]> git.karo-electronics.de Git - karo-tx-linux.git/commitdiff
drivers: convert shrinkers to new count/scan API
authorDave Chinner <dchinner@redhat.com>
Thu, 1 Aug 2013 06:36:16 +0000 (16:36 +1000)
committerStephen Rothwell <sfr@canb.auug.org.au>
Mon, 5 Aug 2013 06:12:19 +0000 (16:12 +1000)
Convert the driver shrinkers to the new API.  Most changes are compile
tested only because I either don't have the hardware or it's staging
stuff.

FWIW, the md and android code is pretty good, but the rest of it makes me
want to claw my eyes out.  The amount of broken code I just encountered is
mind boggling.  I've added comments explaining what is broken, but I fear
that some of the code would be best dealt with by being dragged behind the
bike shed, burying in mud up to it's neck and then run over repeatedly
with a blunt lawn mower.

Special mention goes to the zcache/zcache2 drivers.  They can't co-exist
in the build at the same time, they are under different menu options in
menuconfig, they only show up when you've got the right set of mm
subsystem options configured and so even compile testing is an exercise in
pulling teeth.  And that doesn't even take into account the horrible,
broken code...

[glommer@openvz.org: fixes for i915, android lowmem, zcache, bcache]
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Glauber Costa <glommer@openvz.org>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Kent Overstreet <koverstreet@google.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Thomas Hellstrom <thellstrom@vmware.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Cc: Arve Hjønnevåg <arve@android.com>
Cc: Carlos Maiolino <cmaiolino@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: David Rientjes <rientjes@google.com>
Cc: Gleb Natapov <gleb@redhat.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: J. Bruce Fields <bfields@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Kent Overstreet <koverstreet@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Thomas Hellstrom <thellstrom@vmware.com>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
drivers/gpu/drm/i915/i915_dma.c
drivers/gpu/drm/i915/i915_gem.c
drivers/gpu/drm/ttm/ttm_page_alloc.c
drivers/gpu/drm/ttm/ttm_page_alloc_dma.c
drivers/md/bcache/btree.c
drivers/md/bcache/sysfs.c
drivers/md/dm-bufio.c
drivers/staging/android/ashmem.c
drivers/staging/android/lowmemorykiller.c
drivers/staging/zcache/zcache-main.c

index de611f64bb1668ecbf1001eeec5af8a8d945df5b..b8e15906f3fc0c6243db9f099b9f20dd026ac0bf 100644 (file)
@@ -1652,7 +1652,7 @@ int i915_driver_load(struct drm_device *dev, unsigned long flags)
        return 0;
 
 out_gem_unload:
-       if (dev_priv->mm.inactive_shrinker.shrink)
+       if (dev_priv->mm.inactive_shrinker.scan_objects)
                unregister_shrinker(&dev_priv->mm.inactive_shrinker);
 
        if (dev->pdev->msi_enabled)
@@ -1686,7 +1686,7 @@ int i915_driver_unload(struct drm_device *dev)
 
        i915_teardown_sysfs(dev);
 
-       if (dev_priv->mm.inactive_shrinker.shrink)
+       if (dev_priv->mm.inactive_shrinker.scan_objects)
                unregister_shrinker(&dev_priv->mm.inactive_shrinker);
 
        mutex_lock(&dev->struct_mutex);
index 3a5d4baa4c536b2cf285adc1ced00198992b3eca..49db617aab02f87d336b84b48e61637c87b4aacb 100644 (file)
@@ -54,10 +54,12 @@ static void i915_gem_object_update_fence(struct drm_i915_gem_object *obj,
                                         struct drm_i915_fence_reg *fence,
                                         bool enable);
 
-static int i915_gem_inactive_shrink(struct shrinker *shrinker,
+static long i915_gem_inactive_count(struct shrinker *shrinker,
                                    struct shrink_control *sc);
+static long i915_gem_inactive_scan(struct shrinker *shrinker,
+                                  struct shrink_control *sc);
 static long i915_gem_purge(struct drm_i915_private *dev_priv, long target);
-static void i915_gem_shrink_all(struct drm_i915_private *dev_priv);
+static long i915_gem_shrink_all(struct drm_i915_private *dev_priv);
 static void i915_gem_object_truncate(struct drm_i915_gem_object *obj);
 
 static inline void i915_gem_object_fence_lost(struct drm_i915_gem_object *obj)
@@ -1719,16 +1721,21 @@ i915_gem_purge(struct drm_i915_private *dev_priv, long target)
        return __i915_gem_shrink(dev_priv, target, true);
 }
 
