Re: [fuse-devel] multi-threaded Fuse and Writes

[Michael M. <Mic...@cs...>]

On 27/05/11 21:53, Nikolaus Rath wrote:
> John Haechten <jha...@pu...> writes:
>> Is there an option for FUSE to enforce Sequential WRITE ?
> 
> If you mean per file: browse the ml archive, I think this was discussed
> a few days/weeks ago.

Yes - I previously submitted a patch which could provide a filesystem
threading option where by operations taking the struct fuse_file_info
parameter are serialised but everything else is threaded as before.

My motivation for that patch was exactly for filesytems like mine and [I
guess] John's where threads accelerates parallel access to different
resources, but non-sequential reads or writes to a single resource have
a penalty.  I also checked mp3fs and found it currently opts for single
threaded access but could benefit from the threading model I patched on
systems with more than 1 CPU (which is most computers these days).

Also when using the highlevel API, as soon as you opt for threaded
operations, you can get non-sequential access even from a purely serial
reader or writer and this can't be fixed without going to the lowlevel
API.

Working with the highlevel FUSE API is certainly easier and while my
patch may not have been perfect, I think there is a little bit more
evidence that a the threading option I proposed could be beneficial to
FUSE filesystem writers.

Regards,

Mike