Subject: Re: bug#79235: 31.0.50; Async checkin for Mercurial isn't async enough when checking in a patch

From: Sean Whitton <[email-masked]>
Date: Sat, 16 Aug 2025 19:43:50 +0100

Hello,

On Sat 16 Aug 2025 at 06:20pm +03, Dmitry Gutov wrote:

> On 16/08/2025 15:04, Sean Whitton wrote:
>> Thanks.  That's behaviour worth preserving.
>> How does the following plan seem to you:
>> - make the import command be the one that's done async, not the update
>> - leave a note saying if they are both potentially slow, we should do
>>    some messing about to make them both done asynchronously.  But don't
>>    do that yet in the absence of evidence.
>
> Yep, sounds good to me.
>
> So your measurements say that 'hg import' is often slower than the subsequent
> 'hg update'? Could be because of cold/warm disk cache, I suppose.

No measurements, I'm afraid.  It's just that when I implement
vc-async-checkin I didn't stop to consider which of the commands should
be asynchronous and just picked the one that runs later.

Actually stopping to think about it, creating a new commit object seems
likely to be more computationally intensive than moving the record of
where the tree is at.  This is fallible mostly because it's based on
understanding Git fairly well and assuming that Mercurial is just like
Git in this respect, which may or may not be true.

Thanks for the feedback, I'll work on it.

-- 
Sean Whitton