Re: [PATCH 0/3] gitk: memory consumption improvements

From: Junio C Hamano <gitster@pobox.com>
Date: Nov 8, 2016, 21:37 UTC
Message-ID: <xmqqtwbhbql9.fsf@gitster.mtv.corp.google.com>
In-Reply-To: <de7cd593-0c10-4e93-1681-7e123504f5d5@jump-ing.de>

Markus Hitter <mah@jump-ing.de> writes:

Show 10 quoted lines

> List, Paul,
>
> after searching for a while on why Gitk sometimes consumes
> exorbitant amounts of memory I found a pair of minor issues and
> also a big one: the text widget comes with an unlimited undo
> manager, which is turned on be default. Considering that each line
> is inserted seperately, this piles up a huuuge undo stack ... for
> a read-only text widget. Simply turning off this undo manager
> saves about 95% of memory when viewing large commits (with tens of
> thousands of diff lines).

You made me laugh crazy hard while in a waiting room in a clinic yesterday with the cover letter; people around gave me a strange look but I couldn't help.

This is a single liner with the largest gain in the history of this project. Very well spotted.

Are all semi-modern Tcl/Tk in service have this -undo thing so that we can pass unconditionally to the text widget like the patch does?

If we had to do this conditionally, that robs the fun of "just adding 8 bytes to the source to reduce 1+GB memory consumption", but even if we had to go conditional, this is a great find.

Well done.