[PATCHv2 4/6] mm/zpool: zbud/zsmalloc implement zpool

From: Dan Streetman
Date: Mon Jun 02 2014 - 18:20:41 EST


Update zbud and zsmalloc to implement the zpool api.

Signed-off-by: Dan Streetman <ddstreet@xxxxxxxx>
Cc: Seth Jennings <sjennings@xxxxxxxxxxxxxx>
Cc: Minchan Kim <minchan@xxxxxxxxxx>
Cc: Nitin Gupta <ngupta@xxxxxxxxxx>
Cc: Weijie Yang <weijie.yang@xxxxxxxxxxx>
---

Note to Seth: We talked about removing the retries parameter from
zbud_reclaim_page(), but I did not include that in this patch.
I'll send a separate patch for that.

Changes since v1 : https://lkml.org/lkml/2014/5/24/136
-Update zbud_zpool_shrink() to call zbud_reclaim_page()
in a loop until number of pages requested has been
reclaimed, or error
-Update zbud_zpool_shrink() to update passed *reclaimed
param with # pages actually reclaimed
-Update zs_pool_shrink() with new param, although function
is not implemented yet

mm/zbud.c | 92 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
mm/zsmalloc.c | 82 ++++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 174 insertions(+)

diff --git a/mm/zbud.c b/mm/zbud.c
index dd13665..645379e 100644
--- a/mm/zbud.c
+++ b/mm/zbud.c
@@ -51,6 +51,7 @@
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/zbud.h>
+#include <linux/zpool.h>

/*****************
* Structures
@@ -114,6 +115,88 @@ struct zbud_header {
};

/*****************
+ * zpool
+ ****************/
+
+#ifdef CONFIG_ZPOOL
+
+static int zbud_zpool_evict(struct zbud_pool *pool, unsigned long handle)
+{
+ return zpool_evict(pool, handle);
+}
+
+static struct zbud_ops zbud_zpool_ops = {
+ .evict = zbud_zpool_evict
+};
+
+static void *zbud_zpool_create(gfp_t gfp, struct zpool_ops *zpool_ops)
+{
+ return zbud_create_pool(gfp, &zbud_zpool_ops);
+}
+
+void zbud_zpool_destroy(void *pool)
+{
+ zbud_destroy_pool(pool);
+}
+
+int zbud_zpool_malloc(void *pool, size_t size, unsigned long *handle)
+{
+ return zbud_alloc(pool, size, handle);
+}
+void zbud_zpool_free(void *pool, unsigned long handle)
+{
+ zbud_free(pool, handle);
+}
+
+int zbud_zpool_shrink(void *pool, unsigned int pages,
+ unsigned int *reclaimed)
+{
+ unsigned int total = 0;
+ int ret = -EINVAL;
+
+ while (total < pages) {
+ ret = zbud_reclaim_page(pool, 8);
+ if (ret < 0)
+ break;
+ total++;
+ }
+
+ if (reclaimed)
+ *reclaimed = total;
+
+ return ret;
+}
+
+void *zbud_zpool_map(void *pool, unsigned long handle,
+ enum zpool_mapmode mm)
+{
+ return zbud_map(pool, handle);
+}
+void zbud_zpool_unmap(void *pool, unsigned long handle)
+{
+ zbud_unmap(pool, handle);
+}
+
+u64 zbud_zpool_total_size(void *pool)
+{
+ return zbud_get_pool_size(pool) * PAGE_SIZE;
+}
+
+static struct zpool_driver zbud_zpool_driver = {
+ .type = "zbud",
+ .create = zbud_zpool_create,
+ .destroy = zbud_zpool_destroy,
+ .malloc = zbud_zpool_malloc,
+ .free = zbud_zpool_free,
+ .shrink = zbud_zpool_shrink,
+ .map = zbud_zpool_map,
+ .unmap = zbud_zpool_unmap,
+ .total_size = zbud_zpool_total_size,
+};
+
+#endif /* CONFIG_ZPOOL */
+
+/*****************
* Helpers
*****************/
/* Just to make the code easier to read */
@@ -513,11 +596,20 @@ static int __init init_zbud(void)
/* Make sure the zbud header will fit in one chunk */
BUILD_BUG_ON(sizeof(struct zbud_header) > ZHDR_SIZE_ALIGNED);
pr_info("loaded\n");
+
+#ifdef CONFIG_ZPOOL
+ zpool_register_driver(&zbud_zpool_driver);
+#endif
+
return 0;
}

