michal Simek 
Cc: Paul Mundt 
Cc: "David S. Miller" 
Cc: Guan Xuetao 
Cc: "H. Peter Anvin"

memblock: Track total size of regions automatically

2011-12-08T18:22:08+00:00

Total size of memory regions was calculated by memblock_analyze()
requiring explicitly calling the function between operations which can
change memory regions and possible users of total size, which is
cumbersome and fragile.

This patch makes each memblock_type track total size automatically
with minor modifications to memblock manipulation functions and remove
requirements on calling memblock_analyze().  [__]memblock_dump_all()
now also dumps the total size of reserved regions.

Signed-off-by: Tejun Heo 
Cc: Benjamin Herrenschmidt 
Cc: Yinghai Lu

memblock: Reimplement memblock_enforce_memory_limit() using __memblock_remove()

2011-12-08T18:22:07+00:00

With recent updates, the basic memblock operations are robust enough
that there's no reason for memblock_enfore_memory_limit() to directly
manipulate memblock region arrays.  Reimplement it using
__memblock_remove().

Signed-off-by: Tejun Heo 
Cc: Benjamin Herrenschmidt 
Cc: Yinghai Lu

memblock: Make memblock functions handle overflowing range @size

2011-12-08T18:22:07+00:00

Allow memblock users to specify range where @base + @size overflows
and automatically cap it at maximum.  This makes the interface more
robust and specifying till-the-end-of-memory easier.

Signed-off-by: Tejun Heo 
Cc: Benjamin Herrenschmidt 
Cc: Yinghai Lu