From: "Mattias Engdegård" <mattias.engdegard@gmail.com>
To: Eli Zaretskii <eliz@gnu.org>
Cc: emacs-devel@gnu.org
Subject: Re: last_marked array is now ifdef'ed away
Date: Sun, 15 Sep 2024 15:58:03 +0200 [thread overview]
Message-ID: <E668665C-48AA-45C7-8080-DEBA35E269B9@gmail.com> (raw)
In-Reply-To: <86o74pea7k.fsf@gnu.org>
15 sep. 2024 kl. 07.51 skrev Eli Zaretskii <eliz@gnu.org>:
> I'd need to see actual evidence for a shorter array, based on actual
> GC run of some data structure.
And I'd need to see actual evidence for a longer array, based on actual debugging cases.
But perhaps there is a way for both of us to be just slightly disappointed: what about gating the check with a flag? That way, the trace buffer is always compiled-in. It needs to be enabled by the user but that is straightforward and can be done on the command line, in Lisp, or in a debugger.
As expected the runtime cost is not quite as bad as keeping it on all the time – the branch is always correctly predicted – although still slower than I'd like, but it's the best I can do for now.
There is then no need to skimp on the trace buffer size since it only matters when actually enabled. (We could even make it dynamic, so you'd set it to a megabyte if the situation calls for that.)
And I have a patch ready.
next prev parent reply other threads:[~2024-09-15 13:58 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-09-07 6:05 last_marked array is now ifdef'ed away Eli Zaretskii
2024-09-12 9:19 ` Eli Zaretskii
2024-09-13 14:43 ` Mattias Engdegård
2024-09-13 15:21 ` Eli Zaretskii
2024-09-14 17:05 ` Mattias Engdegård
2024-09-14 17:30 ` Eli Zaretskii
2024-09-14 20:30 ` Mattias Engdegård
2024-09-15 5:51 ` Eli Zaretskii
2024-09-15 13:58 ` Mattias Engdegård [this message]
2024-09-15 14:21 ` Eli Zaretskii
2024-09-17 10:15 ` Mattias Engdegård
2024-09-17 13:22 ` Eli Zaretskii
2024-09-14 22:50 ` Stefan Kangas
2024-09-15 6:01 ` Eli Zaretskii
2024-09-16 18:07 ` Andrea Corallo
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