diff options
Diffstat (limited to 'mm/thrash.c')
| -rw-r--r-- | mm/thrash.c | 106 |
1 files changed, 0 insertions, 106 deletions
diff --git a/mm/thrash.c b/mm/thrash.c deleted file mode 100644 index f4c560b4a2b..00000000000 --- a/mm/thrash.c +++ /dev/null @@ -1,106 +0,0 @@ -/* - * 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 - */ -#include <linux/jiffies.h> -#include <linux/mm.h> -#include <linux/sched.h> -#include <linux/swap.h> - -static DEFINE_SPINLOCK(swap_token_lock); -static unsigned long swap_token_timeout; -static unsigned long swap_token_check; -struct mm_struct * swap_token_mm = &init_mm; - -#define SWAP_TOKEN_CHECK_INTERVAL (HZ * 2) -#define SWAP_TOKEN_TIMEOUT (300 * HZ) -/* - * Currently disabled; Needs further code to work at HZ * 300. - */ -unsigned long swap_token_default_timeout = SWAP_TOKEN_TIMEOUT; - -/* - * Take the token away if the process had no page faults - * in the last interval, or if it has held the token for - * too long. - */ -#define SWAP_TOKEN_ENOUGH_RSS 1 -#define SWAP_TOKEN_TIMED_OUT 2 -static int should_release_swap_token(struct mm_struct *mm) -{ - int ret = 0; - if (!mm->recent_pagein) - ret = SWAP_TOKEN_ENOUGH_RSS; - else if (time_after(jiffies, swap_token_timeout)) - ret = SWAP_TOKEN_TIMED_OUT; - mm->recent_pagein = 0; - return ret; -} - -/* - * Try to grab the swapout protection token. We only try to - * grab it once every TOKEN_CHECK_INTERVAL, both to prevent - * SMP lock contention and to check that the process that held - * the token before is no longer thrashing. - */ -void grab_swap_token(void) -{ - struct mm_struct *mm; - int reason; - - /* We have the token. Let others know we still need it. */ - if (has_swap_token(current->mm)) { - current->mm->recent_pagein = 1; - if (unlikely(!swap_token_default_timeout)) - disable_swap_token(); - return; - } - - if (time_after(jiffies, swap_token_check)) { - - if (!swap_token_default_timeout) { - swap_token_check = jiffies + SWAP_TOKEN_CHECK_INTERVAL; - return; - } - - /* ... or if we recently held the token. */ - if (time_before(jiffies, current->mm->swap_token_time)) - return; - - if (!spin_trylock(&swap_token_lock)) - return; - - swap_token_check = jiffies + SWAP_TOKEN_CHECK_INTERVAL; - - mm = swap_token_mm; - if ((reason = should_release_swap_token(mm))) { - unsigned long eligible = jiffies; - if (reason == SWAP_TOKEN_TIMED_OUT) { - eligible += swap_token_default_timeout; - } - mm->swap_token_time = eligible; - swap_token_timeout = jiffies + swap_token_default_timeout; - swap_token_mm = current->mm; - } - 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)) { - mm->swap_token_time = jiffies + SWAP_TOKEN_CHECK_INTERVAL; - swap_token_mm = &init_mm; - swap_token_check = jiffies; - } - spin_unlock(&swap_token_lock); -} |
