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.c b/mm/percpu.c
index da997f9..6087384 100644
--- a/mm/percpu.c
+++ b/mm/percpu.c
@@ -709,7 +709,8 @@
static int warn_limit = 10;
struct pcpu_chunk *chunk;
const char *err;
- int slot, off, new_alloc;
+ int slot, off, new_alloc, cpu;
+ int page_start, page_end, rs, re;
unsigned long flags;
void __percpu *ptr;
@@ -802,17 +803,32 @@
area_found:
spin_unlock_irqrestore(&pcpu_lock, flags);
- /* populate, map and clear the area */
- if (pcpu_populate_chunk(chunk, off, size)) {
- spin_lock_irqsave(&pcpu_lock, flags);
- pcpu_free_area(chunk, off);
- err = "failed to populate";
- goto fail_unlock;
+ /* populate if not all pages are already there */
+ page_start = PFN_DOWN(off);
+ page_end = PFN_UP(off + size);
+
+ rs = page_start;
+ pcpu_next_pop(chunk, &rs, &re, page_end);
+
+ if (rs != page_start || re != page_end) {
+ WARN_ON(chunk->immutable);
+
+ if (pcpu_populate_chunk(chunk, off, size)) {
+ spin_lock_irqsave(&pcpu_lock, flags);
+ pcpu_free_area(chunk, off);
+ err = "failed to populate";
+ goto fail_unlock;
+ }
+
+ bitmap_set(chunk->populated, page_start, page_end - page_start);
}
mutex_unlock(&pcpu_alloc_mutex);
- /* return address relative to base address */
+ /* clear the areas and return address relative to base address */
+ for_each_possible_cpu(cpu)
+ memset((void *)pcpu_chunk_addr(chunk, cpu, 0) + off, 0, size);
+
ptr = __addr_to_pcpu_ptr(chunk->base_addr + off);
kmemleak_alloc_percpu(ptr, size);
return ptr;
@@ -903,7 +919,12 @@
spin_unlock_irq(&pcpu_lock);
list_for_each_entry_safe(chunk, next, &todo, list) {
- pcpu_depopulate_chunk(chunk, 0, pcpu_unit_size);
+ int rs = 0, re;
+
+ pcpu_next_unpop(chunk, &rs, &re, PFN_UP(pcpu_unit_size));
+ if (rs || re != PFN_UP(pcpu_unit_size))
+ pcpu_depopulate_chunk(chunk, 0, pcpu_unit_size);
+
pcpu_destroy_chunk(chunk);
}
