From e63075a3c9377536d085bc013cd3fe6323162449 Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Tue, 6 Jul 2010 15:39:01 -0700 Subject: memblock: Introduce default allocation limit and use it to replace explicit ones This introduce memblock.current_limit which is used to limit allocations from memblock_alloc() or memblock_alloc_base(..., MEMBLOCK_ALLOC_ACCESSIBLE). The old MEMBLOCK_ALLOC_ANYWHERE changes value from 0 to ~(u64)0 and can still be used with memblock_alloc_base() to allocate really anywhere. It is -no-longer- cropped to MEMBLOCK_REAL_LIMIT which disappears. Note to archs: I'm leaving the default limit to MEMBLOCK_ALLOC_ANYWHERE. I strongly recommend that you ensure that you set an appropriate limit during boot in order to guarantee that an memblock_alloc() at any time results in something that is accessible with a simple __va(). The reason is that a subsequent patch will introduce the ability for the array to resize itself by reallocating itself. The MEMBLOCK core will honor the current limit when performing those allocations. Signed-off-by: Benjamin Herrenschmidt --- mm/memblock.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) (limited to 'mm/memblock.c') diff --git a/mm/memblock.c b/mm/memblock.c index 0131684c42f..770c5bfac2c 100644 --- a/mm/memblock.c +++ b/mm/memblock.c @@ -115,6 +115,8 @@ void __init memblock_init(void) memblock.reserved.regions[0].base = 0; memblock.reserved.regions[0].size = 0; memblock.reserved.cnt = 1; + + memblock.current_limit = MEMBLOCK_ALLOC_ANYWHERE; } void __init memblock_analyze(void) @@ -373,7 +375,7 @@ u64 __init memblock_alloc_nid(u64 size, u64 align, int nid) u64 __init memblock_alloc(u64 size, u64 align) { - return memblock_alloc_base(size, align, MEMBLOCK_ALLOC_ANYWHERE); + return memblock_alloc_base(size, align, MEMBLOCK_ALLOC_ACCESSIBLE); } u64 __init memblock_alloc_base(u64 size, u64 align, u64 max_addr) @@ -399,14 +401,9 @@ u64 __init __memblock_alloc_base(u64 size, u64 align, u64 max_addr) size = memblock_align_up(size, align); - /* On some platforms, make sure we allocate lowmem */ - /* Note that MEMBLOCK_REAL_LIMIT may be MEMBLOCK_ALLOC_ANYWHERE */ - if (max_addr == MEMBLOCK_ALLOC_ANYWHERE) - max_addr = MEMBLOCK_REAL_LIMIT; - /* Pump up max_addr */ - if (max_addr == MEMBLOCK_ALLOC_ANYWHERE) - max_addr = ~(u64)0; + if (max_addr == MEMBLOCK_ALLOC_ACCESSIBLE) + max_addr = memblock.current_limit; /* We do a top-down search, this tends to limit memory * fragmentation by keeping early boot allocs near the @@ -527,3 +524,9 @@ int memblock_is_region_reserved(u64 base, u64 size) return memblock_overlaps_region(&memblock.reserved, base, size) >= 0; } + +void __init memblock_set_current_limit(u64 limit) +{ + memblock.current_limit = limit; +} + -- cgit v1.2.3