-static void
+static long
 i915_gem_shrink_all(struct drm_i915_private *dev_priv)
 {
        struct drm_i915_gem_object *obj, *next;
+       long freed = 0;
 
        i915_gem_evict_everything(dev_priv->dev);
 
        list_for_each_entry_safe(obj, next, &dev_priv->mm.unbound_list,
-                                global_list)
+                                global_list) {
+               if (obj->pages_pin_count == 0)
+                       freed += obj->base.size >> PAGE_SHIFT;
                i915_gem_object_put_pages(obj);
+       }
+       return freed;
 }
 
 static int
@@ -4387,7 +4394,8 @@ i915_gem_load(struct drm_device *dev)
 
        dev_priv->mm.interruptible = true;
 
-       dev_priv->mm.inactive_shrinker.shrink = i915_gem_inactive_shrink;
+       dev_priv->mm.inactive_shrinker.scan_objects = i915_gem_inactive_scan;
+       dev_priv->mm.inactive_shrinker.count_objects = i915_gem_inactive_count;
        dev_priv->mm.inactive_shrinker.seeks = DEFAULT_SEEKS;
        register_shrinker(&dev_priv->mm.inactive_shrinker);
 }
@@ -4610,8 +4618,8 @@ static bool mutex_is_locked_by(struct mutex *mutex, struct task_struct *task)
 #endif
 }
 
-static int
-i915_gem_inactive_shrink(struct shrinker *shrinker, struct shrink_control *sc)
+static long
+i915_gem_inactive_count(struct shrinker *shrinker, struct shrink_control *sc)
 {
        struct drm_i915_private *dev_priv =
                container_of(shrinker,
@@ -4620,9 +4628,8 @@ i915_gem_inactive_shrink(struct shrinker *shrinker, struct shrink_control *sc)
        struct drm_device *dev = dev_priv->dev;
        struct i915_address_space *vm = &dev_priv->gtt.base;
        struct drm_i915_gem_object *obj;
-       int nr_to_scan = sc->nr_to_scan;
        bool unlock = true;
-       int cnt;
+       long cnt;
 
        if (!mutex_trylock(&dev->struct_mutex)) {
                if (!mutex_is_locked_by(&dev->struct_mutex, current))
@@ -4634,15 +4641,6 @@ i915_gem_inactive_shrink(struct shrinker *shrinker, struct shrink_control *sc)
                unlock = false;
        }
 
-       if (nr_to_scan) {
-               nr_to_scan -= i915_gem_purge(dev_priv, nr_to_scan);
-               if (nr_to_scan > 0)
-                       nr_to_scan -= __i915_gem_shrink(dev_priv, nr_to_scan,
-                                                       false);
-               if (nr_to_scan > 0)
-                       i915_gem_shrink_all(dev_priv);
-       }
-
        cnt = 0;
        list_for_each_entry(obj, &dev_priv->mm.unbound_list, global_list)
                if (obj->pages_pin_count == 0)
@@ -4655,3 +4653,36 @@ i915_gem_inactive_shrink(struct shrinker *shrinker, struct shrink_control *sc)
                mutex_unlock(&dev->struct_mutex);
        return cnt;
 }
+static long
+i915_gem_inactive_scan(struct shrinker *shrinker, struct shrink_control *sc)
+{
+       struct drm_i915_private *dev_priv =
+               container_of(shrinker,
+                            struct drm_i915_private,
+                            mm.inactive_shrinker);
+       struct drm_device *dev = dev_priv->dev;
+       int nr_to_scan = sc->nr_to_scan;
+       long freed;
+       bool unlock = true;
+
+       if (!mutex_trylock(&dev->struct_mutex)) {
+               if (!mutex_is_locked_by(&dev->struct_mutex, current))
+                       return 0;
+
+               if (dev_priv->mm.shrinker_no_lock_stealing)
+                       return 0;
+
+               unlock = false;
+       }
+
+       freed = i915_gem_purge(dev_priv, nr_to_scan);
+       if (freed < nr_to_scan)
+               freed += __i915_gem_shrink(dev_priv, nr_to_scan,
+                                                       false);
+       if (freed < nr_to_scan)
+               freed += i915_gem_shrink_all(dev_priv);
+
+       if (unlock)
+               mutex_unlock(&dev->struct_mutex);
+       return freed;
+}
index bd2a3b40cd129b30d4445a8cdca8adec2eb492f9..1746f30c6b63babcce79bc2e311df31597a75d9d 100644 (file)
@@ -377,28 +377,26 @@ out:
        return nr_free;
 }
 
