linux.git/mm/bootmem.c, branch v3.5

bootmem: make ___alloc_bootmem_node_nopanic() really nopanic

2012-07-17T23:21:29+00:00

In reaction to commit 99ab7b19440a ("mm: sparse: fix usemap allocation
above node descriptor section") Johannes said:
| while backporting the below patch, I realised that your fix busted
| f5bf18fa22f8 again.  The problem was not a panicking version on
| allocation failure but when the usemap size was too large such that
| goal + size > limit triggers the BUG_ON in the bootmem allocator.  So
| we need a version that passes limit ONLY if the usemap is smaller than
| the section.

after checking the code, the name of ___alloc_bootmem_node_nopanic()
does not reflect the fact.

Make bootmem really not panic.

Hope will kill bootmem sooner.

Signed-off-by: Yinghai Lu 
Cc: Johannes Weiner 
Cc:     [3.3.x, 3.4.x]
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: sparse: fix usemap allocation above node descriptor section

2012-07-11T23:04:49+00:00

After commit f5bf18fa22f8 ("bootmem/sparsemem: remove limit constraint
in alloc_bootmem_section"), usemap allocations may easily be placed
outside the optimal section that holds the node descriptor, even if
there is space available in that section.  This results in unnecessary
hotplug dependencies that need to have the node unplugged before the
section holding the usemap.

The reason is that the bootmem allocator doesn't guarantee a linear
search starting from the passed allocation goal but may start out at a
much higher address absent an upper limit.

Fix this by trying the allocation with the limit at the section end,
then retry without if that fails.  This keeps the fix from f5bf18fa22f8
of not panicking if the allocation does not fit in the section, but
still makes sure to try to stay within the section at first.

Signed-off-by: Yinghai Lu 
Signed-off-by: Johannes Weiner 
Cc: 	[3.3.x, 3.4.x]
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm/bootmem.c: cleanup on addition to bootmem data list

2012-05-29T23:22:24+00:00

The objects of "struct bootmem_data_t" are linked together to form
double-linked list sequentially based on its minimal page frame number.

The current implementation implicitly supports the following cases,
which means the inserting point for current bootmem data depends on how
"list_for_each" works.  That makes the code a little hard to read.
Besides, "list_for_each" and "list_entry" can be replaced with
"list_for_each_entry".

        - The linked list is empty.
        - There has no entry in the linked list, whose minimal page
          frame number is bigger than current one.

Signed-off-by: Gavin Shan 
Acked-by: Johannes Weiner 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: remove sparsemem allocation details from the bootmem allocator

2012-05-29T23:22:22+00:00

alloc_bootmem_section() derives allocation area constraints from the
specified sparsemem section.  This is a bit specific for a generic memory
allocator like bootmem, though, so move it over to sparsemem.

As __alloc_bootmem_node_nopanic() already retries failed allocations with
relaxed area constraints, the fallback code in sparsemem.c can be removed
and the code becomes a bit more compact overall.

[akpm@linux-foundation.org: fix build]
Signed-off-by: Johannes Weiner 
Acked-by: Tejun Heo 
Acked-by: David S. Miller 
Cc: Yinghai Lu 
Cc: Gavin Shan 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: bootmem: pass pgdat instead of pgdat->bdata down the stack

2012-05-29T23:22:22+00:00

Pass down the node descriptor instead of the more specific bootmem node
descriptor down the call stack, like nobootmem does, when there is no good
reason for the two to be different.

Signed-off-by: Johannes Weiner 
Acked-by: Tejun Heo 
Acked-by: David S. Miller 
Cc: Yinghai Lu 
Cc: Gavin Shan 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: bootmem: unify allocation policy of (non-)panicking node allocations

2012-05-29T23:22:22+00:00

While the panicking node-specific allocation function tries to satisfy
node+goal, goal, node, anywhere, the non-panicking function still does
node+goal, goal, anywhere.

Make it simpler: define the panicking version in terms of the
non-panicking one, like the node-agnostic interface, so they always behave
the same way apart from how to deal with allocation failure.

Signed-off-by: Johannes Weiner 
Acked-by: Tejun Heo 
Acked-by: David S. Miller 
Cc: Yinghai Lu 
Cc: Gavin Shan 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: bootmem: allocate in order node+goal, goal, node, anywhere

2012-05-29T23:22:21+00:00

Match the nobootmem version of __alloc_bootmem_node.  Try to satisfy both
the node and the goal, then just the goal, then just the node, then
allocate anywhere before panicking.

Signed-off-by: Johannes Weiner 
Acked-by: Tejun Heo 
Acked-by: David S. Miller 
Cc: Yinghai Lu 
Cc: Gavin Shan 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: bootmem: split out goal-to-node mapping from goal dropping

2012-05-29T23:22:21+00:00

Matching the desired goal to the right node is one thing, dropping the
goal when it can not be satisfied is another.  Split this into separate
functions so that subsequent patches can use the node-finding but drop and
handle the goal fallback on their own terms.

Signed-off-by: Johannes Weiner 
Acked-by: Tejun Heo 
Acked-by: David S. Miller 
Cc: Yinghai Lu 
Cc: Gavin Shan 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: bootmem: rename alloc_bootmem_core to alloc_bootmem_bdata

2012-05-29T23:22:21+00:00

Callsites need to provide a bootmem_data_t *, make the naming more
descriptive.

Signed-off-by: Johannes Weiner 
Acked-by: Tejun Heo 
Acked-by: David S. Miller 
Cc: Yinghai Lu 
Cc: Gavin Shan 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: bootmem: remove redundant offset check when finally freeing bootmem

2012-05-29T23:22:21+00:00

When bootmem releases an unaligned BITS_PER_LONG pages chunk of memory
to the page allocator, it checks the bitmap if there are still
unreserved pages in the chunk (set bits), but also if the offset in the
chunk indicates BITS_PER_LONG loop iterations already.

But since the consulted bitmap is only a one-word-excerpt of the full
per-node bitmap, there can not be more than BITS_PER_LONG bits set in
it.  The additional offset check is unnecessary.

Signed-off-by: Johannes Weiner 
Acked-by: Tejun Heo 
Acked-by: David S. Miller 
Cc: Yinghai Lu 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds