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author | Alex Auvolat <alex.auvolat@ens.fr> | 2014-12-06 18:39:12 +0100 |
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committer | Alex Auvolat <alex.auvolat@ens.fr> | 2014-12-06 18:39:12 +0100 |
commit | ff27e3d5ca61fb6234b0876dc3368d0e5dfc5a95 (patch) | |
tree | e7945b5cae3925ae50082da7b80e9b3caf914fa4 /kernel/lib | |
parent | 274765f7daa3cc1094f9f26196fcf2b9a5289ee2 (diff) | |
download | macroscope-ff27e3d5ca61fb6234b0876dc3368d0e5dfc5a95.tar.gz macroscope-ff27e3d5ca61fb6234b0876dc3368d0e5dfc5a95.zip |
Trying to track an annoying bug.
Diffstat (limited to 'kernel/lib')
-rw-r--r-- | kernel/lib/slab_alloc.c | 62 |
1 files changed, 47 insertions, 15 deletions
diff --git a/kernel/lib/slab_alloc.c b/kernel/lib/slab_alloc.c index 9ec39b0..d9efc4f 100644 --- a/kernel/lib/slab_alloc.c +++ b/kernel/lib/slab_alloc.c @@ -32,7 +32,7 @@ struct mem_allocator { const slab_type_t *types; slab_t *slabs; cache_t *first_free_region_descriptor; - cache_t *all_regions; + cache_t *all_caches, *all_other_regions;; page_alloc_fun_t alloc_fun; page_free_fun_t free_fun; @@ -49,8 +49,13 @@ void add_free_region_descriptor(mem_allocator_t *a, cache_t *c) { cache_t *take_region_descriptor(mem_allocator_t *a) { if (a->first_free_region_descriptor == 0) { - // TODO : allocate more descriptors (not complicated) - return 0; + void* p = a->alloc_fun(PAGE_SIZE); + if (p == 0) return 0; + + void* end = p + PAGE_SIZE; + for (cache_t *i = (cache_t*)p; i + 1 <= (cache_t*)end; i++) { + add_free_region_descriptor(a, i); + } } cache_t *x = a->first_free_region_descriptor; a->first_free_region_descriptor = x->next_region; @@ -76,7 +81,7 @@ mem_allocator_t* create_slab_allocator(const slab_type_t *types, page_alloc_fun_ mem_allocator_t *a = ptr.a; ptr.a++; - a->all_regions = 0; + a->all_caches = a->all_other_regions = 0; a->alloc_fun = af; a->free_fun = ff; @@ -99,11 +104,13 @@ mem_allocator_t* create_slab_allocator(const slab_type_t *types, page_alloc_fun_ static void stack_and_destroy_regions(page_free_fun_t ff, cache_t *r) { if (r == 0) return; void* addr = r->region_addr; + ASSERT(r != r->next_region); stack_and_destroy_regions(ff, r->next_region); ff(addr); } void destroy_slab_allocator(mem_allocator_t *a) { - stack_and_destroy_regions(a->free_fun, a->all_regions); + stack_and_destroy_regions(a->free_fun, a->all_caches); + stack_and_destroy_regions(a->free_fun, a->all_other_regions); a->free_fun(a); } @@ -140,8 +147,8 @@ void* slab_alloc(mem_allocator_t* a, size_t sz) { } ASSERT(fc->n_free_objs == cache_size / obj_size); - fc->next_region = a->all_regions; - a->all_regions = fc; + fc->next_region = a->all_caches; + a->all_caches = fc; fc->c.next_cache = a->slabs[i].first_cache; a->slabs[i].first_cache = fc; } @@ -167,8 +174,8 @@ void* slab_alloc(mem_allocator_t* a, size_t sz) { r->is_a_cache = 0; r->sr.region_size = sz; - r->next_region = a->all_regions; - a->all_regions = r; + r->next_region = a->all_other_regions; + a->all_other_regions = r; return (void*)r->region_addr; } @@ -186,7 +193,32 @@ void slab_free(mem_allocator_t* a, void* addr) { o->next = r->c.first_free_obj; r->c.first_free_obj = o; r->n_free_objs++; - // TODO : if cache is empty, free it + + if (r->n_free_objs == region_size / a->types[i].obj_size) { + // region is completely unused, free it. + if (a->slabs[i].first_cache == r) { + a->slabs[i].first_cache = r->c.next_cache; + } else { + for (cache_t *it = a->slabs[i].first_cache; it->c.next_cache != 0; it = it->c.next_cache) { + if (it->c.next_cache == r) { + it->c.next_cache = r->c.next_cache; + break; + } + } + } + if (a->all_caches == r) { + a->all_caches = r->next_region; + } else { + for (cache_t *it = a->all_caches; it->next_region != 0; it = it->next_region) { + if (it->next_region == r) { + it->next_region = r->next_region; + break; + } + } + } + a->free_fun(r->region_addr); + add_free_region_descriptor(a, r); + } return; } } @@ -194,15 +226,15 @@ void slab_free(mem_allocator_t* a, void* addr) { // otherwise the block was directly allocated : look for it in regions. a->free_fun(addr); - ASSERT(a->all_regions != 0); + ASSERT(a->all_other_regions != 0); - if (a->all_regions->region_addr == addr) { - cache_t *r = a->all_regions; + if (a->all_other_regions->region_addr == addr) { + cache_t *r = a->all_other_regions; ASSERT(r->is_a_cache == 0); - a->all_regions = r->next_region; + a->all_other_regions = r->next_region; add_free_region_descriptor(a, r); } else { - for (cache_t *i = a->all_regions; i->next_region != 0; i = i->next_region) { + for (cache_t *i = a->all_other_regions; i->next_region != 0; i = i->next_region) { if (i->next_region->region_addr == addr) { cache_t *r = i->next_region; ASSERT(r->is_a_cache == 0); |