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Posted to java-user@lucene.apache.org by Reg <re...@gmail.com> on 2013/10/22 08:26:39 UTC
use MMapDirectory with tmpfs?
Hi there,
If I put Lucene segments on tmpfs and use MMapDirectory to access them,
would the kernel be so dumb to load the files from tmpfs to another copy of
file system cache before map it to the virtual address? Or it just maps
tmpfs to the virtual address directly? I tend to believe it's the later
but want to confirm with the experts.
Re: use MMapDirectory with tmpfs?
Posted by Reg <re...@gmail.com>.
Excellent! Thanks for the answer. In fact we did have to choose between
tmpfs and ramfs, and now I know which one is better for certain.
On Tue, Oct 22, 2013 at 12:21 AM, Uwe Schindler <uw...@thetaphi.de> wrote:
> Hi,
>
> E.g., the Linux kernel implementation of tmpfs (inspired by Solaris) is to
> work solely on virtual memory - RTFM:
> https://www.kernel.org/doc/Documentation/filesystems/tmpfs.txt
> This is the main difference between a stupid old ramfs (aka RAM disk) and
> tmpfs.
>
> Uwe
>
> -----
> Uwe Schindler
> H.-H.-Meier-Allee 63, D-28213 Bremen
> http://www.thetaphi.de
> eMail: uwe@thetaphi.de
>
>
> > -----Original Message-----
> > From: Reg [mailto:register9527@gmail.com]
> > Sent: Tuesday, October 22, 2013 8:27 AM
> > To: java-user@lucene.apache.org
> > Subject: use MMapDirectory with tmpfs?
> >
> > Hi there,
> >
> > If I put Lucene segments on tmpfs and use MMapDirectory to access them,
> > would the kernel be so dumb to load the files from tmpfs to another copy
> of
> > file system cache before map it to the virtual address? Or it just maps
> tmpfs
> > to the virtual address directly? I tend to believe it's the later but
> want to
> > confirm with the experts.
>
>
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> To unsubscribe, e-mail: java-user-unsubscribe@lucene.apache.org
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>
>
RE: use MMapDirectory with tmpfs?
Posted by Uwe Schindler <uw...@thetaphi.de>.
Hi,
E.g., the Linux kernel implementation of tmpfs (inspired by Solaris) is to work solely on virtual memory - RTFM: https://www.kernel.org/doc/Documentation/filesystems/tmpfs.txt
This is the main difference between a stupid old ramfs (aka RAM disk) and tmpfs.
Uwe
-----
Uwe Schindler
H.-H.-Meier-Allee 63, D-28213 Bremen
http://www.thetaphi.de
eMail: uwe@thetaphi.de
> -----Original Message-----
> From: Reg [mailto:register9527@gmail.com]
> Sent: Tuesday, October 22, 2013 8:27 AM
> To: java-user@lucene.apache.org
> Subject: use MMapDirectory with tmpfs?
>
> Hi there,
>
> If I put Lucene segments on tmpfs and use MMapDirectory to access them,
> would the kernel be so dumb to load the files from tmpfs to another copy of
> file system cache before map it to the virtual address? Or it just maps tmpfs
> to the virtual address directly? I tend to believe it's the later but want to
> confirm with the experts.
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