From: Dominique Quatravaux <domq@google.com>
Date: Thu, 08 Mar 2012 11:41:57 GMT
Subject: Re: [PATCH 1/2] rebase -i: optimize the creation of the todo file
Message-ID: <CAJh6GrGcr3nOMR7Yrq7g8c-RgQ4FS_FrhcMb+w-nXQO2nic_rw@mail.gmail.com>
In-Reply-To: <CAJh6GrGch9JHYnGW+K-wxdX9wPRry4Lxi2ysTtt0g9FTF4ThTQ@mail.gmail.com>

On Thu, Mar 8, 2012 at 12:36 PM, Dominique Quatravaux <domq@google.com> wrote:
> On Thu, Mar 8, 2012 at 12:20 PM, Johannes Sixt <j.sixt@viscovery.net> wrote:
>> Am 3/8/2012 11:42, schrieb Dominique Quatravaux:
>>> +     shortsha1=$(echo $sha1 | cut -c1-7)
>>
>>> -             sha1=$(git rev-parse $shortsha1)
>>
>> Why do you call it "optimization" when you spend two or three subprocesses
>> instead of one?
>
> echo is a shell internal. "git rev-parse" is two processes just as
> "cut" and a pipe.

My mistake, strace git rev-parse revals that this is only one process.
Still, I think that saving a bunch of filesystem access beats saving
one fork() (one of the two processes in my patched version is a shell,
so no execve() there) but I admit I haven't benchmarked this.


-- 
  Dominique Quatravaux
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