Re: regression in multi-threaded git-pack-index
From: Junio C Hamano <hidden>
Date: 2016-06-15 22:56:27
Possibly related (same subject, not in this thread)
- 2016-06-15 · Re: regression in multi-threaded git-pack-index · Duy Nguyen <hidden>
- 2016-06-15 · Re: regression in multi-threaded git-pack-index · Thomas Rast <hidden>
- 2016-06-15 · Re: regression in multi-threaded git-pack-index · Jeff King <hidden>
- 2016-06-15 · Re: regression in multi-threaded git-pack-index · Jeff King <hidden>
- 2016-06-15 · Re: regression in multi-threaded git-pack-index · Jeff King <hidden>
Thomas Rast [off-list ref] writes:
Actually scratch that again. It *is* a stack overflow, except that this is a thread stack, for which the OS X defaults are 512kB apparently, as opposed to 2MB on linux. ... And indeed the following patch fixes it. Sounds like the delta unpacking needs a rewrite to support stackless operation. Sigh.
Yikes. Thanks for digging it to the bottom. I am not sure if I want to carry this patch in its current form, though. As this episode demonstrates, no default is good enough for everybody, and I am not sure if a configuration variable is a good way to go, either.
quoted hunk
diff --git i/builtin/index-pack.c w/builtin/index-pack.c index 6be99e2..f73291f 100644 --- i/builtin/index-pack.c +++ w/builtin/index-pack.c@@ -1075,13 +1075,17 @@ static void resolve_deltas(void) nr_dispatched = 0; if (nr_threads > 1 || getenv("GIT_FORCE_THREADS")) { init_thread(); + pthread_attr_t attr; + pthread_attr_init(&attr); + pthread_attr_setstacksize(&attr, 2*1024*1024); for (i = 0; i < nr_threads; i++) { - int ret = pthread_create(&thread_data[i].thread, NULL, + int ret = pthread_create(&thread_data[i].thread, &attr, threaded_second_pass, thread_data + i); if (ret) die(_("unable to create thread: %s"), strerror(ret)); } + pthread_attr_destroy(&attr); for (i = 0; i < nr_threads; i++) pthread_join(thread_data[i].thread, NULL); cleanup_thread();