Re: cp(1) of large files is causing 100% CPU utilization and poor transfer

From: Matthias Apitz <guru_at_unixarea.de>
Date: Sat, 2 Jan 2021 19:28:21 +0100
El día sábado, enero 02, 2021 a las 05:06:05p. m. +0000, Rick Macklem escribió:

> Just fyi, I've reproduced the problem.
> All I did was create a 20Gbyte file
> on UFS on a slow (4Gbyte or RAM,
> slow spinning disk) laptop.
> (The UFS file system is just what the installer creates these days.)
> 
> cp still hasn't finished and is definitely
> taking a looott longer than dd did.
> 
> I'll start drilling down later to-day.
> 
> I'll admit doing lots of testing of copy_file_range(2)
> with large sparse files, but I may have missed testing
> a large non-sparse file.
> 
> rick
> ps: I've added Kostik and Kirk to the cc.

As the problem seems to be clear now, should I still file a PR?
I'm happy to do so.

	matthias



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Received on Sat Jan 02 2021 - 17:28:25 UTC

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