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Re: [RFC PATCH 1/4] name-rev: improve name_rev() memory usage

From
Jeff King <peff@peff.net>
Date
Mar 1, 2019, 18:44 UTC
Message-ID
<20190301184457.GE30847@sigill.intra.peff.net>
In-Reply-To
<20190301175024.17337-2-alban.gruin@gmail.com>
On Fri, Mar 01, 2019 at 06:50:21PM +0100, Alban Gruin wrote:
Show 5 quoted lines
> name_rev() is a recursive function.  For each commit, it allocates the
> name of its parents, and call itself.  A parent may not use a name for
> multiple reasons, but in any case, the name will not be released.  On a
> repository with a lot of branches, tags, remotes, and commits, it can
> use more than 2GB of RAM.

I don't know name-rev that well, so I didn't look super carefully at your patch. But if it's recursive in history, that's almost certainly going to be a problem for some histories on some platforms. We've had to de-recursify several other algorithms (e.g., "tag --contains") because of stack space issues.

Which isn't to say what you're doing here might not be separately useful, but just know that in the long run that's probably where we'd need to take this.

-Peff
Previous: Eric SunshineNext: Johannes Schindelin
Message 4 of 18 in “name-rev: improve memory usage”
  1. 0/4 name-rev: improve memory usageAlban Gruin, Mar 1, 2019
  2. 1/4 name-rev: improve name_rev() memory usageAlban Gruin, Mar 1, 2019
  3. Eric SunshineMar 1, 2019
  4. Jeff KingMar 1, 2019
  5. Johannes SchindelinMar 2, 2019
  6. 3/4 name-rev: check if a commit should be named before naming itAlban Gruin, Mar 1, 2019
  7. Eric SunshineMar 1, 2019
  8. Alban GruinMar 1, 2019
  9. Jeff KingMar 1, 2019
  10. 2/4 commit-list: add a function to check if a commit is in a listAlban Gruin, Mar 1, 2019
  11. 4/4 name-rev: avoid naming from a ref if it’s not a descendant of any commitAlban Gruin, Mar 1, 2019
  12. Eric SunshineMar 1, 2019
  13. Christian CouderMar 3, 2019
  14. Christian CouderMar 3, 2019
  15. Alban GruinMar 3, 2019
  16. Jeff KingMar 1, 2019
  17. Alban GruinMar 1, 2019
  18. Jeff KingMar 1, 2019

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