I have a server with 4G of RAM running ReiserFS for everything that matters.
It has 2G of swap space free, but so far I have not seen swap usage go above 1.6M (so in normal use I could turn off swap entirely and expect not to see much difference). When it's under really heavy load (when I have a maintenance task involving a "find /" and there are lots of POP/IMAP clients hitting the server as well as mail delivery) and the load average gets to about 40, the "kswapd" kernel thread starts using excessive CPU time. It will stay on ~4% but have spikes of up to 45%!!! This is a two-processor machine so 45% CPU reported by top means 90% of a single CPU I guess. 90% of a 1.8GHz P4 CPU is a lot of CPU and I think that something is wrong. In the meager documentation in the kernel source kswapd is described as being involved in paging to disk. I don't think that this is what it is doing as there is no noticable paging activity (it generally has at least 600M of "buffers" so there is no real shortage of memory). Would the activity of kswapd be involved with ReiserFS in any way? What can I do to improve this situation? -- http://www.coker.com.au/selinux/ My NSA Security Enhanced Linux packages http://www.coker.com.au/bonnie++/ Bonnie++ hard drive benchmark http://www.coker.com.au/postal/ Postal SMTP/POP benchmark http://www.coker.com.au/~russell/ My home page
