Where have the bugs gone?

The incoming bug rate over the past 7 days is much lower than the past 14 days. Maybe this is a blip. But commits to trunk have begun to use 8-digit bug numbers that do not reference entries in bugs.mysql.com. I think something has changed but nothing has been announced. I like bugs.mysql.com. We all benefit by sharing bug reports and I contributed a lot of content. It is also easy to search (use "site:bugs.mysql.com" on google searches).

Assuming there was a change maybe it doesn't matter to most community members.

This happens when you don't have a condition variable

Did Windows NT not have condition variables? This might be an artifact of that. It shows what happens when you don't have a condition variable.

stop_ibuf_merges:

        mutex_enter(&fil_system->mutex);

        space = fil_space_get_by_id(id);

        if (space != NULL) {
                space->stop_ibuf_merges = TRUE;

                if (space->n_pending_ibuf_merges == 0) {
                        mutex_exit(&fil_system->mutex);
                        count = 0;
                        goto try_again;
                } else {
                        if (count > 5000) {
                                ut_print_timestamp(stderr);
                                fputs("  InnoDB: trying to delete tablespace ", stderr);
                                ut_print_filename(stderr, space->name);
                        }

                        mutex_exit(&fil_system->mutex);

                        os_thread_sleep(20000);
                        count++;

                        goto stop_ibuf_merges;
                }

So long kernel mutex

If you are willing to look there are a few good changes in trunk for InnoDB. A frequent source of mutex contention in InnoDB, kernel_mutex, has been replaced with a rw-lock for the transaction system (see trx_sys_struct), two mutexes in srv_sys_struct and possibly other mutexes and rw-locks. The dulint struct has been replaced with a native 8-byte int. All of these changes should make InnoDB more efficient for workloads with a large number of concurrent transactions and help with bug 49169.

I wish there were a better to track changes in InnoDB. Right now my tools are luck and recursive diff.