Re: Question about Reiser4

H. Peter Anvin
2007-04-23T23:55:16Z

Theodore Tso wrote:
>
> One of the big problems of using a filesystem as a DB is the system
> call overheads. If you use huge numbers of tiny files, then each
> attempt read an atom of information from the DB takes three system
> calls --- an open(), read(), and close(), with all of the overheads in
> terms of dentry and inode cache.
>

Now, to be fair, there are probably a number of cases where
open/lseek/readv/close and open/lseek/writev/close would be worth doing
as a single system call. The big problem as far as I can see involves
EINTR handling; such a system call has serious restartability implications.

Of course, there are Ingo's syslets...

-hpa