RFC: copy_file_range(3)

[Alexander Leidinger]

Quoting Rick Macklem <rmacklem at uoguelph.ca> (from Wed, 23 Sep 2020  
01:18:18 +0000):

> Well, I ran some quick benchmarks using the attached programs, plus "cp" both
> before and with your copy_file_range() patch.
> copya - Does what I think your plan is above, with a limit of  
> 2Mbytes for "len".
> copyb -Just uses copy_file_range() with 128Mbytes for "len".
>
> I first created the sparse file with createsparse.c. It is  
> admittedly a worst case,
> creating alternating holes and data blocks of the minimum size supported by
> the file system. (I ran it on a UFS file system created with  
> defaults, so the minimum
> hole size is 32Kbytes.)

Not related to the topic of changing cp, but related to the topic of  
copy_file_range: does nullfs support (as in pass-through to the  
underlying FS) copy_file_range?

Bye,
Alexander.

-- 
http://www.Leidinger.net Alexander at Leidinger.net: PGP 0x8F31830F9F2772BF
http://www.FreeBSD.org    netchild at FreeBSD.org  : PGP 0x8F31830F9F2772BF
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