Re: [v6 04/15] mm: discard memblock data later

From: Pasha Tatashin
Date: Fri Aug 11 2017 - 15:02:21 EST


Hi Michal,

This suggestion won't work, because there are arches without memblock support: tile, sh...

So, I would still need to have:

#ifdef CONFIG_MEMBLOCK in page_alloc, or define memblock_discard() stubs in nobootmem headfile. In either case it would become messier than what it is right now.

Pasha

I have just one nit below
Acked-by: Michal Hocko <mhocko@xxxxxxxx>

[...]
diff --git a/mm/memblock.c b/mm/memblock.c
index 2cb25fe4452c..bf14aea6ab70 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -285,31 +285,27 @@ static void __init_memblock memblock_remove_region(struct memblock_type *type, u
}
#ifdef CONFIG_ARCH_DISCARD_MEMBLOCK

pull this ifdef inside memblock_discard and you do not have an another
one in page_alloc_init_late

[...]
+/**
+ * Discard memory and reserved arrays if they were allocated
+ */
+void __init memblock_discard(void)
{

here

- if (memblock.memory.regions == memblock_memory_init_regions)
- return 0;
+ phys_addr_t addr, size;
- *addr = __pa(memblock.memory.regions);
+ if (memblock.reserved.regions != memblock_reserved_init_regions) {
+ addr = __pa(memblock.reserved.regions);
+ size = PAGE_ALIGN(sizeof(struct memblock_region) *
+ memblock.reserved.max);
+ __memblock_free_late(addr, size);
+ }
- return PAGE_ALIGN(sizeof(struct memblock_region) *
- memblock.memory.max);
+ if (memblock.memory.regions == memblock_memory_init_regions) {
+ addr = __pa(memblock.memory.regions);
+ size = PAGE_ALIGN(sizeof(struct memblock_region) *
+ memblock.memory.max);
+ __memblock_free_late(addr, size);
+ }
}
-
#endif