mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-12 02:16:39 +07:00
e30500557e
This patch makes the needlessly global "global_faults" static. Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
81 lines
2.1 KiB
C
81 lines
2.1 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>
|
|
|
|
static DEFINE_SPINLOCK(swap_token_lock);
|
|
struct mm_struct *swap_token_mm;
|
|
static unsigned int global_faults;
|
|
|
|
void grab_swap_token(void)
|
|
{
|
|
int current_interval;
|
|
|
|
global_faults++;
|
|
|
|
current_interval = global_faults - current->mm->faultstamp;
|
|
|
|
if (!spin_trylock(&swap_token_lock))
|
|
return;
|
|
|
|
/* First come first served */
|
|
if (swap_token_mm == NULL) {
|
|
current->mm->token_priority = current->mm->token_priority + 2;
|
|
swap_token_mm = current->mm;
|
|
goto out;
|
|
}
|
|
|
|
if (current->mm != swap_token_mm) {
|
|
if (current_interval < current->mm->last_interval)
|
|
current->mm->token_priority++;
|
|
else {
|
|
current->mm->token_priority--;
|
|
if (unlikely(current->mm->token_priority < 0))
|
|
current->mm->token_priority = 0;
|
|
}
|
|
/* Check if we deserve the token */
|
|
if (current->mm->token_priority >
|
|
swap_token_mm->token_priority) {
|
|
current->mm->token_priority += 2;
|
|
swap_token_mm = current->mm;
|
|
}
|
|
} else {
|
|
/* Token holder came in again! */
|
|
current->mm->token_priority += 2;
|
|
}
|
|
|
|
out:
|
|
current->mm->faultstamp = global_faults;
|
|
current->mm->last_interval = current_interval;
|
|
spin_unlock(&swap_token_lock);
|
|
return;
|
|
}
|
|
|
|
/* Called on process exit. */
|
|
void __put_swap_token(struct mm_struct *mm)
|
|
{
|
|
spin_lock(&swap_token_lock);
|
|
if (likely(mm == swap_token_mm))
|
|
swap_token_mm = NULL;
|
|
spin_unlock(&swap_token_lock);
|
|
}
|