-/* Get good estimation how many pages are free in pools */
-static int ttm_pool_get_num_unused_pages(void)
-{
-       unsigned i;
-       int total = 0;
-       for (i = 0; i < NUM_POOLS; ++i)
-               total += _manager->pools[i].npages;
-
-       return total;
-}
-
 /**
  * Callback for mm to request pool to reduce number of page held.
+ *
+ * XXX: (dchinner) Deadlock warning!
+ *
+ * ttm_page_pool_free() does memory allocation using GFP_KERNEL.  that means
+ * this can deadlock when called a sc->gfp_mask that is not equal to
+ * GFP_KERNEL.
+ *
+ * This code is crying out for a shrinker per pool....
  */
-static int ttm_pool_mm_shrink(struct shrinker *shrink,
-                             struct shrink_control *sc)
+static long
+ttm_pool_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
 {
        static atomic_t start_pool = ATOMIC_INIT(0);
        unsigned i;
        unsigned pool_offset = atomic_add_return(1, &start_pool);
        struct ttm_page_pool *pool;
        int shrink_pages = sc->nr_to_scan;
+       long freed = 0;
 
        pool_offset = pool_offset % NUM_POOLS;
        /* select start pool in round robin fashion */
@@ -408,14 +406,28 @@ static int ttm_pool_mm_shrink(struct shrinker *shrink,
                        break;
                pool = &_manager->pools[(i + pool_offset)%NUM_POOLS];
                shrink_pages = ttm_page_pool_free(pool, nr_free);
+               freed += nr_free - shrink_pages;
        }
-       /* return estimated number of unused pages in pool */
-       return ttm_pool_get_num_unused_pages();
+       return freed;
+}
+
+
+static long
+ttm_pool_shrink_count(struct shrinker *shrink, struct shrink_control *sc)
+{
+       unsigned i;
+       long count = 0;
+
+       for (i = 0; i < NUM_POOLS; ++i)
+               count += _manager->pools[i].npages;
+
+       return count;
 }
 
 static void ttm_pool_mm_shrink_init(struct ttm_pool_manager *manager)
 {
-       manager->mm_shrink.shrink = &ttm_pool_mm_shrink;
+       manager->mm_shrink.count_objects = &ttm_pool_shrink_count;
+       manager->mm_shrink.scan_objects = &ttm_pool_shrink_scan;
        manager->mm_shrink.seeks = 1;
        register_shrinker(&manager->mm_shrink);
 }
index b8b394319b45947facd37036817b73ac39a2661c..dc009f15af4270beaf635b5433a858f244b9cdfb 100644 (file)
@@ -918,19 +918,6 @@ int ttm_dma_populate(struct ttm_dma_tt *ttm_dma, struct device *dev)
 }
 EXPORT_SYMBOL_GPL(ttm_dma_populate);
 
-/* Get good estimation how many pages are free in pools */
-static int ttm_dma_pool_get_num_unused_pages(void)
-{
-       struct device_pools *p;
-       unsigned total = 0;
-
-       mutex_lock(&_manager->lock);
-       list_for_each_entry(p, &_manager->pools, pools)
-               total += p->pool->npages_free;
-       mutex_unlock(&_manager->lock);
-       return total;
-}
-
 /* Put all pages in pages list to correct pool to wait for reuse */
 void ttm_dma_unpopulate(struct ttm_dma_tt *ttm_dma, struct device *dev)
 {
@@ -1002,18 +989,29 @@ EXPORT_SYMBOL_GPL(ttm_dma_unpopulate);
 
