Re: [fuse-devel] PATCH: i_blksize tuning in inode.c

[Miklos S. <mi...@sz...>]

>   the current fuse kernel module, in the function fuse_change_attributes,
> the inode->i_blksize is currently hardcoded to PAGE_CACHE_SIZE. applications
> like `cp' refer this value from fstat() (as st_blksize) on the file and use
> that as the block size to do transfers. I feel this value should be
> configurable by the filesystem, with an uppler limit check upto the channel
> size and a lower limit check to PAGE_CACHE_SIZE.

Probably makes sense, yes.  

>   the attached diff does the same. it causes applications (like cp) itself
> to work on larger chunks. this reduces the number of requests going upto the
> filesystem and drastically improves performance with reduced context
> switches.

The patch is wrong, it won't even compile, since there's no st_blksize
member in attr.  And if HAVE_I_BLKSIZE is false (which is on all newer
kernels) the patch will not do anything, which isn't what you want
either.

Thanks,
Miklos