Hi Tejun,

On 12/04/2013 01:24 AM, Tejun Heo wrote:

Hello,

On Mon, Dec 02, 2013 at 09:27:23PM -0500, Santosh Shilimkar wrote:

quoted

So we add equivalent APIs so that we can replace usage of bootmem
with memblock interfaces. Architectures already converted to NO_BOOTMEM
use these new interfaces and other which still uses bootmem, these new
APIs just fallback to exiting bootmem APIs. So no functional change as
such.

The last part of the second last sentence doesn't parse too well.  I
think it'd be worthwhile to improve and preferably expand on it as
this is a bit tricky to understand given the twisted state of early
memory allocation.

quoted

In long run, once all the achitectures moves to NO_BOOTMEM, we can get rid of
bootmem layer completely. This is one step to remove the core code dependency
with bootmem and also gives path for architectures to move away from bootmem.

Lines too long?

[...]

quoted

+/* FIXME: Move to memblock.h at a point where we remove nobootmem.c */
+void *memblock_virt_alloc_try_nid_nopanic(phys_addr_t size,
+		phys_addr_t align, phys_addr_t from,
+		phys_addr_t max_addr, int nid);

Wouldn't @min_addr instead of @from make more sense?  Ditto for other
occurrences.

quoted

+void *memblock_virt_alloc_try_nid(phys_addr_t size, phys_addr_t align,
+		phys_addr_t from, phys_addr_t max_addr, int nid);
+void __memblock_free_early(phys_addr_t base, phys_addr_t size);
+void __memblock_free_late(phys_addr_t base, phys_addr_t size);
+
+#define memblock_virt_alloc(x) \
+	memblock_virt_alloc_try_nid(x, SMP_CACHE_BYTES, BOOTMEM_LOW_LIMIT, \
+				     BOOTMEM_ALLOC_ACCESSIBLE, MAX_NUMNODES)

The underlying function interprets 0 as the default align, so it
probably is a better idea to just use 0 here.

quoted

+#define memblock_virt_alloc_align(x, align) \
+	memblock_virt_alloc_try_nid(x, align, BOOTMEM_LOW_LIMIT, \
+				     BOOTMEM_ALLOC_ACCESSIBLE, MAX_NUMNODES)

Also, do we really need this align variant separate when the caller
can simply specify 0 for the default?

Unfortunately Yes. 
We need it to keep compatibility with bootmem/nobootmem
which don't handle 0 as default align value.

quoted

+#define memblock_virt_alloc_nopanic(x) \
+	memblock_virt_alloc_try_nid_nopanic(x, SMP_CACHE_BYTES, \
+					     BOOTMEM_LOW_LIMIT, \
+					     BOOTMEM_ALLOC_ACCESSIBLE, \
+					     MAX_NUMNODES)
+#define memblock_virt_alloc_align_nopanic(x, align) \
+	memblock_virt_alloc_try_nid_nopanic(x, align, \
+					     BOOTMEM_LOW_LIMIT, \
+					     BOOTMEM_ALLOC_ACCESSIBLE, \
+					     MAX_NUMNODES)
+#define memblock_virt_alloc_node(x, nid) \
+	memblock_virt_alloc_try_nid(x, SMP_CACHE_BYTES, BOOTMEM_LOW_LIMIT, \
+				     BOOTMEM_ALLOC_ACCESSIBLE, nid)
+#define memblock_virt_alloc_node_nopanic(x, nid) \

Regards,
- grygorii