 /**
  * Callback for mm to request pool to reduce number of page held.
+ *
+ * XXX: (dchinner) Deadlock warning!
+ *
+ * ttm_dma_page_pool_free() does GFP_KERNEL memory allocation, and so attention
+ * needs to be paid to sc->gfp_mask to determine if this can be done or not.
+ * GFP_KERNEL memory allocation in a GFP_ATOMIC reclaim context woul dbe really
+ * bad.
+ *
+ * I'm getting sadder as I hear more pathetical whimpers about needing per-pool
+ * shrinkers
  */
-static int ttm_dma_pool_mm_shrink(struct shrinker *shrink,
-                                 struct shrink_control *sc)
+static long
+ttm_dma_pool_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
 {
        static atomic_t start_pool = ATOMIC_INIT(0);
        unsigned idx = 0;
        unsigned pool_offset = atomic_add_return(1, &start_pool);
        unsigned shrink_pages = sc->nr_to_scan;
        struct device_pools *p;
+       long freed = 0;
 
        if (list_empty(&_manager->pools))
-               return 0;
+               return SHRINK_STOP;
 
        mutex_lock(&_manager->lock);
        pool_offset = pool_offset % _manager->npools;
@@ -1029,18 +1027,33 @@ static int ttm_dma_pool_mm_shrink(struct shrinker *shrink,
                        continue;
                nr_free = shrink_pages;
                shrink_pages = ttm_dma_page_pool_free(p->pool, nr_free);
+               freed += nr_free - shrink_pages;
+
                pr_debug("%s: (%s:%d) Asked to shrink %d, have %d more to go\n",
                         p->pool->dev_name, p->pool->name, current->pid,
                         nr_free, shrink_pages);
        }
        mutex_unlock(&_manager->lock);
-       /* return estimated number of unused pages in pool */
-       return ttm_dma_pool_get_num_unused_pages();
+       return freed;
+}
+
+static long
+ttm_dma_pool_shrink_count(struct shrinker *shrink, struct shrink_control *sc)
+{
+       struct device_pools *p;
+       long count = 0;
+
+       mutex_lock(&_manager->lock);
+       list_for_each_entry(p, &_manager->pools, pools)
+               count += p->pool->npages_free;
+       mutex_unlock(&_manager->lock);
+       return count;
 }
 
 static void ttm_dma_pool_mm_shrink_init(struct ttm_pool_manager *manager)
 {
-       manager->mm_shrink.shrink = &ttm_dma_pool_mm_shrink;
+       manager->mm_shrink.count_objects = &ttm_dma_pool_shrink_count;
+       manager->mm_shrink.scan_objects = &ttm_dma_pool_shrink_scan;
        manager->mm_shrink.seeks = 1;
        register_shrinker(&manager->mm_shrink);
 }
index ee372884c405444886671901e45c3834626f383a..6cdc11c14f313904b42c5d9c56c36b3b4ad2e423 100644 (file)
@@ -597,24 +597,18 @@ static int mca_reap(struct btree *b, struct closure *cl, unsigned min_order)
        return 0;
 }
 
-static int bch_mca_shrink(struct shrinker *shrink, struct shrink_control *sc)
+static long bch_mca_scan(struct shrinker *shrink, struct shrink_control *sc)
 {
        struct cache_set *c = container_of(shrink, struct cache_set, shrink);
        struct btree *b, *t;
        unsigned long i, nr = sc->nr_to_scan;
+       long freed = 0;
 
        if (c->shrinker_disabled)
-               return 0;
+               return SHRINK_STOP;
 
        if (c->try_harder)
-               return 0;
-
-       /*
-        * If nr == 0, we're supposed to return the number of items we have
-        * cached. Not allowed to return -1.
-        */
-       if (!nr)
-               return mca_can_free(c) * c->btree_pages;
+               return SHRINK_STOP;
 
