Re: "du -b --files0-from=-" running out of memory

[Eric Blake]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

[adding the upstream coreutils list]

According to Barry Kelly on 11/23/2008 6:24 AM:
> I have a problem with du running out of memory.
> 
> I'm feeding it a list of null-separated file names via standard input,
> to a command-line that looks like:
> 
>   du -b --files0-from=-
> 
> The problem is that when du is run in this way, it leaks memory like a
> sieve. I feed it about 4.7 million paths but eventually it falls over as
> it hits the 32-bit address space limit.

That's because du must keep track of which files it has visited, so that
it can determine whether to recount or ignore hard links that visit a file
already seen.  The upstream ls source code was recently change to store
this information only for command line arguments, rather than every file
visited; I wonder if a similar change for du would make sense.

> 
> Now, I can understand why a du -c might want to exclude excess hard
> links to files, but that at most requires a hash table for device &
> inode pairs - it's hard to see why 4.7 million entries would cause OOM -
> and in any case, I'm not asking for a grand total.
> 
> Is there any other alternative to running e.g. xargs -0 du -b, possibly
> with a high -n <arg> to xargs to limit memory leakage?
> 
> -- Barry
> 

- --
Don't work too hard, make some time for fun as well!

Eric Blake             address@hidden
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.9 (Cygwin)
Comment: Public key at home.comcast.net/~ericblake/eblake.gpg
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org

iEYEARECAAYFAkkpZVEACgkQ84KuGfSFAYAFDwCfUXyduR1FfsDNn/RhzYAmy9lH
issAn0TQPQ0gQ6UKTkei1jDtVnxiQD5c
=0H69
-----END PGP SIGNATURE-----