From 6074d5b0a319fe8400ff079a3c289406ca024321 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Tue, 10 Mar 2009 16:27:48 +0900 Subject: percpu: more flexibility for @dyn_size of pcpu_setup_first_chunk() Impact: cleanup, more flexibility for first chunk init Non-negative @dyn_size used to be allowed iff @unit_size wasn't auto. This restriction stemmed from implementation detail and made things a bit less intuitive. This patch allows @dyn_size to be specified regardless of @unit_size and swaps the positions of @dyn_size and @unit_size so that the parameter order makes more sense (static, reserved and dyn sizes followed by enclosing unit_size). While at it, add @unit_size >= PCPU_MIN_UNIT_SIZE sanity check. Signed-off-by: Tejun Heo --- mm/percpu.c | 28 ++++++++++++++-------------- 1 file changed, 14 insertions(+), 14 deletions(-) (limited to 'mm/percpu.c') diff --git a/mm/percpu.c b/mm/percpu.c index c6f38a2aface..2f94661d3e36 100644 --- a/mm/percpu.c +++ b/mm/percpu.c @@ -1027,8 +1027,8 @@ EXPORT_SYMBOL_GPL(free_percpu); * @get_page_fn: callback to fetch page pointer * @static_size: the size of static percpu area in bytes * @reserved_size: the size of reserved percpu area in bytes - * @unit_size: unit size in bytes, must be multiple of PAGE_SIZE, -1 for auto * @dyn_size: free size for dynamic allocation in bytes, -1 for auto + * @unit_size: unit size in bytes, must be multiple of PAGE_SIZE, -1 for auto * @base_addr: mapped address, NULL for auto * @populate_pte_fn: callback to allocate pagetable, NULL if unnecessary * @@ -1053,14 +1053,14 @@ EXPORT_SYMBOL_GPL(free_percpu); * limited offset range for symbol relocations to guarantee module * percpu symbols fall inside the relocatable range. * + * @dyn_size, if non-negative, determines the number of bytes + * available for dynamic allocation in the first chunk. Specifying + * non-negative value makes percpu leave alone the area beyond + * @static_size + @reserved_size + @dyn_size. + * * @unit_size, if non-negative, specifies unit size and must be * aligned to PAGE_SIZE and equal to or larger than @static_size + - * @reserved_size + @dyn_size. - * - * @dyn_size, if non-negative, limits the number of bytes available - * for dynamic allocation in the first chunk. Specifying non-negative - * value make percpu leave alone the area beyond @static_size + - * @reserved_size + @dyn_size. + * @reserved_size + if non-negative, @dyn_size. * * Non-null @base_addr means that the caller already allocated virtual * region for the first chunk and mapped it. percpu must not mess @@ -1083,12 +1083,14 @@ EXPORT_SYMBOL_GPL(free_percpu); */ size_t __init pcpu_setup_first_chunk(pcpu_get_page_fn_t get_page_fn, size_t static_size, size_t reserved_size, - ssize_t unit_size, ssize_t dyn_size, + ssize_t dyn_size, ssize_t unit_size, void *base_addr, pcpu_populate_pte_fn_t populate_pte_fn) { static struct vm_struct first_vm; static int smap[2], dmap[2]; + size_t size_sum = static_size + reserved_size + + (dyn_size >= 0 ? dyn_size : 0); struct pcpu_chunk *schunk, *dchunk = NULL; unsigned int cpu; int nr_pages; @@ -1099,20 +1101,18 @@ size_t __init pcpu_setup_first_chunk(pcpu_get_page_fn_t get_page_fn, ARRAY_SIZE(dmap) >= PCPU_DFL_MAP_ALLOC); BUG_ON(!static_size); if (unit_size >= 0) { - BUG_ON(unit_size < static_size + reserved_size + - (dyn_size >= 0 ? dyn_size : 0)); + BUG_ON(unit_size < size_sum); BUG_ON(unit_size & ~PAGE_MASK); - } else { - BUG_ON(dyn_size >= 0); + BUG_ON(unit_size < PCPU_MIN_UNIT_SIZE); + } else BUG_ON(base_addr); - } BUG_ON(base_addr && populate_pte_fn); if (unit_size >= 0) pcpu_unit_pages = unit_size >> PAGE_SHIFT; else pcpu_unit_pages = max_t(int, PCPU_MIN_UNIT_SIZE >> PAGE_SHIFT, - PFN_UP(static_size + reserved_size)); + PFN_UP(size_sum)); pcpu_unit_size = pcpu_unit_pages << PAGE_SHIFT; pcpu_chunk_size = num_possible_cpus() * pcpu_unit_size; -- cgit v1.2.3-59-g8ed1b