        /* Return -1 if we can't do anything right now */
        if (sc->gfp_mask & __GFP_WAIT)
@@ -634,14 +628,14 @@ static int bch_mca_shrink(struct shrinker *shrink, struct shrink_control *sc)
 
        i = 0;
        list_for_each_entry_safe(b, t, &c->btree_cache_freeable, list) {
-               if (!nr)
+               if (freed >= nr)
                        break;
 
                if (++i > 3 &&
                    !mca_reap(b, NULL, 0)) {
                        mca_data_free(b);
                        rw_unlock(true, b);
-                       --nr;
+                       freed++;
                }
        }
 
@@ -652,7 +646,7 @@ static int bch_mca_shrink(struct shrinker *shrink, struct shrink_control *sc)
        if (list_empty(&c->btree_cache))
                goto out;
 
-       for (i = 0; nr && i < c->bucket_cache_used; i++) {
+       for (i = 0; (nr--) && i < c->bucket_cache_used; i++) {
                b = list_first_entry(&c->btree_cache, struct btree, list);
                list_rotate_left(&c->btree_cache);
 
@@ -661,14 +655,26 @@ static int bch_mca_shrink(struct shrinker *shrink, struct shrink_control *sc)
                        mca_bucket_free(b);
                        mca_data_free(b);
                        rw_unlock(true, b);
-                       --nr;
+                       freed++;
                } else
                        b->accessed = 0;
        }
 out:
-       nr = mca_can_free(c) * c->btree_pages;
        mutex_unlock(&c->bucket_lock);
-       return nr;
+       return freed;
+}
+
+static long bch_mca_count(struct shrinker *shrink, struct shrink_control *sc)
+{
+       struct cache_set *c = container_of(shrink, struct cache_set, shrink);
+
+       if (c->shrinker_disabled)
+               return 0;
+
+       if (c->try_harder)
+               return 0;
+
+       return mca_can_free(c) * c->btree_pages;
 }
 
 void bch_btree_cache_free(struct cache_set *c)
@@ -737,7 +743,8 @@ int bch_btree_cache_alloc(struct cache_set *c)
                c->verify_data = NULL;
 #endif
 
-       c->shrink.shrink = bch_mca_shrink;
+       c->shrink.count_objects = bch_mca_count;
+       c->shrink.scan_objects = bch_mca_scan;
        c->shrink.seeks = 4;
        c->shrink.batch = c->btree_pages * 2;
        register_shrinker(&c->shrink);
index 12a2c2846f994a1e2d51bf79374426df96893418..4fe6ab2fbe2ede59644441521aa4cc2f27f5d312 100644 (file)
@@ -556,7 +556,7 @@ STORE(__bch_cache_set)
                struct shrink_control sc;
                sc.gfp_mask = GFP_KERNEL;
                sc.nr_to_scan = strtoul_or_return(buf);
-               c->shrink.shrink(&c->shrink, &sc);
+               c->shrink.scan_objects(&c->shrink, &sc);
        }
 
        sysfs_strtoul(congested_read_threshold_us,
index 5227e079a6e3b27afd71bcbdc2d03fa01e211ceb..a2ee58991e70481096bdb78f3edddff91a0b4e4e 100644 (file)
@@ -1425,62 +1425,76 @@ static int __cleanup_old_buffer(struct dm_buffer *b, gfp_t gfp,
                                unsigned long max_jiffies)
 {
        if (jiffies - b->last_accessed < max_jiffies)
-               return 1;
+               return 0;
 
        if (!(gfp & __GFP_IO)) {
                if (test_bit(B_READING, &b->state) ||
                    test_bit(B_WRITING, &b->state) ||
                    test_bit(B_DIRTY, &b->state))
-                       return 1;
+                       return 0;
        }
 
        if (b->hold_count)
-               return 1;
+               return 0;
 
        __make_buffer_clean(b);
        __unlink_buffer(b);
        __free_buffer_wake(b);
 
-       return 0;
+       return 1;
 }
 
-static void __scan(struct dm_bufio_client *c, unsigned long nr_to_scan,
-                  struct shrink_control *sc)
+static long __scan(struct dm_bufio_client *c, unsigned long nr_to_scan,
+                  gfp_t gfp_mask)
 {
        int l;
        struct dm_buffer *b, *tmp;
+       long freed = 0;
 
        for (l = 0; l < LIST_SIZE; l++) {
-               list_for_each_entry_safe_reverse(b, tmp, &c->lru[l], lru_list)
-                       if (!__cleanup_old_buffer(b, sc->gfp_mask, 0) &&
-                           !--nr_to_scan)
-                               return;
+               list_for_each_entry_safe_reverse(b, tmp, &c->lru[l], lru_list) {
+                       freed += __cleanup_old_buffer(b, gfp_mask, 0);
+                       if (!--nr_to_scan)
+                               break;
+               }
                dm_bufio_cond_resched();
        }
+       return freed;
 }
 
