Merge remote-tracking branch 'public/bug10169_023' into bug10169_024

src/or/buffers.c

@@ -244,12 +244,13 @@ static INLINE chunk_t *
 chunk_grow(chunk_t *chunk, size_t sz)
 {
   off_t offset;
+  size_t memlen_orig = chunk->memlen;
   tor_assert(sz > chunk->memlen);
   offset = chunk->data - chunk->mem;
   chunk = tor_realloc(chunk, CHUNK_ALLOC_SIZE(sz));
   chunk->memlen = sz;
   chunk->data = chunk->mem + offset;
-  total_bytes_allocated_in_chunks += (sz - chunk->memlen);
+  total_bytes_allocated_in_chunks += CHUNK_ALLOC_SIZE(sz) - CHUNK_ALLOC_SIZE(memlen_orig);
   return chunk;
 }
 
@@ -274,12 +275,14 @@ preferred_chunk_size(size_t target)
 }
 
 /** Remove from the freelists most chunks that have not been used since the
- * last call to buf_shrink_freelists(). */
-void
+ * last call to buf_shrink_freelists().   Return the amount of memory
+ * freed. */
+size_t
 buf_shrink_freelists(int free_all)
 {
 #ifdef ENABLE_BUF_FREELISTS
   int i;
+  size_t total_freed = 0;
   disable_control_logging();
   for (i = 0; freelists[i].alloc_size; ++i) {
     int slack = freelists[i].slack;
@@ -313,6 +316,7 @@ buf_shrink_freelists(int free_all)
         chunk_t *next = chunk->next;
         tor_assert(total_bytes_allocated_in_chunks >= CHUNK_ALLOC_SIZE(chunk->memlen));
         total_bytes_allocated_in_chunks -= CHUNK_ALLOC_SIZE(chunk->memlen);
+        total_freed += CHUNK_ALLOC_SIZE(chunk->memlen);
         tor_free(chunk);
         chunk = next;
         --n_to_free;
@@ -330,18 +334,21 @@ buf_shrink_freelists(int free_all)
       }
       // tor_assert(!n_to_free);
       freelists[i].cur_length = new_length;
+      tor_assert(orig_n_to_skip == new_length);
       log_info(LD_MM, "Cleaned freelist for %d-byte chunks: original "
-               "length %d, kept %d, dropped %d.",
+               "length %d, kept %d, dropped %d. New length is %d",
                (int)freelists[i].alloc_size, orig_length,
-               orig_n_to_skip, orig_n_to_free);
+               orig_n_to_skip, orig_n_to_free, new_length);
     }
     freelists[i].lowest_length = freelists[i].cur_length;
     assert_freelist_ok(&freelists[i]);
   }
  done:
   enable_control_logging();
+  return total_freed;
 #else
   (void) free_all;
+  return 0;
 #endif
 }
 
@@ -579,6 +586,7 @@ static chunk_t *
 chunk_copy(const chunk_t *in_chunk)
 {
   chunk_t *newch = tor_memdup(in_chunk, CHUNK_ALLOC_SIZE(in_chunk->memlen));
+  total_bytes_allocated_in_chunks += CHUNK_ALLOC_SIZE(in_chunk->memlen);
   newch->next = NULL;
   if (in_chunk->data) {
     off_t offset = in_chunk->data - in_chunk->mem;

src/or/buffers.h

@@ -18,7 +18,7 @@ void buf_free(buf_t *buf);
 void buf_clear(buf_t *buf);
 buf_t *buf_copy(const buf_t *buf);
 void buf_shrink(buf_t *buf);
-void buf_shrink_freelists(int free_all);
+size_t buf_shrink_freelists(int free_all);
 void buf_dump_freelist_sizes(int severity);
 
 size_t buf_datalen(const buf_t *buf);

src/or/circuitlist.c

@@ -1674,6 +1674,17 @@ circuits_handle_oom(size_t current_allocation)
              "over-long queues. (This behavior is controlled by "
              "MaxMemInQueues.)");
 
+  {
+    const size_t recovered = buf_shrink_freelists(1);
+    if (recovered >= current_allocation) {
+      log_warn(LD_BUG, "We somehow recovered more memory from freelists "
+               "than we thought we had allocated");
+      current_allocation = 0;
+    } else {
+      current_allocation -= recovered;
+    }
+  }
+
   {
     size_t mem_target = (size_t)(get_options()->MaxMemInQueues *
                                  FRACTION_OF_DATA_TO_RETAIN_ON_OOM);
@@ -1717,6 +1728,8 @@ circuits_handle_oom(size_t current_allocation)
   } SMARTLIST_FOREACH_END(circ);
 
   clean_cell_pool(); /* In case this helps. */
+  buf_shrink_freelists(1); /* This is necessary to actually release buffer
+                              chunks. */
 
   log_notice(LD_GENERAL, "Removed "U64_FORMAT" bytes by killing %d circuits.",
              U64_PRINTF_ARG(mem_recovered),