Re: [RFC PATCH 03/24] erofs: add Errno in Rust

[Gao Xiang]

On 2024/9/26 19:01, Ariel Miculas wrote:

..

> > I believe they basically equal to your `Unified size`s, so
> > the result is
> >
> > 			Your unified size
> > 	EROFS (LZ4HC,12,64k)  54.2
> > 	PuzzleFS compressed   53?
> > 	EROFS (DEFLATE,9,32k) 46.4
> >
> > That is why I used your 53 unified size to show EROFS is much
> > smaller than PuzzleFS.
> >
> > The reason why EROFS and SquashFS doesn't have the `Total Size`s
> > is just because we cannot store every individual chunk into some
> > seperate file.
>
> Well storing individual chunks into separate files is the entire point
> of PuzzleFS.
>
> > Currently, I have seen no reason to open arbitary kernel files
> > (maybe hundreds due to large folio feature at once) in the page
> > fault context.  If I modified `mkfs.erofs` tool, I could give
> > some similar numbers, but I don't want to waste time now due
> > to `open arbitary kernel files in the page fault context`.
> >
> > As I said, if PuzzleFS finally upstream some work to open kernel
> > files in page fault context, I will definitely work out the same
> > feature for EROFS soon, but currently I don't do that just
> > because it's very controversal and no in-tree kernel filesystem
> > does that.
>
> The PuzzleFS kernel filesystem driver is still in an early POC stage, so
> there's still a lot more work to be done.

I suggest that you could just ask FS/MM folks about this ("open
kernel files when reading in the page fault")  first.

If they say "no", I suggest please don't waste on this anymore.

Thanks,
Gao Xiang

> Regards,
> Ariel
>
> > Thanks,
> > Gao Xiang