6 files changed, 2 insertions, 170 deletions

diff --git a/mm/Makefile b/mm/Makefile
index 8aada89efbbb..ccecbf9818f5 100644
--- a/mm/Makefile
+++ b/mm/Makefile
@@ -25,7 +25,7 @@ endif
 obj-$(CONFIG_HAVE_MEMBLOCK) += memblock.o
 
 obj-$(CONFIG_BOUNCE)    += bounce.o
-obj-$(CONFIG_SWAP)      += page_io.o swap_state.o swapfile.o thrash.o
+obj-$(CONFIG_SWAP)      += page_io.o swap_state.o swapfile.o
 obj-$(CONFIG_HAS_DMA)   += dmapool.o
 obj-$(CONFIG_HUGETLBFS) += hugetlb.o
 obj-$(CONFIG_NUMA)      += mempolicy.o
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index f342778a0c0a..92675fe8a2ef 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -5598,7 +5598,6 @@ static void mem_cgroup_move_task(struct cgroup *cont,
         if (mm) {
                 if (mc.to)
                         mem_cgroup_move_charge(mm);
-                put_swap_token(mm);
                 mmput(mm);
         }
         if (mc.to)
diff --git a/mm/memory.c b/mm/memory.c
index e40f6759ba98..2bf9e110437c 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -2908,7 +2908,6 @@ static int do_swap_page(struct mm_struct *mm, struct vm_area_struct *vma,
         delayacct_set_flag(DELAYACCT_PF_SWAPIN);
         page = lookup_swap_cache(entry);
         if (!page) {
-                grab_swap_token(mm); /* Contend for token _before_ read-in */
                 page = swapin_readahead(entry,
                                         GFP_HIGHUSER_MOVABLE, vma, address);
                 if (!page) {
@@ -2938,6 +2937,7 @@ static int do_swap_page(struct mm_struct *mm, struct vm_area_struct *vma,
         }
 
         locked = lock_page_or_retry(page, mm, flags);
+
         delayacct_clear_flag(DELAYACCT_PF_SWAPIN);
         if (!locked) {
                 ret |= VM_FAULT_RETRY;
diff --git a/mm/rmap.c b/mm/rmap.c
index 5b5ad584ffb7..0f3b7cda2a24 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -755,12 +755,6 @@ int page_referenced_one(struct page *page, struct vm_area_struct *vma,
                 pte_unmap_unlock(pte, ptl);
         }
 
-        /* Pretend the page is referenced if the task has the
-           swap token and is in the middle of a page fault. */
-        if (mm != current->mm && has_swap_token(mm) &&
-                        rwsem_is_locked(&mm->mmap_sem))
-                referenced++;
-
         (*mapcount)--;
 
         if (referenced)
diff --git a/mm/thrash.c b/mm/thrash.c
deleted file mode 100644
index 57ad495dbd54..000000000000
--- a/mm/thrash.c
+++ /dev/null
@@ -1,155 +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.cse.ohio-state.edu/hpcs/WWW/HTML/publications/abs05-1.html
- *
- * 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;
-static struct mem_cgroup *swap_token_memcg;
-
-#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;
-        static unsigned int global_faults;
-        static unsigned int last_aging;
-
-        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;
-
-        /*
-         * Usually, we don't need priority aging because long interval faults
-         * makes priority decrease quickly. But there is one exception. If the
-         * token owner task is sleeping, it never make long interval faults.
-         * Thus, we need a priority aging mechanism instead. The requirements
-         * of priority aging are
-         *  1) An aging interval is reasonable enough long. Too short aging
-         *     interval makes quick swap token lost and decrease performance.
-         *  2) The swap token owner task have to get priority aging even if
-         *     it's under sleep.
-         */
-        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);
-        }
-}
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 33dc256033b5..ca46080bb074 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -2352,8 +2352,6 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist,
 
         for (priority = DEF_PRIORITY; priority >= 0; priority--) {
                 sc->nr_scanned = 0;
-                if (!priority)
-                        disable_swap_token(sc->target_mem_cgroup);
                 aborted_reclaim = shrink_zones(priority, zonelist, sc);
 
                 /*
@@ -2704,10 +2702,6 @@ loop_again:
                 unsigned long lru_pages = 0;
                 int has_under_min_watermark_zone = 0;
 
-                /* The swap token gets in the way of swapout... */
-                if (!priority)
-                        disable_swap_token(NULL);
-
                 all_zones_ok = 1;
                 balanced = 0;