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author | Julia Lawall <julia@diku.dk> | 2008-12-01 14:15:41 -0800 |
---|---|---|
committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2008-12-14 12:05:03 +0000 |
commit | 6ce1b871db6a3ca69ed1e35956d89d3cacd7ba08 (patch) | |
tree | fa3a1d73cc601de707ec21dad485319d42f7bfb5 /arch/arm/mm | |
parent | d517cab1c7fc92178e11c7ded2548b06b273d293 (diff) | |
download | kernel_samsung_tuna-6ce1b871db6a3ca69ed1e35956d89d3cacd7ba08.zip kernel_samsung_tuna-6ce1b871db6a3ca69ed1e35956d89d3cacd7ba08.tar.gz kernel_samsung_tuna-6ce1b871db6a3ca69ed1e35956d89d3cacd7ba08.tar.bz2 |
[ARM] eliminate NULL test and memset after alloc_bootmem
As noted by Akinobu Mita in patch b1fceac2b9e04d278316b2faddf276015fc06e3b,
alloc_bootmem and related functions never return NULL and always return a
zeroed region of memory. Thus a NULL test or memset after calls to these
functions is unnecessary.
This was fixed using the following semantic patch.
(http://www.emn.fr/x-info/coccinelle/)
// <smpl>
@@
expression E;
statement S;
@@
E = \(alloc_bootmem\|alloc_bootmem_low\|alloc_bootmem_pages\|alloc_bootmem_low_pages\|alloc_bootmem_node\|alloc_bootmem_low_pages_node\|alloc_bootmem_pages_node\)(...)
... when != E
(
- BUG_ON (E == NULL);
|
- if (E == NULL) S
)
@@
expression E,E1;
@@
E = \(alloc_bootmem\|alloc_bootmem_low\|alloc_bootmem_pages\|alloc_bootmem_low_pages\|alloc_bootmem_node\|alloc_bootmem_low_pages_node\|alloc_bootmem_pages_node\)(...)
... when != E
- memset(E,0,E1);
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/mm')
-rw-r--r-- | arch/arm/mm/mmu.c | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c index 2ab5f96..9b36c5c 100644 --- a/arch/arm/mm/mmu.c +++ b/arch/arm/mm/mmu.c @@ -827,7 +827,6 @@ static void __init devicemaps_init(struct machine_desc *mdesc) * Allocate the vector page early. */ vectors = alloc_bootmem_low_pages(PAGE_SIZE); - BUG_ON(!vectors); for (addr = VMALLOC_END; addr; addr += PGDIR_SIZE) pmd_clear(pmd_off_k(addr)); @@ -912,10 +911,10 @@ void __init paging_init(struct machine_desc *mdesc) top_pmd = pmd_off_k(0xffff0000); /* - * allocate the zero page. Note that we count on this going ok. + * allocate the zero page. Note that this always succeeds and + * returns a zeroed result. */ zero_page = alloc_bootmem_low_pages(PAGE_SIZE); - memset(zero_page, 0, PAGE_SIZE); empty_zero_page = virt_to_page(zero_page); flush_dcache_page(empty_zero_page); } |