diff options
| author | Doug Moore <dougm@rice.edu> | 2017-06-14 16:27:24 -0500 |
|---|---|---|
| committer | Dave Watson <davejwatson@fb.com> | 2017-06-16 08:53:36 -0700 |
| commit | 0b51f5892df0691fc7b3b947647222ab8e57dd54 (patch) | |
| tree | 1bfdd8c416aff9273d68c06bbcc883fd10ad4345 | |
| parent | 5c0e619f8492aae0f15ad84aa79a7ecc846c2ba6 (diff) | |
| download | libunwind-0b51f5892df0691fc7b3b947647222ab8e57dd54.tar.gz | |
Dwarf cache nodes are allocated in a round-robin fashion, despite the
'lru' prefix used in several data fields. Drop the unnecessary fields,
and just use a simple counter to track the next cache entry to be recycled.
| -rw-r--r-- | include/dwarf.h | 4 | ||||
| -rw-r--r-- | src/dwarf/Gparser.c | 13 |
2 files changed, 4 insertions, 13 deletions
diff --git a/include/dwarf.h b/include/dwarf.h index ab2f34bf..469964e4 100644 --- a/include/dwarf.h +++ b/include/dwarf.h @@ -273,7 +273,6 @@ dwarf_stackable_reg_state_t; typedef struct dwarf_reg_cache_entry { unw_word_t ip; /* ip this rs is for */ - unsigned short lru_chain; /* used for least-recently-used chain */ unsigned short coll_chain; /* used for hash collisions */ unsigned short hint; /* hint for next rs to try (or -1) */ unsigned short valid : 1; /* optional machine-dependent signal info */ @@ -346,8 +345,7 @@ typedef unsigned char unw_hash_index_t; struct dwarf_rs_cache { pthread_mutex_t lock; - unsigned short lru_head; /* index of lead-recently used rs */ - unsigned short lru_tail; /* index of most-recently used rs */ + unsigned short rr_head; /* index of least-recently allocated rs */ unsigned short log_size; unsigned short prev_log_size; diff --git a/src/dwarf/Gparser.c b/src/dwarf/Gparser.c index 6246b5ee..efbb5e07 100644 --- a/src/dwarf/Gparser.c +++ b/src/dwarf/Gparser.c @@ -583,13 +583,10 @@ dwarf_flush_rs_cache (struct dwarf_rs_cache *cache) cache->prev_log_size = cache->log_size; } - cache->lru_head = DWARF_UNW_CACHE_SIZE(cache->log_size) - 1; - cache->lru_tail = 0; + cache->rr_head = 0; for (i = 0; i < DWARF_UNW_CACHE_SIZE(cache->log_size); ++i) { - if (i > 0) - cache->links[i].lru_chain = (i - 1); cache->links[i].coll_chain = -1; cache->links[i].ip = 0; cache->links[i].valid = 0; @@ -681,12 +678,8 @@ rs_new (struct dwarf_rs_cache *cache, struct dwarf_cursor * c) unw_hash_index_t index; unsigned short head; - head = cache->lru_head; - cache->lru_head = cache->links[head].lru_chain; - - /* re-insert rs at the tail of the LRU chain: */ - cache->links[cache->lru_tail].lru_chain = head; - cache->lru_tail = head; + head = cache->rr_head; + cache->rr_head = (head + 1) & (cache->log_size - 1); /* remove the old rs from the hash table (if it's there): */ if (cache->links[head].ip) |