commit fd28754dd3dce0e00304825d531348414c0a354b Author: Nick Mathewson nickm@torproject.org Date: Sun Jan 12 12:26:45 2014 -0500

Actually release buffer freelists when handling OOM conditions.

Otherwise freeing buffers won't help for a little while. --- src/or/buffers.c | 9 +++++++-- src/or/buffers.h | 2 +- src/or/circuitlist.c | 13 +++++++++++++ 3 files changed, 21 insertions(+), 3 deletions(-)

diff --git a/src/or/buffers.c b/src/or/buffers.c index 856c9b6..352e60a 100644 --- a/src/or/buffers.c +++ b/src/or/buffers.c @@ -276,12 +276,14 @@ 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; @@ -315,6 +317,7 @@ 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; @@ -343,8 +346,10 @@ buf_shrink_freelists(int free_all) } done: enable_control_logging(); + return total_freed; #else (void) free_all; + return 0; #endif }

diff --git a/src/or/buffers.h b/src/or/buffers.h index 677d68d..b3b9003 100644 --- a/src/or/buffers.h +++ b/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); diff --git a/src/or/circuitlist.c b/src/or/circuitlist.c index 2e13541..ffb5e0c 100644 --- a/src/or/circuitlist.c +++ b/src/or/circuitlist.c @@ -1533,6 +1533,17 @@ circuits_handle_oom(size_t current_allocation) "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); if (current_allocation <= mem_target) @@ -1575,6 +1586,8 @@ 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),