Re: ~500 megs cached yet 2.6.5 goes into swap hell

Paul Mackerras
2004-04-29T02:58:25Z

Andrew Morton writes:

> OK, a bit of fiddling does indicate that if a file is present on both
> client and server, and is modified on the client, the rsync client will
> indeed touch the pagecache pages twice. Does this describe the files which
> you're copying at all?

The client/server thing is a bit misleading, what matters is the
direction of the transfer. In the case I saw this morning, the G5 was
the sender. In any case I was using the -W switch, which tells it not
to use the rsync algorithm but just transfer the whole file. So I
believe that rsync on the G5 side was just reading the file through
once.

I have also noticed similar behaviour after doing a bk pull on a
kernel tree.

The really strange thing is that the behaviour seems to get worse the
more RAM you have. I haven't noticed any problem at all on my laptop
with 768MB, only on the G5, which has 2.5GB. (The laptop is still on
2.6.2-rc3 though, so I will try a newer kernel on it.)

Regards,
Paul.