staging: zcache: enable zcache to be built/loaded as a module
Allow zcache to be built/loaded as a module. Note runtime dependency
disallows loading if cleancache/frontswap lazy initialization patches
are not present. Zsmalloc support has not yet been merged into zcache
but, once merged, could now easily be selected via a module_param.
If built-in (not built as a module), the original mechanism of enabling
via a kernel boot parameter is retained, but this should be considered
deprecated.
Note that module unload is explicitly not yet supported.
Signed-off-by: Dan Magenheimer <dan.magenheimer@oracle.com>
[v1: Rebased with different order of patches]
[v2: Removed [CLEANCACHE|FRONTSWAP]_HAS_LAZY_INIT ifdef]
[v3: Rebased on top of ramster->zcache move]
[v4: Redid the Makefile]
[v5: s/ZCACHE2/ZCACHE/]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Bob Liu <lliubbo@gmail.com>
Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Cc: Andor Daam <andor.daam@googlemail.com>
Cc: Florian Schmaus <fschmaus@gmail.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Stefan Hengelein <ilendir@googlemail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/staging/zcache/Kconfig b/drivers/staging/zcache/Kconfig
index 05e87a1..2d7b2da 100644
--- a/drivers/staging/zcache/Kconfig
+++ b/drivers/staging/zcache/Kconfig
@@ -1,5 +1,5 @@
config ZCACHE
- bool "Dynamic compression of swap pages and clean pagecache pages"
+ tristate "Dynamic compression of swap pages and clean pagecache pages"
depends on CRYPTO=y && SWAP=y && CLEANCACHE && FRONTSWAP
select CRYPTO_LZO
default n
@@ -19,8 +19,8 @@
how zcache is doing. You probably want to set this to 'N'.
config RAMSTER
- bool "Cross-machine RAM capacity sharing, aka peer-to-peer tmem"
- depends on CONFIGFS_FS=y && SYSFS=y && !HIGHMEM && ZCACHE=y
+ tristate "Cross-machine RAM capacity sharing, aka peer-to-peer tmem"
+ depends on CONFIGFS_FS=y && SYSFS=y && !HIGHMEM && ZCACHE
depends on NET
# must ensure struct page is 8-byte aligned
select HAVE_ALIGNED_STRUCT_PAGE if !64BIT
diff --git a/drivers/staging/zcache/tmem.c b/drivers/staging/zcache/tmem.c
index a2b7e03..d7e51e4 100644
--- a/drivers/staging/zcache/tmem.c
+++ b/drivers/staging/zcache/tmem.c
@@ -35,7 +35,8 @@
#include <linux/list.h>
#include <linux/spinlock.h>
#include <linux/atomic.h>
-#ifdef CONFIG_RAMSTER
+#include <linux/export.h>
+#if defined(CONFIG_RAMSTER) || defined(CONFIG_RAMSTER_MODULE)
#include <linux/delay.h>
#endif
@@ -641,6 +642,7 @@
/* note, hashbucket remains locked */
return pampd;
}
+EXPORT_SYMBOL_GPL(tmem_localify_get_pampd);
void tmem_localify_finish(struct tmem_obj *obj, uint32_t index,
void *pampd, void *saved_hb, bool delete)
@@ -658,6 +660,7 @@
}
spin_unlock(&hb->lock);
}
+EXPORT_SYMBOL_GPL(tmem_localify_finish);
/*
* For ramster only. Helper function to support asynchronous tmem_get.
@@ -719,6 +722,7 @@
spin_unlock(&hb->lock);
return ret;
}
+EXPORT_SYMBOL_GPL(tmem_replace);
#endif
/*
diff --git a/drivers/staging/zcache/tmem.h b/drivers/staging/zcache/tmem.h
index adbe5a8..d128ce2 100644
--- a/drivers/staging/zcache/tmem.h
+++ b/drivers/staging/zcache/tmem.h
@@ -126,7 +126,7 @@
TMEM_HASH_BUCKET_BITS);
}
-#ifdef CONFIG_RAMSTER
+#if defined(CONFIG_RAMSTER) || defined(CONFIG_RAMSTER_MODULE)
struct tmem_xhandle {
uint8_t client_id;
uint8_t xh_data_cksum;
@@ -171,7 +171,7 @@
unsigned int objnode_tree_height;
unsigned long objnode_count;
long pampd_count;
-#ifdef CONFIG_RAMSTER
+#if defined(CONFIG_RAMSTER) || defined(CONFIG_RAMSTER_MODULE)
/*
* for current design of ramster, all pages belonging to
* an object reside on the same remotenode and extra is
@@ -215,7 +215,7 @@
uint32_t);
void (*free)(void *, struct tmem_pool *,
struct tmem_oid *, uint32_t, bool);
-#ifdef CONFIG_RAMSTER
+#if defined(CONFIG_RAMSTER) || defined(CONFIG_RAMSTER_MODULE)
void (*new_obj)(struct tmem_obj *);
void (*free_obj)(struct tmem_pool *, struct tmem_obj *, bool);
void *(*repatriate_preload)(void *, struct tmem_pool *,
