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From: "Ævar Arnfjörð Bjarmason" <avarab@gmail.com>
To: Konstantin Ryabitsev <konstantin@linuxfoundation.org>
Cc: Junio C Hamano <gitster@pobox.com>, git@vger.kernel.org
Subject: Re: The most efficient way to test if repositories share the same objects
Date: Fri, 23 Mar 2018 15:36:06 +0100	[thread overview]
Message-ID: <87lgeiyi3t.fsf@evledraar.gmail.com> (raw)
In-Reply-To: <179c3cf0-72bd-559a-1e00-b18ce97e8136@linuxfoundation.org>


On Fri, Mar 23 2018, Konstantin Ryabitsev wrote:

> On 03/22/18 17:44, Junio C Hamano wrote:
>> Wouldn't it be more efficient to avoid doing so one-by-one?
>> That is, wouldn't
>>
>> 	rev-list --max-parents=0 --all
>>
>> be a bit faster than
>>
>> 	for-each-ref |
>> 	while read object type refname
>> 	do
>> 		rev-list --max-parents=0 $refname
>> 	done
>>
>> I wonder?
>
> Yeah, you're right -- I forgot that we can pass --all. The check takes
> 30 seconds, which is a lot better than 12 hours. :) It's a bit heavy
> still, but msm kernel repos are one of the heaviest outliers, so let me
> try to run with this.
>
> Thanks for the suggestion!

Unless you have just one CPU core your script would probably benefit
from being wrapped in GNU parallel. I.e.:

    parallel 'stuff-to-do {}' ::: $(list-of-repos)

Or something similar.

      reply	other threads:[~2018-03-23 14:36 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-03-22 16:48 The most efficient way to test if repositories share the same objects Konstantin Ryabitsev
2018-03-22 19:20 ` Ævar Arnfjörð Bjarmason
2018-03-22 19:35   ` Junio C Hamano
2018-03-22 19:53     ` Ævar Arnfjörð Bjarmason
2018-03-22 21:32     ` Konstantin Ryabitsev
2018-03-22 21:44       ` Junio C Hamano
2018-03-23 13:57         ` Konstantin Ryabitsev
2018-03-23 14:36           ` Ævar Arnfjörð Bjarmason [this message]

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