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percpu: move fully free chunk reclamation into a work 

Impact: code reorganization for later changes

Do fully free chunk reclamation using a work.  This change is to
prepare for locking changes.

Signed-off-by: Tejun Heo <tj@kernel.org>
hifive-unleashed-5.1
Tejun Heo 2009-03-07 00:44:11 +09:00
parent 9f7dcf224b
commit a56dbddf06
1 changed files with 38 additions and 10 deletions
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48
mm/percpu.c
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@ -63,6 +63,7 @@
#include <linux/rbtree.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/workqueue.h>
#include <asm/cacheflush.h>
#include <asm/tlbflush.h>
@ -118,6 +119,10 @@ static DEFINE_MUTEX(pcpu_mutex);
static struct list_head *pcpu_slot __read_mostly; /* chunk list slots */
static struct rb_root pcpu_addr_root = RB_ROOT; /* chunks by address */
/* reclaim work to release fully free chunks, scheduled from free path */
static void pcpu_reclaim(struct work_struct *work);
static DECLARE_WORK(pcpu_reclaim_work, pcpu_reclaim);
static int __pcpu_size_to_slot(int size)
{
int highbit = fls(size); /* size is in bytes */
@ -846,13 +851,37 @@ void *__alloc_reserved_percpu(size_t size, size_t align)
return pcpu_alloc(size, align, true);
}
static void pcpu_kill_chunk(struct pcpu_chunk *chunk)
/**
* pcpu_reclaim - reclaim fully free chunks, workqueue function
* @work: unused
*
* Reclaim all fully free chunks except for the first one.
*/
static void pcpu_reclaim(struct work_struct *work)
{
WARN_ON(chunk->immutable);
pcpu_depopulate_chunk(chunk, 0, pcpu_unit_size, false);
list_del(&chunk->list);
rb_erase(&chunk->rb_node, &pcpu_addr_root);
free_pcpu_chunk(chunk);
LIST_HEAD(todo);
struct list_head *head = &pcpu_slot[pcpu_nr_slots - 1];
struct pcpu_chunk *chunk, *next;
mutex_lock(&pcpu_mutex);
list_for_each_entry_safe(chunk, next, head, list) {
WARN_ON(chunk->immutable);
/* spare the first one */
if (chunk == list_first_entry(head, struct pcpu_chunk, list))
continue;
rb_erase(&chunk->rb_node, &pcpu_addr_root);
list_move(&chunk->list, &todo);
}
mutex_unlock(&pcpu_mutex);
list_for_each_entry_safe(chunk, next, &todo, list) {
pcpu_depopulate_chunk(chunk, 0, pcpu_unit_size, false);
free_pcpu_chunk(chunk);
}
}
/**
@ -877,14 +906,13 @@ void free_percpu(void *ptr)
pcpu_free_area(chunk, off);
/* the chunk became fully free, kill one if there are other free ones */
/* if there are more than one fully free chunks, wake up grim reaper */
if (chunk->free_size == pcpu_unit_size) {
struct pcpu_chunk *pos;
list_for_each_entry(pos,
&pcpu_slot[pcpu_chunk_slot(chunk)], list)
list_for_each_entry(pos, &pcpu_slot[pcpu_nr_slots - 1], list)
if (pos != chunk) {
pcpu_kill_chunk(pos);
schedule_work(&pcpu_reclaim_work);
break;
}
}