percpu: move common parts out of pcpu_[de]populate_chunk()
percpu-vm and percpu-km implement separate versions of
pcpu_[de]populate_chunk() and some part which is or should be common
are currently in the specific implementations. Make the following
changes.
* Allocate area clearing is moved from the pcpu_populate_chunk()
implementations to pcpu_alloc(). This makes percpu-km's version
noop.
* Quick exit tests in pcpu_[de]populate_chunk() of percpu-vm are moved
to their respective callers so that they are applied to percpu-km
too. This doesn't make any meaningful difference as both functions
are noop for percpu-km; however, this is more consistent and will
help implementing atomic allocation support.
Signed-off-by: Tejun Heo <tj@kernel.org>
diff --git a/mm/percpu-vm.c b/mm/percpu-vm.c
index d9e0b61..edf7097 100644
--- a/mm/percpu-vm.c
+++ b/mm/percpu-vm.c
@@ -265,7 +265,7 @@
* @size: size of the area to populate in bytes
*
* For each cpu, populate and map pages [@page_start,@page_end) into
- * @chunk. The area is cleared on return.
+ * @chunk.
*
* CONTEXT:
* pcpu_alloc_mutex, does GFP_KERNEL allocation.
@@ -276,18 +276,8 @@
int page_end = PFN_UP(off + size);
int free_end = page_start, unmap_end = page_start;
struct page **pages;
- unsigned int cpu;
int rs, re, rc;
- /* quick path, check whether all pages are already there */
- rs = page_start;
- pcpu_next_pop(chunk, &rs, &re, page_end);
- if (rs == page_start && re == page_end)
- goto clear;
-
- /* need to allocate and map pages, this chunk can't be immutable */
- WARN_ON(chunk->immutable);
-
pages = pcpu_get_pages(chunk);
if (!pages)
return -ENOMEM;
@@ -308,10 +298,6 @@
}
pcpu_post_map_flush(chunk, page_start, page_end);
- bitmap_set(chunk->populated, page_start, page_end - page_start);
-clear:
- for_each_possible_cpu(cpu)
- memset((void *)pcpu_chunk_addr(chunk, cpu, 0) + off, 0, size);
return 0;
err_unmap:
@@ -345,15 +331,6 @@
struct page **pages;
int rs, re;
- /* quick path, check whether it's empty already */
- rs = page_start;
- pcpu_next_unpop(chunk, &rs, &re, page_end);
- if (rs == page_start && re == page_end)
- return;
-
- /* immutable chunks can't be depopulated */
- WARN_ON(chunk->immutable);
-
/*
* If control reaches here, there must have been at least one
* successful population attempt so the temp pages array must
@@ -372,8 +349,6 @@
pcpu_for_each_pop_region(chunk, rs, re, page_start, page_end)
pcpu_free_pages(chunk, pages, rs, re);
-
- bitmap_clear(chunk->populated, page_start, page_end - page_start);
}
static struct pcpu_chunk *pcpu_create_chunk(void)