diff options
Diffstat (limited to 'lib/slab.c')
-rw-r--r-- | lib/slab.c | 138 |
1 files changed, 81 insertions, 57 deletions
@@ -32,6 +32,7 @@ #include "nest/bird.h" #include "lib/resource.h" #include "lib/string.h" +#include "lib/tlists.h" #undef FAKE_SLAB /* Turn on if you want to debug memory allocations */ @@ -40,7 +41,7 @@ #endif static void slab_free(resource *r); -static void slab_dump(resource *r); +static void slab_dump(resource *r, unsigned indent); static resource *slab_lookup(resource *r, unsigned long addr); static struct resmem slab_memsize(resource *r); @@ -98,7 +99,7 @@ sl_allocz(slab *s) } void -sl_free(slab *s, void *oo) +sl_free(void *oo) { struct sl_obj *o = SKIP_BACK(struct sl_obj, data, oo); @@ -117,7 +118,7 @@ slab_free(resource *r) } static void -slab_dump(resource *r) +slab_dump(resource *r, unsigned indent UNUSED) { slab *s = (slab *) r; int cnt = 0; @@ -153,12 +154,38 @@ slab_memsize(resource *r) #define MAX_EMPTY_HEADS 1 +enum sl_head_state { + slh_empty = 2, + slh_partial = 0, + slh_full = 1, +} PACKED; + +struct sl_head { + struct slab *slab; + TLIST_NODE(sl_head, struct sl_head) n; + u16 num_full; + enum sl_head_state state; + u32 used_bits[0]; +}; + +struct sl_alignment { /* Magic structure for testing of alignment */ + byte data; + int x[0]; +}; + +#define TLIST_PREFIX sl_head +#define TLIST_TYPE struct sl_head +#define TLIST_ITEM n +#define TLIST_WANT_WALK +#define TLIST_WANT_ADD_HEAD + +#include "lib/tlists.h" + struct slab { resource r; - pool *p; uint obj_size, head_size, head_bitfield_len; uint objs_per_slab, num_empty_heads, data_size; - list empty_heads, partial_heads, full_heads; + struct sl_head_list empty_heads, partial_heads, full_heads; }; static struct resclass sl_class = { @@ -170,18 +197,15 @@ static struct resclass sl_class = { slab_memsize }; -struct sl_head { - node n; - u32 num_full; - u32 used_bits[0]; -}; +#define SL_GET_HEAD(x) PAGE_HEAD(x) -struct sl_alignment { /* Magic structure for testing of alignment */ - byte data; - int x[0]; -}; +#define SL_HEAD_CHANGE_STATE(_s, _h, _from, _to) ({ \ + ASSERT_DIE(_h->state == slh_##_from); \ + sl_head_rem_node(&_s->_from##_heads, _h); \ + sl_head_add_head(&_s->_to##_heads, _h); \ + _h->state = slh_##_to; \ + }) -#define SL_GET_HEAD(x) ((struct sl_head *) PAGE_HEAD(x)) /** * sl_new - create a new Slab @@ -195,10 +219,9 @@ slab * sl_new(pool *p, uint size) { slab *s = ralloc(p, &sl_class); - s->p = p; uint align = sizeof(struct sl_alignment); - if (align < sizeof(int)) - align = sizeof(int); + if (align < sizeof(void *)) + align = sizeof(void *); s->data_size = size; size = (size + align - 1) / align * align; s->obj_size = size; @@ -213,15 +236,12 @@ sl_new(pool *p, uint size) + sizeof(u32) * s->head_bitfield_len + align - 1) / align * align; - } while (s->objs_per_slab * size + s->head_size > (uint) page_size); + } while (s->objs_per_slab * size + s->head_size > (size_t) page_size); if (!s->objs_per_slab) bug("Slab: object too large"); s->num_empty_heads = 0; - init_list(&s->empty_heads); - init_list(&s->partial_heads); - init_list(&s->full_heads); return s; } @@ -238,8 +258,7 @@ sl_alloc(slab *s) struct sl_head *h; redo: - h = HEAD(s->partial_heads); - if (!h->n.next) + if (!