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From: Jonathan Tan <jonathantanmy@google.com>
To: peff@peff.net
Cc: gitster@pobox.com, jonathantanmy@google.com, git@vger.kernel.org
Subject: Re: [PATCH 2/3] index-pack: drop type_cas mutex
Date: Wed,  7 Oct 2020 13:09:06 -0700	[thread overview]
Message-ID: <20201007200906.1318031-1-jonathantanmy@google.com> (raw)
In-Reply-To: <20201007181943.GB1976631@coredump.intra.peff.net>

> The type_cas lock lost all of its callers in f08cbf60fe (index-pack:
> make quantum of work smaller, 2020-09-08), so we can safely delete it.
> The compiler didn't alert us that the variable became unused, because we
> still call pthread_mutex_init() and pthread_mutex_destroy() on it.
> 
> It's worth considering also whether that commit was in error to remove
> the use of the lock. Why don't we need it now, if we did before, as
> described in ab791dd138 (index-pack: fix race condition with duplicate
> bases, 2014-08-29)? I think the answer is that we now look at and assign
> the child_obj->real_type field in the main thread while holding the
> work_lock(). So we don't have to worry about racing with the worker
> threads.

Yeah - I probably should have made the change without removing the
compare-and-swap, and then removed the compare-and-swap in a subsequent
patch. Thanks for catching this.

  reply	other threads:[~2020-10-07 20:09 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-10-05 22:41 [ANNOUNCE] Git v2.29.0-rc0 Junio C Hamano
2020-10-05 23:33 ` Bryan Turner
2020-10-05 23:42 ` Randall S. Becker
2020-10-06  3:57 ` Martin Ågren
2020-10-06  6:08   ` Junio C Hamano
2020-10-07  9:54 ` Ævar Arnfjörð Bjarmason
2020-10-07 15:39 ` Jeff King
2020-10-07 15:45   ` Jeff King
2020-10-07 17:38     ` Junio C Hamano
2020-10-07 18:17       ` [PATCH 0/3] jt/threaded-inex-pack leftovers Jeff King
2020-10-07 18:19         ` [PATCH 1/3] index-pack: restore "resolving deltas" progress meter Jeff King
2020-10-07 18:50           ` Junio C Hamano
2020-10-07 18:19         ` [PATCH 2/3] index-pack: drop type_cas mutex Jeff King
2020-10-07 20:09           ` Jonathan Tan [this message]
2020-10-07 18:19         ` [PATCH 3/3] index-pack: stop mentioning find_unresolved_deltas() Jeff King
2020-10-07 18:41       ` [ANNOUNCE] Git v2.29.0-rc0 Jonathan Tan
2020-10-07 18:48         ` Jeff King
2020-10-07 20:16           ` [PATCH] index-pack: make get_base_data() comment clearer Jonathan Tan
2020-10-07 20:46             ` Junio C Hamano
2020-10-07 22:28 ` [ANNOUNCE] Git v2.29.0-rc0 Philippe Blain
2020-10-09 19:51 ` Randall S. Becker

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