Refactor existing code

This change introduces no functional changes to the memory management
interfaces.  It only restructures the existing codes by separating the
kmem, vmem, and kmem cache implementations in the separate source and
header files.

Splitting this functionality in to separate files required the addition
of spl_vmem_{init,fini}() and spl_kmem_cache_{initi,fini}() functions.

Additionally, several minor changes to the #include's were required to
accommodate the removal of extraneous header from kmem.h.

But again, while large this patch introduces no functional changes.

Signed-off-by: Brian Behlendorf <[email protected]>

1 files changed, 246 insertions, 0 deletions

diff --git a/include/sys/kmem_cache.h b/include/sys/kmem_cache.h
new file mode 100644
index 000000000..654a2ea43
--- /dev/null
+++ b/include/sys/kmem_cache.h
@@ -0,0 +1,246 @@
+/*****************************************************************************\
+ *  Copyright (C) 2007-2010 Lawrence Livermore National Security, LLC.
+ *  Copyright (C) 2007 The Regents of the University of California.
+ *  Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
+ *  Written by Brian Behlendorf <[email protected]>.
+ *  UCRL-CODE-235197
+ *
+ *  This file is part of the SPL, Solaris Porting Layer.
+ *  For details, see <http://zfsonlinux.org/>.
+ *
+ *  The SPL is free software; you can redistribute it and/or modify it
+ *  under the terms of the GNU General Public License as published by the
+ *  Free Software Foundation; either version 2 of the License, or (at your
+ *  option) any later version.
+ *
+ *  The SPL is distributed in the hope that it will be useful, but WITHOUT
+ *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ *  for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with the SPL.  If not, see <http://www.gnu.org/licenses/>.
+\*****************************************************************************/
+
+#ifndef _SPL_KMEM_CACHE_H
+#define	_SPL_KMEM_CACHE_H
+
+#include <sys/taskq.h>
+
+/*
+ * Slab allocation interfaces.  The SPL slab differs from the standard
+ * Linux SLAB or SLUB primarily in that each cache may be backed by slabs
+ * allocated from the physical or virtal memory address space.  The virtual
+ * slabs allow for good behavior when allocation large objects of identical
+ * size.  This slab implementation also supports both constructors and
+ * destructions which the Linux slab does not.
+ */
+enum {
+	KMC_BIT_NOTOUCH		= 0,	/* Don't update ages */
+	KMC_BIT_NODEBUG		= 1,	/* Default behavior */
+	KMC_BIT_NOMAGAZINE	= 2,	/* XXX: Unsupported */
+	KMC_BIT_NOHASH		= 3,	/* XXX: Unsupported */
+	KMC_BIT_QCACHE		= 4,	/* XXX: Unsupported */
+	KMC_BIT_KMEM		= 5,	/* Use kmem cache */
+	KMC_BIT_VMEM		= 6,	/* Use vmem cache */
+	KMC_BIT_SLAB		= 7,	/* Use Linux slab cache */
+	KMC_BIT_OFFSLAB		= 8,	/* Objects not on slab */
+	KMC_BIT_NOEMERGENCY	= 9,	/* Disable emergency objects */
+	KMC_BIT_DEADLOCKED      = 14,	/* Deadlock detected */
+	KMC_BIT_GROWING         = 15,   /* Growing in progress */
+	KMC_BIT_REAPING		= 16,	/* Reaping in progress */
+	KMC_BIT_DESTROY		= 17,	/* Destroy in progress */
+	KMC_BIT_TOTAL		= 18,	/* Proc handler helper bit */
+	KMC_BIT_ALLOC		= 19,	/* Proc handler helper bit */
+	KMC_BIT_MAX		= 20,	/* Proc handler helper bit */
+};
+
+/* kmem move callback return values */
+typedef enum kmem_cbrc {
+	KMEM_CBRC_YES		= 0,	/* Object moved */
+	KMEM_CBRC_NO		= 1,	/* Object not moved */
+	KMEM_CBRC_LATER		= 2,	/* Object not moved, try again later */
+	KMEM_CBRC_DONT_NEED	= 3,	/* Neither object is needed */
+	KMEM_CBRC_DONT_KNOW	= 4,	/* Object unknown */
+} kmem_cbrc_t;
+
+#define KMC_NOTOUCH		(1 << KMC_BIT_NOTOUCH)
+#define KMC_NODEBUG		(1 << KMC_BIT_NODEBUG)