@@ -247,7 +247,7 @@
extern int tmem_flush_object(struct tmem_pool *, struct tmem_oid *);
extern int tmem_destroy_pool(struct tmem_pool *);
extern void tmem_new_pool(struct tmem_pool *, uint32_t);
-#ifdef CONFIG_RAMSTER
+#if defined(CONFIG_RAMSTER) || defined(CONFIG_RAMSTER_MODULE)
extern int tmem_replace(struct tmem_pool *, struct tmem_oid *, uint32_t index,
void *);
extern void *tmem_localify_get_pampd(struct tmem_pool *, struct tmem_oid *,
diff --git a/drivers/staging/zcache/zcache-main.c b/drivers/staging/zcache/zcache-main.c
index 326c2ea..522cb8e 100644
--- a/drivers/staging/zcache/zcache-main.c
+++ b/drivers/staging/zcache/zcache-main.c
@@ -37,8 +37,10 @@
#include "debug.h"
#ifdef CONFIG_RAMSTER
static bool ramster_enabled __read_mostly;
+static int disable_frontswap_selfshrink;
#else
#define ramster_enabled false
+#define disable_frontswap_selfshrink 0
#endif
#ifndef __PG_WAS_ACTIVE
@@ -81,8 +83,12 @@
(__GFP_FS | __GFP_NORETRY | __GFP_NOWARN | __GFP_NOMEMALLOC)
/* crypto API for zcache */
+#ifdef CONFIG_ZCACHE_MODULE
+static char *zcache_comp_name = "lzo";
+#else
#define ZCACHE_COMP_NAME_SZ CRYPTO_MAX_ALG_NAME
static char zcache_comp_name[ZCACHE_COMP_NAME_SZ] __read_mostly;
+#endif
static struct crypto_comp * __percpu *zcache_comp_pcpu_tfms __read_mostly;
enum comp_op {
@@ -1721,6 +1727,7 @@
* OR NOTHING HAPPENS!
*/
+#ifndef CONFIG_ZCACHE_MODULE
static int __init enable_zcache(char *s)
{
zcache_enabled = true;
@@ -1787,18 +1794,27 @@
return 1;
}
__setup("zcache=", enable_zcache_compressor);
+#endif
-static int __init zcache_comp_init(void)
+static int zcache_comp_init(void)
{
int ret = 0;
/* check crypto algorithm */
+#ifdef CONFIG_ZCACHE_MODULE
+ ret = crypto_has_comp(zcache_comp_name, 0, 0);
+ if (!ret) {
+ ret = -1;
+ goto out;
+ }
+#else
if (*zcache_comp_name != '\0') {
ret = crypto_has_comp(zcache_comp_name, 0, 0);
if (!ret)
pr_info("zcache: %s not supported\n",
zcache_comp_name);
+ goto out;
}
if (!ret)
strcpy(zcache_comp_name, "lzo");
@@ -1807,6 +1823,7 @@
ret = 1;
goto out;
}
+#endif
pr_info("zcache: using %s compressor\n", zcache_comp_name);
/* alloc percpu transforms */
@@ -1818,10 +1835,13 @@
return ret;
}
-static int __init zcache_init(void)
+static int zcache_init(void)
{
int ret = 0;
+#ifdef CONFIG_ZCACHE_MODULE
+ zcache_enabled = 1;
+#endif
if (ramster_enabled) {
namestr = "ramster";
ramster_register_pamops(&zcache_pamops);
@@ -1894,9 +1914,28 @@
}
if (ramster_enabled)
ramster_init(!disable_cleancache, !disable_frontswap,
- frontswap_has_exclusive_gets, false);
+ frontswap_has_exclusive_gets,
+ !disable_frontswap_selfshrink);
out:
return ret;
}
+#ifdef CONFIG_ZCACHE_MODULE
+#ifdef CONFIG_RAMSTER
+module_param(ramster_enabled, int, S_IRUGO);
+module_param(disable_frontswap_selfshrink, int, S_IRUGO);
+#endif
+module_param(disable_cleancache, int, S_IRUGO);
+module_param(disable_frontswap, int, S_IRUGO);
+#ifdef FRONTSWAP_HAS_EXCLUSIVE_GETS
+module_param(frontswap_has_exclusive_gets, bool, S_IRUGO);
+#endif
+module_param(disable_frontswap_ignore_nonactive, int, S_IRUGO);
+module_param(zcache_comp_name, charp, S_IRUGO);
+module_init(zcache_init);
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Dan Magenheimer <dan.magenheimer@oracle.com>");
+MODULE_DESCRIPTION("In-kernel compression of cleancache/frontswap pages");
+#else
late_initcall(zcache_init);
+#endif
diff --git a/drivers/staging/zcache/zcache.h b/drivers/staging/zcache/zcache.h
index 81722b3..8491200 100644
--- a/drivers/staging/zcache/zcache.h
+++ b/drivers/staging/zcache/zcache.h
@@ -39,7 +39,7 @@
extern int zcache_flush_object(int, int, struct tmem_oid *);
extern void zcache_decompress_to_page(char *, unsigned int, struct page *);
-#ifdef CONFIG_RAMSTER
+#if defined(CONFIG_RAMSTER) || defined(CONFIG_RAMSTER_MODULE)
extern void *zcache_pampd_create(char *, unsigned int, bool, int,
struct tmem_handle *);
int zcache_autocreate_pool(unsigned int cli_id, unsigned int pool_id, bool eph);