145 lines
3.3 KiB
C
145 lines
3.3 KiB
C
/*
|
|
* mm/thrash.c
|
|
*
|
|
* Copyright (C) 2004, Red Hat, Inc.
|
|
* Copyright (C) 2004, Rik van Riel <riel@redhat.com>
|
|
* Released under the GPL, see the file COPYING for details.
|
|
*
|
|
* Simple token based thrashing protection, using the algorithm
|
|
* described in: http://www.cs.wm.edu/~sjiang/token.pdf
|
|
*
|
|
* Sep 2006, Ashwin Chaugule <ashwin.chaugule@celunite.com>
|
|
* Improved algorithm to pass token:
|
|
* Each task has a priority which is incremented if it contended
|
|
* for the token in an interval less than its previous attempt.
|
|
* If the token is acquired, that task's priority is boosted to prevent
|
|
* the token from bouncing around too often and to let the task make
|
|
* some progress in its execution.
|
|
*/
|
|
|
|
#include <linux/jiffies.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/swap.h>
|
|
#include <linux/memcontrol.h>
|
|
|
|
#include <trace/events/vmscan.h>
|
|
|
|
#define TOKEN_AGING_INTERVAL (0xFF)
|
|
|
|
static DEFINE_SPINLOCK(swap_token_lock);
|
|
struct mm_struct *swap_token_mm;
|
|
struct mem_cgroup *swap_token_memcg;
|
|
static unsigned int global_faults;
|
|
static unsigned int last_aging;
|
|
|
|
#ifdef CONFIG_CGROUP_MEM_RES_CTLR
|
|
static struct mem_cgroup *swap_token_memcg_from_mm(struct mm_struct *mm)
|
|
{
|
|
struct mem_cgroup *memcg;
|
|
|
|
memcg = try_get_mem_cgroup_from_mm(mm);
|
|
if (memcg)
|
|
css_put(mem_cgroup_css(memcg));
|
|
|
|
return memcg;
|
|
}
|
|
#else
|
|
static struct mem_cgroup *swap_token_memcg_from_mm(struct mm_struct *mm)
|
|
{
|
|
return NULL;
|
|
}
|
|
#endif
|
|
|
|
void grab_swap_token(struct mm_struct *mm)
|
|
{
|
|
int current_interval;
|
|
unsigned int old_prio = mm->token_priority;
|
|
|
|
global_faults++;
|
|
|
|
current_interval = global_faults - mm->faultstamp;
|
|
|
|
if (!spin_trylock(&swap_token_lock))
|
|
return;
|
|
|
|
/* First come first served */
|
|
if (!swap_token_mm)
|
|
goto replace_token;
|
|
|
|
if ((global_faults - last_aging) > TOKEN_AGING_INTERVAL) {
|
|
swap_token_mm->token_priority /= 2;
|
|
last_aging = global_faults;
|
|
}
|
|
|
|
if (mm == swap_token_mm) {
|
|
mm->token_priority += 2;
|
|
goto update_priority;
|
|
}
|
|
|
|
if (current_interval < mm->last_interval)
|
|
mm->token_priority++;
|
|
else {
|
|
if (likely(mm->token_priority > 0))
|
|
mm->token_priority--;
|
|
}
|
|
|
|
/* Check if we deserve the token */
|
|
if (mm->token_priority > swap_token_mm->token_priority)
|
|
goto replace_token;
|
|
|
|
update_priority:
|
|
trace_update_swap_token_priority(mm, old_prio, swap_token_mm);
|
|
|
|
out:
|
|
mm->faultstamp = global_faults;
|
|
mm->last_interval = current_interval;
|
|
spin_unlock(&swap_token_lock);
|
|
return;
|
|
|
|
replace_token:
|
|
mm->token_priority += 2;
|
|
trace_replace_swap_token(swap_token_mm, mm);
|
|
swap_token_mm = mm;
|
|
swap_token_memcg = swap_token_memcg_from_mm(mm);
|
|
last_aging = global_faults;
|
|
goto out;
|
|
}
|
|
|
|
/* Called on process exit. */
|
|
void __put_swap_token(struct mm_struct *mm)
|
|
{
|
|
spin_lock(&swap_token_lock);
|
|
if (likely(mm == swap_token_mm)) {
|
|
trace_put_swap_token(swap_token_mm);
|
|
swap_token_mm = NULL;
|
|
swap_token_memcg = NULL;
|
|
}
|
|
spin_unlock(&swap_token_lock);
|
|
}
|
|
|
|
static bool match_memcg(struct mem_cgroup *a, struct mem_cgroup *b)
|
|
{
|
|
if (!a)
|
|
return true;
|
|
if (!b)
|
|
return true;
|
|
if (a == b)
|
|
return true;
|
|
return false;
|
|
}
|
|
|
|
void disable_swap_token(struct mem_cgroup *memcg)
|
|
{
|
|
/* memcg reclaim don't disable unrelated mm token. */
|
|
if (match_memcg(memcg, swap_token_memcg)) {
|
|
spin_lock(&swap_token_lock);
|
|
if (match_memcg(memcg, swap_token_memcg)) {
|
|
trace_disable_swap_token(swap_token_mm);
|
|
swap_token_mm = NULL;
|
|
swap_token_memcg = NULL;
|
|
}
|
|
spin_unlock(&swap_token_lock);
|
|
}
|
|
}
|