From: Andi Kleen <a...@linux.intel.com> This one place in ggc forgot to round page_entry->bytes to the next page boundary, which lead to all the heuristics in freeing to check for continuous memory failing. Round here too, like all other allocators already do. The memory consumed should be the same for MMAP because the kernel would round anyways. It may slightly increase memory usage when malloc groups are used.
This will also increase the hitrate on the free page list slightly. gcc/: 2011-10-18 Andi Kleen <a...@linux.intel.com> * ggc-page.c (alloc_pages): Always round up entry_size. --- gcc/ggc-page.c | 1 + 1 files changed, 1 insertions(+), 0 deletions(-) diff --git a/gcc/ggc-page.c b/gcc/ggc-page.c index 2da99db..ba88e3f 100644 --- a/gcc/ggc-page.c +++ b/gcc/ggc-page.c @@ -736,6 +736,7 @@ alloc_page (unsigned order) entry_size = num_objects * OBJECT_SIZE (order); if (entry_size < G.pagesize) entry_size = G.pagesize; + entry_size = ROUND_UP (entry_size, G.pagesize); entry = NULL; page = NULL; -- 1.7.5.4