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SubjectRe: [Bug 417] New: htree much slower than regular ext3
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

This seems consistent with readahead and AS disk io.

bill davidsen <>
CTO, TMR Associates, Inc
Doing interesting things with little computers since 1979.

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