threads / discuss / 28770

Out of memory error with git rebase

Subject: Out of memory error with git rebase

## tl;dr

4 messages between Oct 26, 2011 and Oct 31, 2011.

replies: 3people: 3as markdown or json

Hannu Koivisto· Oct 26, 2011, 09:21 UTC · lore

Hi,

If 'git rebase origin/master' dies with an out of memory error (probably due to a few of large binary files in the repository, the largest being ~300MB and ~1GB in total in one directory), which settings should be tweaked and how to get rid of the problem? I tried...

[pack]
        threads = 1
        windowMemory = 64M
        packSizeLimit = 512M

...based on some suggestions in the net but that was of no help.

I'm using git 1.7.5.1 in Cygwin and I also tried the latest master branch version (which behaved identically).

-- 
Hannu

Johannes Sixt· Oct 26, 2011, 10:55 UTC · re: Hannu Koivisto · lore

Re: Out of memory error with git rebase

Am 26.10.2011 11:21, schrieb Hannu Koivisto:

Show 5 quoted lines

> If 'git rebase origin/master' dies with an out of memory error
> (probably due to a few of large binary files in the repository, the
> largest being ~300MB and ~1GB in total in one directory), which
> settings should be tweaked and how to get rid of the problem?  I
> tried...

Try 'git rebase -m origin/master'. Without -m, rebase uses format-patch+am, i.e., assuming there are changes to the binary files that are to be rebased, a binary patch file would have to be generated and applied later. This is very likely where git bails out.

-- Hannes

Hannu Koivisto· Oct 31, 2011, 10:33 UTC · re: Johannes Sixt · lore

Re: Out of memory error with git rebase

Johannes Sixt <j6t@kdbg.org> writes:

Show 8 quoted lines

> Am 26.10.2011 11:21, schrieb Hannu Koivisto:
>> If 'git rebase origin/master' dies with an out of memory error
>> (probably due to a few of large binary files in the repository, the
>
> Try 'git rebase -m origin/master'. Without -m, rebase uses
> format-patch+am, i.e., assuming there are changes to the binary files
> that are to be rebased, a binary patch file would have to be generated
> and applied later. This is very likely where git bails out.

Thanks, -m seems to help, even though the large binary files are not touched by the rebased commits (instead, they are touched by the commits on top of which I'm rebasing).

>From the documentation I can't figure out any reason why one

wouldn't always want to use -m. Why is it not the default? I think it's pretty much impossible for ordinary users to figure out that they need -m in a situation like this.

-- 
Hannu

Junio C Hamano· Oct 31, 2011, 20:21 UTC · re: Hannu Koivisto · lore

Re: Out of memory error with git rebase

Hannu Koivisto <azure@iki.fi> writes:

> From the documentation I can't figure out any reason why one
> wouldn't always want to use -m.  Why is it not the default?  I
> think it's pretty much impossible for ordinary users to figure out
> that they need -m in a situation like this.

Because most people do not have too large binary blobs in the history, and at least when "rebase" was originally written, merge-based rebasing was way slower than patch-based one.