Skip site navigation (1)Skip section navigation (2)
Date:      Tue, 30 May 2017 06:55:02 -0400
From:      "Chad J. Milios" <>
To:        Koichiro IWAO <>, freebsd-questions <>
Subject:   Re: Is it possible to use more than 1 CPUs during pkg create?
Message-ID:  <>
In-Reply-To: <>
References:  <>

Next in thread | Previous in thread | Raw E-Mail | Index | Archive | Help
> On May 30, 2017, at 5:33 AM, Koichiro IWAO <> wrote:
> Hi,
> is it possible to use more than 1 CPU cores during xz compression
> done in pkg create? I know XZ Utils in base system can use more
> than 1 CPUs if -T option given. I guess pkg internally calls APIs
> of XZ Utils. I think it is potentially possible.
> Or is it restricted to use only 1 CPU core for some reasons?
> --=20
> `whois | nkf -w`
> meta <>

Threading forfeits a bit of xz=E2=80=99s great compression ratio. An xz =
file created with -T greater than 1 will necessarily be some amount =
larger. Operating with just one thread achieves the maximal compression =
ratio. (The multiple compression threads fail to share the dictionaries =
they are currently building.)

When you are transferring GBytes to yourself once, use -T0. When you are =
compressing something one time that hundreds or thousands of people will =
potentially download and/or store, use -T1 (the default).=

Want to link to this message? Use this URL: <>