On Tue, 2 Nov 2010 22:01:20 +0800, Wu Fengguang <fengguang.wu@xxxxxxxxx> wrote: > It's interesting to know what value you plan to use for your > desktop/server systems and the rationals (is it based on any > testing results?). This is something that will likely require a great deal of research, thinking, and testing. I wish I could give you a better answer at the moment. I have read many opinions on this but have not seen enough evidence to suggest specific values. In the desktop case, it seems clear that the preferred value should be lower than the current default to preserve interactive performance (long latencies due to swapping is something that many desktop users complain about currently). I set swappiness to 10 on my own machines machines with good results, but mine is anything but a model case. I don't believe there is any direct need to touch the server kernel swappiness at the moment. > And why it's easier to do it in kernel (hope it's not because of > trouble communicating with the user space packaging team). Fear not, this is certainly not the case. We would simply like to be able to keep this our kernel configuration self-contained. We already have separate packages for various kernel flavors with their own configurations. Allowing us to tune swappiness from the configuration would keep things much cleaner. The other option would be to drop a file in /etc/sysctl.d from the kernel meta-package (e.g. linux-image-generic and linux-image-server). However, it would make little sense to do this without adding a dependency on procps to this package (although, admittedly, procps is in the default installation) which we would rather not do if possible. Furthermore, this spreads the kernel configuration across the system. In sum, it seems that configuring the default in the kernel itself is by far the most elegant way to proceed. Cheers, - Ben -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom policy in Canada: sign http://dissolvethecrtc.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>