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authorDave Chinner <dchinner@redhat.com>2013-08-28 10:18:11 +1000
committerAl Viro <viro@zeniv.linux.org.uk>2013-09-10 18:56:32 -0400
commit7dc19d5affd71370754a2c3d36b485810eaee7a1 (patch)
tree56b84fb2f7462e81c8340dea6341c30ce247f798 /drivers/staging
parent1ab6c4997e04a00c50c6d786c2f046adc0d1f5de (diff)
drivers: convert shrinkers to new count/scan API
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> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'drivers/staging')
-rw-r--r--drivers/staging/android/ashmem.c43
-rw-r--r--drivers/staging/android/lowmemorykiller.c43
2 files changed, 53 insertions, 33 deletions
diff --git a/drivers/staging/android/ashmem.c b/drivers/staging/android/ashmem.c
index 65f36d728714..8e76ddca0999 100644
--- a/drivers/staging/android/ashmem.c
+++ b/drivers/staging/android/ashmem.c
@@ -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 unsigned long
+ashmem_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
{
struct ashmem_range *range, *next;
+ unsigned 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 unsigned 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;
}
diff --git a/drivers/staging/android/lowmemorykiller.c b/drivers/staging/android/lowmemorykiller.c
index fe74494868ef..6f094b37f1f1 100644
--- a/drivers/staging/android/lowmemorykiller.c
+++ b/drivers/staging/android/lowmemorykiller.c
@@ -66,11 +66,20 @@ static unsigned long lowmem_deathpending_timeout;
pr_info(x); \
} while (0)
-static int lowmem_shrink(struct shrinker *s, struct shrink_control *sc)
+static unsigned 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 unsigned long lowmem_scan(struct shrinker *s, struct shrink_control *sc)
{
struct task_struct *tsk;
struct task_struct *selected = NULL;
- int rem = 0;
+ unsigned long rem = 0;
int tasksize;
int i;
short min_score_adj = OOM_SCORE_ADJ_MAX + 1;
@@ -92,19 +101,17 @@ 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 +161,18 @@ 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 %lu\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
};