+#define KMC_NOMAGAZINE		(1 << KMC_BIT_NOMAGAZINE)
+#define KMC_NOHASH		(1 << KMC_BIT_NOHASH)
+#define KMC_QCACHE		(1 << KMC_BIT_QCACHE)
+#define KMC_KMEM		(1 << KMC_BIT_KMEM)
+#define KMC_VMEM		(1 << KMC_BIT_VMEM)
+#define KMC_SLAB		(1 << KMC_BIT_SLAB)
+#define KMC_OFFSLAB		(1 << KMC_BIT_OFFSLAB)
+#define KMC_NOEMERGENCY		(1 << KMC_BIT_NOEMERGENCY)
+#define KMC_DEADLOCKED		(1 << KMC_BIT_DEADLOCKED)
+#define KMC_GROWING		(1 << KMC_BIT_GROWING)
+#define KMC_REAPING		(1 << KMC_BIT_REAPING)
+#define KMC_DESTROY		(1 << KMC_BIT_DESTROY)
+#define KMC_TOTAL		(1 << KMC_BIT_TOTAL)
+#define KMC_ALLOC		(1 << KMC_BIT_ALLOC)
+#define KMC_MAX			(1 << KMC_BIT_MAX)
+
+#define KMC_REAP_CHUNK		INT_MAX
+#define KMC_DEFAULT_SEEKS	1
+
+#define KMC_EXPIRE_AGE		0x1     /* Due to age */
+#define KMC_EXPIRE_MEM		0x2     /* Due to low memory */
+
+#define	KMC_RECLAIM_ONCE	0x1	/* Force a single shrinker pass */
+
+extern unsigned int spl_kmem_cache_expire;
+extern struct list_head spl_kmem_cache_list;
+extern struct rw_semaphore spl_kmem_cache_sem;
+
+#define SKM_MAGIC			0x2e2e2e2e
+#define SKO_MAGIC			0x20202020
+#define SKS_MAGIC			0x22222222
+#define SKC_MAGIC			0x2c2c2c2c
+
+#define SPL_KMEM_CACHE_DELAY		15	/* Minimum slab release age */
+#define SPL_KMEM_CACHE_REAP		0	/* Default reap everything */
+#define SPL_KMEM_CACHE_OBJ_PER_SLAB	16	/* Target objects per slab */
+#define SPL_KMEM_CACHE_OBJ_PER_SLAB_MIN	1	/* Minimum objects per slab */
+#define SPL_KMEM_CACHE_ALIGN		8	/* Default object alignment */
+
+#define POINTER_IS_VALID(p)		0	/* Unimplemented */
+#define POINTER_INVALIDATE(pp)			/* Unimplemented */
+
+typedef int (*spl_kmem_ctor_t)(void *, void *, int);
+typedef void (*spl_kmem_dtor_t)(void *, void *);
+typedef void (*spl_kmem_reclaim_t)(void *);
+
+typedef struct spl_kmem_magazine {
+	uint32_t		skm_magic;	/* Sanity magic */
+	uint32_t		skm_avail;	/* Available objects */
+	uint32_t		skm_size;	/* Magazine size */
+	uint32_t		skm_refill;	/* Batch refill size */
+	struct spl_kmem_cache	*skm_cache;	/* Owned by cache */
+	unsigned long		skm_age;	/* Last cache access */
+	unsigned int		skm_cpu;	/* Owned by cpu */
+	void			*skm_objs[0];	/* Object pointers */
+} spl_kmem_magazine_t;
+
+typedef struct spl_kmem_obj {
+        uint32_t		sko_magic;	/* Sanity magic */
+	void			*sko_addr;	/* Buffer address */
+	struct spl_kmem_slab	*sko_slab;	/* Owned by slab */
+	struct list_head	sko_list;	/* Free object list linkage */
+} spl_kmem_obj_t;
+
+typedef struct spl_kmem_slab {
+        uint32_t		sks_magic;	/* Sanity magic */
+	uint32_t		sks_objs;	/* Objects per slab */
+	struct spl_kmem_cache	*sks_cache;	/* Owned by cache */
+	struct list_head	sks_list;	/* Slab list linkage */
+	struct list_head	sks_free_list;	/* Free object list */
+	unsigned long		sks_age;	/* Last modify jiffie */
+	uint32_t		sks_ref;	/* Ref count used objects */
+} spl_kmem_slab_t;
+
+typedef struct spl_kmem_alloc {
+	struct spl_kmem_cache	*ska_cache;	/* Owned by cache */
+	int			ska_flags;	/* Allocation flags */
+	taskq_ent_t		ska_tqe;	/* Task queue entry */
+} spl_kmem_alloc_t;
+
+typedef struct spl_kmem_emergency {
+	struct rb_node		ske_node;	/* Emergency tree linkage */
+	void			*ske_obj;	/* Buffer address */
+} spl_kmem_emergency_t;
+
+typedef struct spl_kmem_cache {
+	uint32_t		skc_magic;	/* Sanity magic */
+	uint32_t		skc_name_size;	/* Name length */
+	char			*skc_name;	/* Name string */
+	spl_kmem_magazine_t	*skc_mag[NR_CPUS]; /* Per-CPU warm cache */
+	uint32_t		skc_mag_size;	/* Magazine size */
+	uint32_t		skc_mag_refill;	/* Magazine refill count */
+	spl_kmem_ctor_t		skc_ctor;	/* Constructor */
+	spl_kmem_dtor_t		skc_dtor;	/* Destructor */
+	spl_kmem_reclaim_t	skc_reclaim;	/* Reclaimator */