static void __exit exit_zbud(void)
{
+#ifdef CONFIG_ZPOOL
+ zpool_unregister_driver(&zbud_zpool_driver);
+#endif
+
pr_info("unloaded\n");
}

diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
index fe78189..feba644 100644
--- a/mm/zsmalloc.c
+++ b/mm/zsmalloc.c
@@ -92,6 +92,7 @@
#include <linux/spinlock.h>
#include <linux/types.h>
#include <linux/zsmalloc.h>
+#include <linux/zpool.h>

/*
* This must be power of 2 and greater than of equal to sizeof(link_free).
@@ -240,6 +241,79 @@ struct mapping_area {
enum zs_mapmode vm_mm; /* mapping mode */
};

+/* zpool driver */
+
+#ifdef CONFIG_ZPOOL
+
+static void *zs_zpool_create(gfp_t gfp, struct zpool_ops *zpool_ops)
+{
+ return zs_create_pool(gfp);
+}
+
+void zs_zpool_destroy(void *pool)
+{
+ zs_destroy_pool(pool);
+}
+
+int zs_zpool_malloc(void *pool, size_t size, unsigned long *handle)
+{
+ *handle = zs_malloc(pool, size);
+ return *handle ? 0 : -1;
+}
+void zs_zpool_free(void *pool, unsigned long handle)
+{
+ zs_free(pool, handle);
+}
+
+int zs_zpool_shrink(void *pool, unsigned int pages,
+ unsigned int *reclaimed)
+{
+ return -EINVAL;
+}
+
+void *zs_zpool_map(void *pool, unsigned long handle,
+ enum zpool_mapmode mm)
+{
+ enum zs_mapmode zs_mm;
+
+ switch (mm) {
+ case ZPOOL_MM_RO:
+ zs_mm = ZS_MM_RO;
+ break;
+ case ZPOOL_MM_WO:
+ zs_mm = ZS_MM_WO;
+ break;
+ case ZPOOL_MM_RW: /* fallthru */
+ default:
+ zs_mm = ZS_MM_RW;
+ break;
+ }
+
+ return zs_map_object(pool, handle, zs_mm);
+}
+void zs_zpool_unmap(void *pool, unsigned long handle)
+{
+ zs_unmap_object(pool, handle);
+}
+
+u64 zs_zpool_total_size(void *pool)
+{
+ return zs_get_total_size_bytes(pool);
+}
+
+static struct zpool_driver zs_zpool_driver = {
+ .type = "zsmalloc",
+ .create = zs_zpool_create,
+ .destroy = zs_zpool_destroy,
+ .malloc = zs_zpool_malloc,
+ .free = zs_zpool_free,
+ .shrink = zs_zpool_shrink,
+ .map = zs_zpool_map,
+ .unmap = zs_zpool_unmap,
+ .total_size = zs_zpool_total_size,
+};
+
+#endif /* CONFIG_ZPOOL */

/* per-cpu VM mapping areas for zspage accesses that cross page boundaries */
static DEFINE_PER_CPU(struct mapping_area, zs_map_area);
@@ -814,6 +888,10 @@ static void zs_exit(void)
{
int cpu;

+#ifdef CONFIG_ZPOOL
+ zpool_unregister_driver(&zs_zpool_driver);
+#endif
+
cpu_notifier_register_begin();

for_each_online_cpu(cpu)
@@ -840,6 +918,10 @@ static int zs_init(void)

cpu_notifier_register_done();

+#ifdef CONFIG_ZPOOL
+ zpool_register_driver(&zs_zpool_driver);
+#endif
+
return 0;
fail:
zs_exit();
--
1.8.3.1

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