-static int shrink(struct shrinker *shrinker, struct shrink_control *sc)
+static long
+dm_bufio_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
 {
        struct dm_bufio_client *c =
-           container_of(shrinker, struct dm_bufio_client, shrinker);
-       unsigned long r;
-       unsigned long nr_to_scan = sc->nr_to_scan;
+           container_of(shrink, struct dm_bufio_client, shrinker);
+       long freed;
 
        if (sc->gfp_mask & __GFP_IO)
                dm_bufio_lock(c);
        else if (!dm_bufio_trylock(c))
-               return !nr_to_scan ? 0 : -1;
+               return SHRINK_STOP;
 
-       if (nr_to_scan)
-               __scan(c, nr_to_scan, sc);
+       freed  = __scan(c, sc->nr_to_scan, sc->gfp_mask);
+       dm_bufio_unlock(c);
+       return freed;
+}
 
-       r = c->n_buffers[LIST_CLEAN] + c->n_buffers[LIST_DIRTY];
-       if (r > INT_MAX)
-               r = INT_MAX;
+static long
+dm_bufio_shrink_count(struct shrinker *shrink, struct shrink_control *sc)
+{
+       struct dm_bufio_client *c =
+           container_of(shrink, struct dm_bufio_client, shrinker);
+       long count;
+
+       if (sc->gfp_mask & __GFP_IO)
+               dm_bufio_lock(c);
+       else if (!dm_bufio_trylock(c))
+               return 0;
 
+       count = c->n_buffers[LIST_CLEAN] + c->n_buffers[LIST_DIRTY];
        dm_bufio_unlock(c);
+       return count;
 
-       return r;
 }
 
 /*
@@ -1582,7 +1596,8 @@ struct dm_bufio_client *dm_bufio_client_create(struct block_device *bdev, unsign
        __cache_size_refresh();
        mutex_unlock(&dm_bufio_clients_lock);
 
-       c->shrinker.shrink = shrink;
+       c->shrinker.count_objects = dm_bufio_shrink_count;
+       c->shrinker.scan_objects = dm_bufio_shrink_scan;
        c->shrinker.seeks = 1;
        c->shrinker.batch = 0;
        register_shrinker(&c->shrinker);
@@ -1669,7 +1684,7 @@ static void cleanup_old_buffers(void)
                        struct dm_buffer *b;
                        b = list_entry(c->lru[LIST_CLEAN].prev,
                                       struct dm_buffer, lru_list);
-                       if (__cleanup_old_buffer(b, 0, max_age * HZ))
+                       if (!__cleanup_old_buffer(b, 0, max_age * HZ))
                                break;
                        dm_bufio_cond_resched();
                }
index 65f36d7287149a799c88207fcc1566134b6ea8d7..9b5186b800ec7224db011c479c89f5d993699cc5 100644 (file)
@@ -341,27 +341,26 @@ out:
 /*
  * ashmem_shrink - our cache shrinker, called from mm/vmscan.c :: shrink_slab
  *
- * 'nr_to_scan' is the number of objects (pages) to prune, or 0 to query how
- * many objects (pages) we have in total.
+ * 'nr_to_scan' is the number of objects to scan for freeing.
  *
  * 'gfp_mask' is the mask of the allocation that got us into this mess.
  *
- * Return value is the number of objects (pages) remaining, or -1 if we cannot
+ * Return value is the number of objects freed or -1 if we cannot
  * proceed without risk of deadlock (due to gfp_mask).
  *
  * We approximate LRU via least-recently-unpinned, jettisoning unpinned partial
  * chunks of ashmem regions LRU-wise one-at-a-time until we hit 'nr_to_scan'
  * pages freed.
  */
-static int ashmem_shrink(struct shrinker *s, struct shrink_control *sc)
+static long
+ashmem_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
 {
        struct ashmem_range *range, *next;
+       long freed = 0;
 
