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Re: Commit messages and the move to git


On 19/11/2019 19:32, Eric S. Raymond wrote:
> Richard Earnshaw (lists) <Richard.Earnshaw@arm.com>:
>> I was looking at the reposurgeon code last night, and I think I can see what
>> the problem *might* be, but I haven't had time to produce a testcase.
>>
>> Some of our commits have mergeinfo that looks a bit like this:
>>
>> 202022-202023,202026,202028-202029,202036,202039-202041,202043-202044,202048-202049,202051-202056,202058-202061,202064-202065,202068-202071,202077,202079-202082,202084,202086-202088,202092-202104,202106-202113,202115-202119,202121,202124-202134,202139,202142-202146,202148-202150,202153-202154,202158-202159,202163-202165,202168,202172,202174,202179-202180,202184-202192,202195,202197,202202-202208,202225-202230,202232-202233,202237-202239,202242,202244-202245,202247,202250-202251,202258-202264,202266,202269,202271-202275,202279,202281-202282,202284,202286,202289-202292,202296-202299,202301-202302,202305,202309,202311-202323,202327-202335,202337,202339,202343-202346,202350,202352,202356-202357,202359-202360,202363-202371,202373-202374,202377,202379-202382,202384,202389,202391-202395,202398-202407,202409,202411,202416-202418,202421
>>
>> which is a massive long list with a number of holes in it.
>>
>> But I suspect the holes are really commits to other branches and that in the
>> above describes a linear chain along one branch.  If so, rather than
>> producing links to each subgroup (and perhaps dropping single non-list
>> elements, the description can be mapped back to a contiguous sequence of
>> commits down a branch and thus should really resolve to a single child being
>> used for the merge source.  At present, I think for the above we're seeing a
>> child reference created for each subrange in that list.
> 
> I have no doubt you are correct. Detecting such interrupted ranges ia
> foing to be...  interesting.
> 
>> Incidentally, the mergeinfo pass on the gcc repo is currently taking about 8
>> hours on my machine, that's 80-90% of the entire conversion time.  But it
>> might be related to the above.
> 
> You must be running the old Python code, there was on O(n**2) in that
> phase that has since been fixed. Try the Go code from
> https://gitlab.com/esr/reposurgeon; it is *much* faster.
> 

Nope, that was from running the go version from yesterday.  This one, to
be precise:  1ab3c514c6cd5e1a5d6b68a8224df299751ca637

This pass used to be very fast a couple of weeks back, but something
went in recently that's caused a major slowdown.

Oh, and I've been having problems with the ChangeLogs command as well.
It used to run fine on my machine (128G), but now it's started blowing
memory and taking my X server down.

R.

R.


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