On 7 Mar 2003, Alex Tomas wrote:
> The problem is that getdents(2) returns inodes out of order and
> du causes many head seeks. I tried to solve the problem by patch
> I included in. The idea of the patch is pretty simple: just try
> to sort dentries by inode number in readdir(). It works because
> inodes sits at fixed places in ext2/ext3. Please, look at results
> I just got:
Any change in the order of dentries returned is likely to run into problem
when seeking in a directory. Given that readdir() is usully followed by
either zero or many stat()s, perhaps when the first stat() comes along you
could pre-read the inodes in optimal order and cace them. However you
tuned the size of your sort should work exactly as well as the size of the
pre-read.
This seems consistent with readahead and AS disk io.
-- bill davidsen <davidsen@tmr.com> CTO, TMR Associates, Inc Doing interesting things with little computers since 1979.- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
This archive was generated by hypermail 2b29 : Sat Mar 15 2003 - 22:00:28 EST