[PATCH 07/20] percpu: make @dyn_size mandatory for pcpu_setup_first_chunk()

Tejun Heo
2009-07-21T10:28:10Z

Now that all actual first chunk allocation and copying happen in the
first chunk allocators and helpers, there's no reason for
pcpu_setup_first_chunk() to try to determine @dyn_size automatically.
The only left user is page first chunk allocator. Make it determine
dyn_size like other allocators and make @dyn_size mandatory for
pcpu_setup_first_chunk().

Signed-off-by: Tejun Heo <tj@kernel.org>
---
include/linux/percpu.h | 2 +-
mm/percpu.c | 39 +++++++++++++++++++--------------------
2 files changed, 20 insertions(+), 21 deletions(-)

diff --git a/include/linux/percpu.h b/include/linux/percpu.h
index be2fc8f..0cfdd14 100644
--- a/include/linux/percpu.h
+++ b/include/linux/percpu.h
@@ -79,7 +79,7 @@ typedef void (*pcpu_fc_map_fn_t)(void *ptr, size_t size, void *addr);

extern size_t __init pcpu_setup_first_chunk(
size_t static_size, size_t reserved_size,
- ssize_t dyn_size, size_t unit_size,
+ size_t dyn_size, size_t unit_size,
void *base_addr, const int *unit_map);

#ifdef CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK
diff --git a/mm/percpu.c b/mm/percpu.c
index e9f45ab..3177cf6 100644
--- a/mm/percpu.c
+++ b/mm/percpu.c
@@ -1235,7 +1235,7 @@ EXPORT_SYMBOL_GPL(free_percpu);
* pcpu_setup_first_chunk - initialize the first percpu chunk
* @static_size: the size of static percpu area in bytes
* @reserved_size: the size of reserved percpu area in bytes, 0 for none
- * @dyn_size: free size for dynamic allocation in bytes, -1 for auto
+ * @dyn_size: free size for dynamic allocation in bytes
* @unit_size: unit size in bytes, must be multiple of PAGE_SIZE
* @base_addr: mapped address
* @unit_map: cpu -> unit map, NULL for sequential mapping
@@ -1252,10 +1252,9 @@ 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.
+ * @dyn_size determines the number of bytes available for dynamic
+ * allocation in the first chunk. The area between @static_size +
+ * @reserved_size + @dyn_size and @unit_size is unused.
*
* @unit_size specifies unit size and must be aligned to PAGE_SIZE and
* equal to or larger than @static_size + @reserved_size + if
@@ -1276,13 +1275,12 @@ EXPORT_SYMBOL_GPL(free_percpu);
* percpu access.
*/
size_t __init pcpu_setup_first_chunk(size_t static_size, size_t reserved_size,
- ssize_t dyn_size, size_t unit_size,
+ size_t dyn_size, size_t unit_size,
void *base_addr, const int *unit_map)
{
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);
+ size_t size_sum = static_size + reserved_size + dyn_size;
struct pcpu_chunk *schunk, *dchunk = NULL;
unsigned int cpu, tcpu;
int i;
@@ -1345,9 +1343,6 @@ size_t __init pcpu_setup_first_chunk(size_t static_size, size_t reserved_size,
pcpu_chunk_struct_size = sizeof(struct pcpu_chunk) +
BITS_TO_LONGS(pcpu_unit_pages) * sizeof(unsigned long);

- if (dyn_size < 0)
- dyn_size = pcpu_unit_size - static_size - reserved_size;
-
first_vm.flags = VM_ALLOC;
first_vm.size = pcpu_chunk_size;
first_vm.addr = base_addr;
@@ -1557,6 +1552,8 @@ ssize_t __init pcpu_page_first_chunk(size_t reserved_size,
{
static struct vm_struct vm;
const size_t static_size = __per_cpu_end - __per_cpu_start;
+ ssize_t dyn_size = -1;
+ size_t size_sum, unit_size;
char psize_str[16];
int unit_pages;
size_t pages_size;
@@ -1567,8 +1564,9 @@ ssize_t __init pcpu_page_first_chunk(size_t reserved_size,

snprintf(psize_str, sizeof(psize_str), "%luK", PAGE_SIZE >> 10);

- unit_pages = PFN_UP(max_t(size_t, static_size + reserved_size,
- PCPU_MIN_UNIT_SIZE));
+ size_sum = pcpu_calc_fc_sizes(static_size, reserved_size, &dyn_size);
+ unit_size = max_t(size_t, size_sum, PCPU_MIN_UNIT_SIZE);
+ unit_pages = unit_size >> PAGE_SHIFT;

/* unaligned allocations can't be freed, round up to page size */
pages_size = PFN_ALIGN(unit_pages * nr_cpu_ids * sizeof(pages[0]));
@@ -1591,12 +1589,12 @@ ssize_t __init pcpu_page_first_chunk(size_t reserved_size,

/* allocate vm area, map the pages and copy static data */
vm.flags = VM_ALLOC;
- vm.size = nr_cpu_ids * unit_pages << PAGE_SHIFT;
+ vm.size = nr_cpu_ids * unit_size;
vm_area_register_early(&vm, PAGE_SIZE);

for_each_possible_cpu(cpu) {
- unsigned long unit_addr = (unsigned long)vm.addr +
- (cpu * unit_pages << PAGE_SHIFT);
+ unsigned long unit_addr =
+ (unsigned long)vm.addr + cpu * unit_size;

for (i = 0; i < unit_pages; i++)
populate_pte_fn(unit_addr + (i << PAGE_SHIFT));
@@ -1620,11 +1618,12 @@ ssize_t __init pcpu_page_first_chunk(size_t reserved_size,
}

/* we're ready, commit */
- pr_info("PERCPU: %d %s pages/cpu @%p s%zu r%zu\n",
- unit_pages, psize_str, vm.addr, static_size, reserved_size);
+ pr_info("PERCPU: %d %s pages/cpu @%p s%zu r%zu d%zu\n",
+ unit_pages, psize_str, vm.addr, static_size, reserved_size,
+ dyn_size);

- ret = pcpu_setup_first_chunk(static_size, reserved_size, -1,
- unit_pages << PAGE_SHIFT, vm.addr, NULL);
+ ret = pcpu_setup_first_chunk(static_size, reserved_size, dyn_size,
+ unit_size, vm.addr, NULL);
goto out_free_ar;

enomem:
--
1.6.0.2