Re: [Bug-tar] Use posix_fadvise to improve archive creation performance

[Joerg Schilling]

Paul Eggert <address@hidden> wrote:

> On 03/27/2017 07:02 AM, Carlo Alberto Ferraris wrote:
> > This is a PoC patch that improves archive creation performance at least in 
> > certain configurations
>
> What configuration performs poorly with sequential access? How much 
> improvement do you see with the patch, and why?

I doubt that such methods will help to speed up archiving. I did many tests 
with similar approaches with star since aprox. 1997 and I did never see any 
performance win on any modern OS.

There was one single OS where it helped to use unbufferede I/O: DG/UX.

I used O_DG_UNBUFFERED and a special selr written read function that could help 
to speed up star dramatically - but only on DG/UX.

Jörg

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