diff options
Diffstat (limited to 'erts/emulator/sys/common')
| -rw-r--r-- | erts/emulator/sys/common/erl_mmap.c | 142 | ||||
| -rw-r--r-- | erts/emulator/sys/common/erl_mmap.h | 11 | ||||
| -rw-r--r-- | erts/emulator/sys/common/erl_mseg.c | 6 |
3 files changed, 157 insertions, 2 deletions
diff --git a/erts/emulator/sys/common/erl_mmap.c b/erts/emulator/sys/common/erl_mmap.c index 1876398ec4..93a95e5eef 100644 --- a/erts/emulator/sys/common/erl_mmap.c +++ b/erts/emulator/sys/common/erl_mmap.c @@ -1039,7 +1039,7 @@ rbt_foreach_node(RBTree* tree, #endif } -#ifdef RBT_DEBUG +#if defined(RBT_DEBUG) || defined(HARD_DEBUG_MSEG) static RBTNode* rbt_prev_node(RBTNode* node) { RBTNode* x; @@ -1068,7 +1068,7 @@ static RBTNode* rbt_next_node(RBTNode* node) } return NULL; } -#endif /* RBT_DEBUG */ +#endif /* RBT_DEBUG || HARD_DEBUG_MSEG */ /* The API to keep track of a bunch of separated (free) segments @@ -2041,6 +2041,10 @@ int erts_mmap_in_supercarrier(void *ptr) return ERTS_MMAP_IN_SUPERCARRIER(ptr); } +#ifdef HARD_DEBUG_MSEG +static void hard_dbg_mseg_init(void); +#endif + void erts_mmap_init(ErtsMMapInit *init) { @@ -2233,6 +2237,10 @@ erts_mmap_init(ErtsMMapInit *init) #if !ERTS_HAVE_OS_MMAP mmap_state.no_os_mmap = 1; #endif + +#ifdef HARD_DEBUG_MSEG + hard_dbg_mseg_init(); +#endif } Eterm erts_mmap_info(Process* p) @@ -2494,3 +2502,133 @@ void test_it(void) } #endif /* FREE_SEG_API_SMOKE_TEST */ + + +#ifdef HARD_DEBUG_MSEG + +/* + * Debug stuff used by erl_mseg to check that it does the right thing. + * The reason for keeping it here is that we (ab)use the rb-tree code + * for keeping track of *allocated* segments. + */ + +typedef struct ErtsFreeSegDesc_fake_ { + /*RBTNode snode; Save memory by skipping unused size tree node */ + RBTNode anode; /* node in 'atree' */ + union { + char* start; + struct ErtsFreeSegDesc_fake_* next_free; + }u; + char* end; +}ErtsFreeSegDesc_fake; + +static ErtsFreeSegDesc_fake hard_dbg_mseg_desc_pool[10000]; +static ErtsFreeSegDesc_fake* hard_dbg_mseg_desc_first; +RBTree hard_dbg_mseg_tree; + +static erts_mtx_t hard_dbg_mseg_mtx; + +static void hard_dbg_mseg_init(void) +{ + ErtsFreeSegDesc_fake* p; + + erts_mtx_init(&hard_dbg_mseg_mtx, "hard_dbg_mseg"); + hard_dbg_mseg_tree.root = NULL; + hard_dbg_mseg_tree.order = ADDR_ORDER; + + p = &hard_dbg_mseg_desc_pool[(sizeof(hard_dbg_mseg_desc_pool) / + sizeof(*hard_dbg_mseg_desc_pool)) - 1]; + p->u.next_free = NULL; + while (--p >= hard_dbg_mseg_desc_pool) { + p->u.next_free = (p+1); + } + hard_dbg_mseg_desc_first = &hard_dbg_mseg_desc_pool[0]; +} + +static ErtsFreeSegDesc* hard_dbg_alloc_desc(void) +{ + ErtsFreeSegDesc_fake* p = hard_dbg_mseg_desc_first; + ERTS_ASSERT(p || !"HARD_DEBUG_MSEG: Out of mseg descriptors"); + hard_dbg_mseg_desc_first = p->u.next_free; + + /* Creative pointer arithmetic to return something that looks like + * a ErtsFreeSegDesc as long as we don't use the absent 'snode'. + */ + return (ErtsFreeSegDesc*) ((char*)p - offsetof(ErtsFreeSegDesc,anode)); +} + +static void hard_dbg_free_desc(ErtsFreeSegDesc* desc) +{ + ErtsFreeSegDesc_fake* p = (ErtsFreeSegDesc_fake*) &desc->anode; + memset(p, 0xfe, sizeof(*p)); + p->u.next_free = hard_dbg_mseg_desc_first; + hard_dbg_mseg_desc_first = p; +} + +static void check_seg_writable(void* seg, UWord sz) +{ + UWord* seg_end = (UWord*)((char*)seg + sz); + volatile UWord* p; + ERTS_ASSERT(ERTS_IS_PAGEALIGNED(seg)); + ERTS_ASSERT(ERTS_IS_PAGEALIGNED(sz)); + for (p=(UWord*)seg; p<seg_end; p += (ERTS_INV_PAGEALIGNED_MASK+1)/sizeof(UWord)) { + UWord write_back = *p; + *p = 0xfade2b1acc; + *p = write_back; + } +} + +void hard_dbg_insert_mseg(void* seg, UWord sz) +{ + check_seg_writable(seg, sz); + erts_mtx_lock(&hard_dbg_mseg_mtx); + { + ErtsFreeSegDesc *desc = hard_dbg_alloc_desc(); + RBTNode *prev, *next; + desc->start = (char*)seg; + desc->end = desc->start + sz - 1; /* -1 to allow adjacent segments in tree */ + rbt_insert(&hard_dbg_mseg_tree, &desc->anode); + prev = rbt_prev_node(&desc->anode); + next = rbt_next_node(&desc->anode); + ERTS_ASSERT(!prev || anode_to_desc(prev)->end < desc->start); + ERTS_ASSERT(!next || anode_to_desc(next)->start > desc->end); + } + erts_mtx_unlock(&hard_dbg_mseg_mtx); +} + +static ErtsFreeSegDesc* hard_dbg_lookup_seg_at(RBTree* tree, char* start) +{ + RBTNode* x = tree->root; + + while (x) { + ErtsFreeSegDesc* desc = anode_to_desc(x); + if (start < desc->start) { + x = x->left; + } + else if (start > desc->start) { + ERTS_ASSERT(start > desc->end); + x = x->right; + } + else + return desc; + } + return NULL; +} + +void hard_dbg_remove_mseg(void* seg, UWord sz) +{ + check_seg_writable(seg, sz); + erts_mtx_lock(&hard_dbg_mseg_mtx); + { + ErtsFreeSegDesc* desc = hard_dbg_lookup_seg_at(&hard_dbg_mseg_tree, (char*)seg); + ERTS_ASSERT(desc); + ERTS_ASSERT(desc->start == (char*)seg); + ERTS_ASSERT(desc->end == (char*)seg + sz - 1); + + rbt_delete(&hard_dbg_mseg_tree, &desc->anode); + hard_dbg_free_desc(desc); + } + erts_mtx_unlock(&hard_dbg_mseg_mtx); +} + +#endif /* HARD_DEBUG_MSEG */ diff --git a/erts/emulator/sys/common/erl_mmap.h b/erts/emulator/sys/common/erl_mmap.h index 6cb51fb0b4..106459f872 100644 --- a/erts/emulator/sys/common/erl_mmap.h +++ b/erts/emulator/sys/common/erl_mmap.h @@ -110,4 +110,15 @@ Eterm erts_mmap_info(struct process*); # define ERTS_HAVE_OS_MMAP 1 #endif +/*#define HARD_DEBUG_MSEG*/ +#ifdef HARD_DEBUG_MSEG +# define HARD_DBG_INSERT_MSEG hard_dbg_insert_mseg +# define HARD_DBG_REMOVE_MSEG hard_dbg_remove_mseg +void hard_dbg_insert_mseg(void* seg, UWord sz); +void hard_dbg_remove_mseg(void* seg, UWord sz); +#else +# define HARD_DBG_INSERT_MSEG(SEG,SZ) +# define HARD_DBG_REMOVE_MSEG(SEG,SZ) +#endif + #endif /* ERL_MMAP_H__ */ diff --git a/erts/emulator/sys/common/erl_mseg.c b/erts/emulator/sys/common/erl_mseg.c index c65973b3be..13f8069cf5 100644 --- a/erts/emulator/sys/common/erl_mseg.c +++ b/erts/emulator/sys/common/erl_mseg.c @@ -1356,6 +1356,7 @@ erts_mseg_alloc_opt(ErtsAlcType_t atype, UWord *size_p, Uint flags, const ErtsMs ERTS_DBG_MA_CHK_THR_ACCESS(ma); seg = mseg_alloc(ma, atype, size_p, flags, opt); ERTS_MSEG_UNLOCK(ma); + HARD_DBG_INSERT_MSEG(seg, *size_p); return seg; } @@ -1370,6 +1371,8 @@ erts_mseg_dealloc_opt(ErtsAlcType_t atype, void *seg, UWord size, Uint flags, const ErtsMsegOpt_t *opt) { ErtsMsegAllctr_t *ma = ERTS_MSEG_ALLCTR_OPT(opt); + + HARD_DBG_REMOVE_MSEG(seg, size); ERTS_MSEG_LOCK(ma); ERTS_DBG_MA_CHK_THR_ACCESS(ma); mseg_dealloc(ma, atype, seg, size, flags, opt); @@ -1390,10 +1393,13 @@ erts_mseg_realloc_opt(ErtsAlcType_t atype, void *seg, { ErtsMsegAllctr_t *ma = ERTS_MSEG_ALLCTR_OPT(opt); void *new_seg; + + HARD_DBG_REMOVE_MSEG(seg, old_size); ERTS_MSEG_LOCK(ma); ERTS_DBG_MA_CHK_THR_ACCESS(ma); new_seg = mseg_realloc(ma, atype, seg, old_size, new_size_p, flags, opt); ERTS_MSEG_UNLOCK(ma); + HARD_DBG_INSERT_MSEG(new_seg, *new_size_p); return new_seg; } |