(h = s->partial_heads.first)) goto no_partial; okay: for (uint i=0; i<s->head_bitfield_len; i++) @@ -259,26 +278,27 @@ okay: return out; } - rem_node(&h->n); - add_tail(&s->full_heads, &h->n); + SL_HEAD_CHANGE_STATE(s, h, partial, full); goto redo; no_partial: - h = HEAD(s->empty_heads); - if (h->n.next) + if (h = s->empty_heads.first) { - rem_node(&h->n); - add_head(&s->partial_heads, &h->n); + SL_HEAD_CHANGE_STATE(s, h, empty, partial); s->num_empty_heads--; goto okay; } + h = alloc_page(); + ASSERT_DIE(SL_GET_HEAD(h) == h); + #ifdef POISON memset(h, 0xba, page_size); #endif - ASSERT_DIE(SL_GET_HEAD(h) == h); + memset(h, 0, s->head_size); - add_head(&s->partial_heads, &h->n); + h->slab = s; + sl_head_add_head(&s->partial_heads, h); goto okay; } @@ -307,9 +327,10 @@ sl_allocz(slab *s) * and returns it back to the Slab @s. */ void -sl_free(slab *s, void *oo) +sl_free(void *oo) { struct sl_head *h = SL_GET_HEAD(oo); + struct slab *s = h->slab; #ifdef POISON memset(oo, 0xdb, s->data_size); @@ -322,14 +343,11 @@ sl_free(slab *s, void *oo) h->used_bits[pos / 32] &= ~(1 << (pos % 32)); - if (h->num_full-- == s->objs_per_slab) - { - rem_node(&h->n); - add_head(&s->partial_heads, &h->n); - } + if ((h->num_full-- == s->objs_per_slab) && (h->state == slh_full)) + SL_HEAD_CHANGE_STATE(s, h, full, partial); else if (!h->num_full) { - rem_node(&h->n); + sl_head_rem_node(&s->partial_heads, h); if (s->num_empty_heads >= MAX_EMPTY_HEADS) { #ifdef POISON @@ -339,7 +357,8 @@ sl_free(slab *s, void *oo) } else { - add_head(&s->empty_heads, &h->n); + sl_head_add_head(&s->empty_heads, h); + h->state = slh_empty; s->num_empty_heads++; } } @@ -349,30 +368,37 @@ static void slab_free(resource *r) { slab *s = (slab *) r; - struct sl_head *h, *g; - WALK_LIST_DELSAFE(h, g, s->empty_heads) + WALK_TLIST_DELSAFE(sl_head, h, &s->empty_heads) free_page(h); - WALK_LIST_DELSAFE(h, g, s->partial_heads) + WALK_TLIST_DELSAFE(sl_head, h, &s->partial_heads) free_page(h); - WALK_LIST_DELSAFE(h, g, s->full_heads) + WALK_TLIST_DELSAFE(sl_head, h, &s->full_heads) free_page(h); } static void -slab_dump(resource *r) +slab_dump(resource *r, unsigned indent UNUSED) { slab *s = (slab *) r; int ec=0, pc=0, fc=0; - struct sl_head *h; - WALK_LIST(h, s->empty_heads) + WALK_TLIST(sl_head, h, &s->empty_heads) ec++; - WALK_LIST(h, s->partial_heads) + WALK_TLIST(sl_head, h, &s->partial_heads) pc++; - WALK_LIST(h, s->full_heads) + WALK_TLIST(sl_head, h, &s->full_heads) fc++; debug("(%de+%dp+%df blocks per %d objs per %d bytes)\n", ec, pc, fc, s->objs_per_slab, s->obj_size); + + char x[16]; + bsprintf(x, "%%%ds%%s %%p\n", indent + 2); + WALK_TLIST(sl_head, h, &s->full_heads) + debug(x, "", "full", h); + WALK_TLIST(sl_head, h, &s->partial_heads) + debug(x, "", "partial", h); + WALK_TLIST(sl_head, h, &s->empty_heads) + debug(x, "", "empty", h); } static struct resmem @@ -380,23 +406,22 @@ slab_memsize(resource *r) { slab *s = (slab *) r; size_t heads = 0; - struct sl_head *h; - WALK_LIST(h, s->full_heads) + WALK_TLIST(sl_head, h, &s->full_heads) heads++; size_t items = heads * s->objs_per_slab; - WALK_LIST(h, s->partial_heads) + WALK_TLIST(sl_head, h, &s->partial_heads) { heads++; items += h->num_full; } - WALK_LIST(h, s->empty_heads) + WALK_TLIST(sl_head, h, &s->empty_heads) heads++; - size_t eff = items * s->obj_size; + size_t eff = items * s->data_size; return (struct resmem) { .effective = eff, @@ -408,12 +433,11 @@ static resource * slab_lookup(resource *r, unsigned long a) { slab *s = (slab *) r; - struct sl_head *h; - WALK_LIST(h, s->partial_heads) + WALK_TLIST(sl_head, h, &s->partial_heads) if ((unsigned long) h < a && (unsigned long) h + page_size < a) return r; - WALK_LIST(h, s->full_heads) + WALK_TLIST(sl_head, h, &s->full_heads) if ((unsigned long) h < a && (unsigned long) h + page_size < a) return r; return NULL; |