        /* We might recurse into filesystem code, so bail out if necessary */
-       if (sc->nr_to_scan && !(sc->gfp_mask & __GFP_FS))
-               return -1;
-       if (!sc->nr_to_scan)
-               return lru_count;
+       if (!(sc->gfp_mask & __GFP_FS))
+               return SHRINK_STOP;
 
        mutex_lock(&ashmem_mutex);
        list_for_each_entry_safe(range, next, &ashmem_lru_list, lru) {
@@ -374,17 +373,32 @@ static int ashmem_shrink(struct shrinker *s, struct shrink_control *sc)
                range->purged = ASHMEM_WAS_PURGED;
                lru_del(range);
 
-               sc->nr_to_scan -= range_size(range);
-               if (sc->nr_to_scan <= 0)
+               freed += range_size(range);
+               if (--sc->nr_to_scan <= 0)
                        break;
        }
        mutex_unlock(&ashmem_mutex);
+       return freed;
+}
 
+static long
+ashmem_shrink_count(struct shrinker *shrink, struct shrink_control *sc)
+{
+       /*
+        * note that lru_count is count of pages on the lru, not a count of
+        * objects on the list. This means the scan function needs to return the
+        * number of pages freed, not the number of objects scanned.
+        */
        return lru_count;
 }
 
 static struct shrinker ashmem_shrinker = {
-       .shrink = ashmem_shrink,
+       .count_objects = ashmem_shrink_count,
+       .scan_objects = ashmem_shrink_scan,
+       /*
+        * XXX (dchinner): I wish people would comment on why they need on
+        * significant changes to the default value here
+        */
        .seeks = DEFAULT_SEEKS * 4,
 };
 
@@ -690,14 +704,11 @@ static long ashmem_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
                if (capable(CAP_SYS_ADMIN)) {
                        struct shrink_control sc = {
                                .gfp_mask = GFP_KERNEL,
-                               .nr_to_scan = 0,
+                               .nr_to_scan = LONG_MAX,
                        };
 
                        nodes_setall(sc.nodes_to_scan);
-
-                       ret = ashmem_shrink(&ashmem_shrinker, &sc);
-                       sc.nr_to_scan = ret;
-                       ashmem_shrink(&ashmem_shrinker, &sc);
+                       ashmem_shrink_scan(&ashmem_shrinker, &sc);
                }
                break;
        }
index fe74494868ef33037e7e43602471b51780f6c37d..d23bfeabdcbd7dd9e5454d4ab296913391d538a4 100644 (file)
@@ -66,7 +66,15 @@ static unsigned long lowmem_deathpending_timeout;
                        pr_info(x);                     \
        } while (0)
 
-static int lowmem_shrink(struct shrinker *s, struct shrink_control *sc)
+static long lowmem_count(struct shrinker *s, struct shrink_control *sc)
+{
+       return global_page_state(NR_ACTIVE_ANON) +
+               global_page_state(NR_ACTIVE_FILE) +
+               global_page_state(NR_INACTIVE_ANON) +
+               global_page_state(NR_INACTIVE_FILE);
+}
+
+static long lowmem_scan(struct shrinker *s, struct shrink_control *sc)
 {
        struct task_struct *tsk;
        struct task_struct *selected = NULL;
@@ -92,19 +100,17 @@ static int lowmem_shrink(struct shrinker *s, struct shrink_control *sc)
                        break;
                }
        }
-       if (sc->nr_to_scan > 0)
-               lowmem_print(3, "lowmem_shrink %lu, %x, ofree %d %d, ma %hd\n",
-                               sc->nr_to_scan, sc->gfp_mask, other_free,
-                               other_file, min_score_adj);
-       rem = global_page_state(NR_ACTIVE_ANON) +
-               global_page_state(NR_ACTIVE_FILE) +
-               global_page_state(NR_INACTIVE_ANON) +
-               global_page_state(NR_INACTIVE_FILE);
-       if (sc->nr_to_scan <= 0 || min_score_adj == OOM_SCORE_ADJ_MAX + 1) {
-               lowmem_print(5, "lowmem_shrink %lu, %x, return %d\n",
-                            sc->nr_to_scan, sc->gfp_mask, rem);
-               return rem;
+
+       lowmem_print(3, "lowmem_scan %lu, %x, ofree %d %d, ma %hd\n",
+                       sc->nr_to_scan, sc->gfp_mask, other_free,
+                       other_file, min_score_adj);
+
+       if (min_score_adj == OOM_SCORE_ADJ_MAX + 1) {
+               lowmem_print(5, "lowmem_scan %lu, %x, return 0\n",
+                            sc->nr_to_scan, sc->gfp_mask);
+               return 0;
        }
+
        selected_oom_score_adj = min_score_adj;
 
