diff options
| -rw-r--r-- | ChangeLog | 4 | ||||
| -rw-r--r-- | lib/fuse.c | 189 |
2 files changed, 184 insertions, 9 deletions
@@ -2,6 +2,10 @@ * Highlevel lib: allow hash tables to shrink + * Highlevel lib: add slab allocation for node cache. This will + allow the memory used by the filesystem to grow and shrink + depending on how many inodes are currently cached. + 2010-12-13 Miklos Szeredi <miklos@szeredi.hu> * Highlevel lib: use dynamically resized hash table for looking up @@ -33,6 +33,13 @@ #include <sys/param.h> #include <sys/uio.h> #include <sys/time.h> +#include <sys/mman.h> + +#define FUSE_NODE_SLAB 1 + +#ifndef MAP_ANONYMOUS +#undef FUSE_NODE_SLAB +#endif #define FUSE_DEFAULT_INTR_SIGNAL SIGUSR1 @@ -93,6 +100,17 @@ struct node_table { size_t split; }; +struct list_head { + struct list_head *next; + struct list_head *prev; +}; + +struct node_slab { + struct list_head list; /* must be the first member */ + struct list_head freelist; + int used; +}; + struct fuse { struct fuse_session *se; struct node_table name_table; @@ -107,6 +125,9 @@ struct fuse { int nullpath_ok; int curr_ticket; struct lock_queue_element *lockq; + int pagesize; + struct list_head partial_slabs; + struct list_head full_slabs; }; struct lock { @@ -267,6 +288,149 @@ static void fuse_put_module(struct fuse_module *m) pthread_mutex_unlock(&fuse_context_lock); } +static void init_list_head(struct list_head *list) +{ + list->next = list; + list->prev = list; +} + +static int list_empty(const struct list_head *head) +{ + return head->next == head; +} + +#ifdef FUSE_NODE_SLAB +static void list_add(struct list_head *new, struct list_head *prev, + struct list_head *next) +{ + next->prev = new; + new->next = next; + new->prev = prev; + prev->next = new; +} + +static void list_add_head(struct list_head *new, struct list_head *head) +{ + list_add(new, head, head->next); +} + +static void list_add_tail(struct list_head *new, struct list_head *head) +{ + list_add(new, head->prev, head); +} + +static inline void list_del(struct list_head *entry) +{ + struct list_head *prev = entry->prev; + struct list_head *next = entry->next; + + next->prev = prev; + prev->next = next; +} + +static struct node_slab *list_to_slab(struct list_head *head) +{ + return (struct node_slab *) head; +} + +static struct node_slab *node_to_slab(struct fuse *f, struct node *node) +{ + return (struct node_slab *) (((uintptr_t) node) & ~((uintptr_t) f->pagesize - 1)); +} + +static int alloc_slab(struct fuse *f) +{ + void *mem; + struct node_slab *slab; + char *start; + size_t num; + size_t i; + + mem = mmap(NULL, f->pagesize, PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); + + if (mem == MAP_FAILED) + return -1; + + slab = mem; + init_list_head(&slab->freelist); + slab->used = 0; + num = (f->pagesize - sizeof(struct node_slab)) / sizeof(struct node); + + start = (char *) mem + f->pagesize - num * sizeof(struct node); + for (i = 0; i < num; i++) { + struct list_head *n; + + n = (struct list_head *) (start + i * sizeof(struct node)); + list_add_tail(n, &slab->freelist); + } + list_add_tail(&slab->list, &f->partial_slabs); + + return 0; +} + +static struct node *alloc_node(struct fuse *f) +{ + struct node_slab *slab; + struct list_head *node; + + if (list_empty(&f->partial_slabs)) { + int res = alloc_slab(f); + if (res != 0) + return NULL; + } + slab = list_to_slab(f->partial_slabs.next); + slab->used++; + node = slab->freelist.next; + list_del(node); + if (list_empty(&slab->freelist)) { + list_del(&slab->list); + list_add_tail(&slab->list, &f->full_slabs); + } + + return (struct node *) node; +} + +static void free_slab(struct fuse *f, struct node_slab *slab) +{ + int res; + + list_del(&slab->list); + res = munmap(slab, f->pagesize); + if (res == -1) + fprintf(stderr, "fuse warning: munmap(%p) failed\n", slab); +} + +static void free_node_mem(struct fuse *f, struct node *node) +{ + struct node_slab *slab = node_to_slab(f, node); + struct list_head *n = (struct list_head *) node; + + slab->used--; + if (slab->used) { + if (list_empty(&slab->freelist)) { + list_del(&slab->list); + list_add_tail(&slab->list, &f->partial_slabs); + } + list_add_head(n, &slab->freelist); + } else { + free_slab(f, slab); + } +} +#else +static struct node *alloc_node(struct fuse *f) +{ + (void) f; + return (struct node *) calloc(1, sizeof(struct node)); +} + +static void free_node_mem(struct fuse *f, struct node *node) +{ + (void) f; + free(node); +} +#endif + static size_t id_hash(struct fuse *f, fuse_ino_t ino) { uint64_t hash = ((uint32_t) ino * 2654435761) % f->id_table.size; @@ -301,11 +465,11 @@ static struct node *get_node(struct fuse *f, fuse_ino_t nodeid) return node; } -static void free_node(struct node *node) +static void free_node(struct fuse *f, struct node *node) { if (node->name != node->inline_name) free(node->name); - free(node); + free_node_mem(f, node); } static void node_table_reduce(struct node_table *t) @@ -332,7 +496,7 @@ static void remerge_id(struct fuse *f) if (t->split == 0) node_table_reduce(t); - for (iter = 4; t->split > 0 && iter; iter--) { + for (iter = 8; t->split > 0 && iter; iter--) { struct node **upper; t->split--; @@ -449,7 +613,7 @@ static void remerge_name(struct fuse *f) if (t->split == 0) node_table_reduce(t); - for (iter = 4; t->split > 0 && iter; iter--) { + for (iter = 8; t->split > 0 && iter; iter--) { struct node **upper; t->split--; @@ -559,7 +723,7 @@ static void delete_node(struct fuse *f, struct node *node) assert(node->treelock == 0); assert(!node->name); unhash_id(f, node); - free_node(node); + free_node(f, node); } static void unref_node(struct fuse *f, struct node *node) @@ -606,7 +770,7 @@ static struct node *find_node(struct fuse *f, fuse_ino_t parent, else node = lookup_node(f, parent, name); if (node == NULL) { - node = (struct node *) calloc(1, sizeof(struct node)); + node = alloc_node(f); if (node == NULL) goto out_err; @@ -620,7 +784,7 @@ static struct node *find_node(struct fuse *f, fuse_ino_t parent, node->treelock = 0; node->ticket = 0; if (hash_name(f, node, parent, name) == -1) { - free(node); + free_node(f, node); node = NULL; goto out_err; } @@ -4044,6 +4208,10 @@ struct fuse *fuse_new_common(struct fuse_chan *ch, struct fuse_args *args, f->conf.negative_timeout = 0.0; f->conf.intr_signal = FUSE_DEFAULT_INTR_SIGNAL; + f->pagesize = getpagesize(); + init_list_head(&f->partial_slabs); + init_list_head(&f->full_slabs); + if (fuse_opt_parse(args, &f->conf, fuse_lib_opts, fuse_lib_opt_proc) == -1) goto out_free_fs; @@ -4105,7 +4273,7 @@ struct fuse *fuse_new_common(struct fuse_chan *ch, struct fuse_args *args, fuse_mutex_init(&f->lock); - root = (struct node *) calloc(1, sizeof(struct node)); + root = alloc_node(f); if (root == NULL) { fprintf(stderr, "fuse: memory allocation failed\n"); goto out_free_id_table; @@ -4191,9 +4359,12 @@ void fuse_destroy(struct fuse *f) for (node = f->id_table.array[i]; node != NULL; node = next) { next = node->id_next; - free_node(node); + free_node(f, node); + f->id_table.use--; } } + assert(list_empty(&f->partial_slabs)); + assert(list_empty(&f->full_slabs)); free(f->id_table.array); free(f->name_table.array); |