+	void			*skc_private;	/* Private data */
+	void			*skc_vmp;	/* Unused */
+	struct kmem_cache	*skc_linux_cache; /* Linux slab cache if used */
+	unsigned long		skc_flags;	/* Flags */
+	uint32_t		skc_obj_size;	/* Object size */
+	uint32_t		skc_obj_align;	/* Object alignment */
+	uint32_t		skc_slab_objs;	/* Objects per slab */
+	uint32_t		skc_slab_size;	/* Slab size */
+	uint32_t		skc_delay;	/* Slab reclaim interval */
+	uint32_t		skc_reap;	/* Slab reclaim count */
+	atomic_t		skc_ref;	/* Ref count callers */
+	taskqid_t		skc_taskqid;	/* Slab reclaim task */
+	struct list_head	skc_list;	/* List of caches linkage */
+	struct list_head	skc_complete_list;/* Completely alloc'ed */
+	struct list_head	skc_partial_list; /* Partially alloc'ed */
+	struct rb_root		skc_emergency_tree; /* Min sized objects */
+	spinlock_t		skc_lock;	/* Cache lock */
+	wait_queue_head_t	skc_waitq;	/* Allocation waiters */
+	uint64_t		skc_slab_fail;	/* Slab alloc failures */
+	uint64_t		skc_slab_create;/* Slab creates */
+	uint64_t		skc_slab_destroy;/* Slab destroys */
+	uint64_t		skc_slab_total;	/* Slab total current */
+	uint64_t		skc_slab_alloc;	/* Slab alloc current */
+	uint64_t		skc_slab_max;	/* Slab max historic  */
+	uint64_t		skc_obj_total;	/* Obj total current */
+	uint64_t		skc_obj_alloc;	/* Obj alloc current */
+	uint64_t		skc_obj_max;	/* Obj max historic */
+	uint64_t		skc_obj_deadlock;  /* Obj emergency deadlocks */
+	uint64_t		skc_obj_emergency; /* Obj emergency current */
+	uint64_t		skc_obj_emergency_max; /* Obj emergency max */
+} spl_kmem_cache_t;
+#define kmem_cache_t		spl_kmem_cache_t
+
+extern spl_kmem_cache_t *spl_kmem_cache_create(char *name, size_t size,
+	size_t align, spl_kmem_ctor_t ctor, spl_kmem_dtor_t dtor,
+	spl_kmem_reclaim_t reclaim, void *priv, void *vmp, int flags);
+extern void spl_kmem_cache_set_move(spl_kmem_cache_t *,
+	kmem_cbrc_t (*)(void *, void *, size_t, void *));
+extern void spl_kmem_cache_destroy(spl_kmem_cache_t *skc);
+extern void *spl_kmem_cache_alloc(spl_kmem_cache_t *skc, int flags);
+extern void spl_kmem_cache_free(spl_kmem_cache_t *skc, void *obj);
+extern void spl_kmem_cache_reap_now(spl_kmem_cache_t *skc, int count);
+extern void spl_kmem_reap(void);
+
+#define kmem_cache_create(name,size,align,ctor,dtor,rclm,priv,vmp,flags) \
+        spl_kmem_cache_create(name,size,align,ctor,dtor,rclm,priv,vmp,flags)
+#define kmem_cache_set_move(skc, move)	spl_kmem_cache_set_move(skc, move)
+#define kmem_cache_destroy(skc)		spl_kmem_cache_destroy(skc)
+#define kmem_cache_alloc(skc, flags)	spl_kmem_cache_alloc(skc, flags)
+#define kmem_cache_free(skc, obj)	spl_kmem_cache_free(skc, obj)
+#define kmem_cache_reap_now(skc)	\
+        spl_kmem_cache_reap_now(skc, skc->skc_reap)
+#define kmem_reap()			spl_kmem_reap()
+#define kmem_virt(ptr)			(((ptr) >= (void *)VMALLOC_START) && \
+					 ((ptr) <  (void *)VMALLOC_END))
+
+/*
+ * Allow custom slab allocation flags to be set for KMC_SLAB based caches.
+ * One use for this function is to ensure the __GFP_COMP flag is part of
+ * the default allocation mask which ensures higher order allocations are
+ * properly refcounted.  This flag was added to the default ->allocflags
+ * as of Linux 3.11.
+ */
+static inline void
+kmem_cache_set_allocflags(spl_kmem_cache_t *skc, gfp_t flags)
+{
+	if (skc->skc_linux_cache == NULL)
+		return;
+
+#if defined(HAVE_KMEM_CACHE_ALLOCFLAGS)
+	skc->skc_linux_cache->allocflags |= flags;
+#elif defined(HAVE_KMEM_CACHE_GFPFLAGS)
+	skc->skc_linux_cache->gfpflags |= flags;
+#endif
+}
+
+/*
+ * The following functions are only available for internal use.
+ */
+extern int spl_kmem_cache_init(void);
+extern void spl_kmem_cache_fini(void);
+
+#endif	/* _SPL_KMEM_CACHE_H */