        rcu_read_lock();
@@ -154,16 +160,18 @@ static int lowmem_shrink(struct shrinker *s, struct shrink_control *sc)
                lowmem_deathpending_timeout = jiffies + HZ;
                send_sig(SIGKILL, selected, 0);
                set_tsk_thread_flag(selected, TIF_MEMDIE);
-               rem -= selected_tasksize;
+               rem += selected_tasksize;
        }
-       lowmem_print(4, "lowmem_shrink %lu, %x, return %d\n",
+
+       lowmem_print(4, "lowmem_scan %lu, %x, return %d\n",
                     sc->nr_to_scan, sc->gfp_mask, rem);
        rcu_read_unlock();
        return rem;
 }
 
 static struct shrinker lowmem_shrinker = {
-       .shrink = lowmem_shrink,
+       .scan_objects = lowmem_scan,
+       .count_objects = lowmem_count,
        .seeks = DEFAULT_SEEKS * 16
 };
 
index f8bbce00fb1f227e0c53dade7358eaecc7e4e7ea..cba7f006db6c2224aaccc90495618365e4f3153f 100644 (file)
@@ -1140,23 +1140,19 @@ static bool zcache_freeze;
  * pageframes in use.  FIXME POLICY: Probably the writeback should only occur
  * if the eviction doesn't free enough pages.
  */
-static int shrink_zcache_memory(struct shrinker *shrink,
-                               struct shrink_control *sc)
+static long scan_zcache_memory(struct shrinker *shrink,
+                              struct shrink_control *sc)
 {
        static bool in_progress;
-       int ret = -1;
-       int nr = sc->nr_to_scan;
        int nr_evict = 0;
        int nr_writeback = 0;
        struct page *page;
        int  file_pageframes_inuse, anon_pageframes_inuse;
-
-       if (nr <= 0)
-               goto skip_evict;
+       long freed = 0;
 
        /* don't allow more than one eviction thread at a time */
        if (in_progress)
-               goto skip_evict;
+               return 0;
 
        in_progress = true;
 
@@ -1176,6 +1172,7 @@ static int shrink_zcache_memory(struct shrinker *shrink,
                if (page == NULL)
                        break;
                zcache_free_page(page);
+               freed++;
        }
 
        zcache_last_active_anon_pageframes =
@@ -1192,13 +1189,22 @@ static int shrink_zcache_memory(struct shrinker *shrink,
 #ifdef CONFIG_ZCACHE_WRITEBACK
                int writeback_ret;
                writeback_ret = zcache_frontswap_writeback();
-               if (writeback_ret == -ENOMEM)
+               if (writeback_ret != -ENOMEM)
+                       freed++;
+               else
 #endif
                        break;
        }
        in_progress = false;
 
-skip_evict:
+       return freed;
+}
+
+static long count_zcache_memory(struct shrinker *shrink,
+                               struct shrink_control *sc)
+{
+       int ret = -1;
+
        /* resample: has changed, but maybe not all the way yet */
        zcache_last_active_file_pageframes =
                global_page_state(NR_LRU_BASE + LRU_ACTIVE_FILE);
@@ -1212,7 +1218,8 @@ skip_evict:
 }
 
 static struct shrinker zcache_shrinker = {
-       .shrink = shrink_zcache_memory,
+       .scan_objects = scan_zcache_memory,
+       .count_objects = count_zcache_memory,
        .seeks = DEFAULT_SEEKS,
 };