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authorTejun Heo <tj@kernel.org>2010-04-09 18:57:01 +0900
committerTejun Heo <tj@kernel.org>2010-05-01 08:30:50 +0200
commitb0c9778b1d07ed3aa7e411db201275553527b1b1 (patch)
tree8649c1b27edebc6addef5087eb1830fc8bccdb74 /mm/percpu.c
parent9f6455325618821dcf6775d7972881fde32e77c5 (diff)
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percpu: implement kernel memory based chunk allocation
Implement an alternate percpu chunk management based on kernel memeory for nommu SMP architectures. Instead of mapping into vmalloc area, chunks are allocated as a contiguous kernel memory using alloc_pages(). As such, percpu allocator on nommu will have the following restrictions. * It can't fill chunks on-demand page-by-page. It has to allocate each chunk fully upfront. * It can't support sparse chunk for NUMA configurations. SMP w/o mmu is crazy enough. Let's hope no one does NUMA w/o mmu. :-P * If chunk size isn't power-of-two multiple of PAGE_SIZE, the unaligned amount will be wasted on each chunk. So, archs which use this better align chunk size. For instructions on how to use this, read the comment on top of mm/percpu-km.c. Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-by: David Howells <dhowells@redhat.com> Cc: Graff Yang <graff.yang@gmail.com> Cc: Sonic Zhang <sonic.adi@gmail.com>
Diffstat (limited to 'mm/percpu.c')
-rw-r--r--mm/percpu.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/mm/percpu.c b/mm/percpu.c
index 15f680430671..39f7dfd59585 100644
--- a/mm/percpu.c
+++ b/mm/percpu.c
@@ -654,7 +654,11 @@ static void pcpu_destroy_chunk(struct pcpu_chunk *chunk);
static struct page *pcpu_addr_to_page(void *addr);
static int __init pcpu_verify_alloc_info(const struct pcpu_alloc_info *ai);
+#ifdef CONFIG_NEED_PER_CPU_KM
+#include "percpu-km.c"
+#else
#include "percpu-vm.c"
+#endif
/**
* pcpu_chunk_addr_search - determine chunk containing specified address