Description of problem: Powertop reveals 20 interrupts from libata per second when there is no hard disk activity. It may be relevant that there are two (ide) optical drives on this system. I understand that hald-addon-storage polls the cd/dvd drives every couple of seconds, but this still seems like too many. Some data points: * Killing hald-addon-storage from powertop causes libata wakeups to drop to near-zero (0.2/second over 15 seconds). * Inserting an audio cd in each drive and then quitting kscd so that both drives are locked results in only around 2 interrupts/second from libata. * As an aside, this is better than kernel 2.6.23.1-49 which had typically 40 wakeups/second and around 3 wakeups / second even after killing hald-addon-storage. Based on the attached strace, below, I suspect that hald-addon-storage is polling the two optical drives in alternate seconds. Something like bug #204969 comment #1 may help synchronize the times that the two optical drives are polled. This would still leave the problem of hald-addon-storage causing 20 wakeups every time it polls is - whether this is due to some inefficiency or can't be helped, I don't know. Version-Release number of selected component (if applicable): hal-0.5.10-1 kernel-2.6.23.8-63
Created attachment 280311 [details] strace -tt of both hald-addon-storage processes with empty drives The strace output I've attached seems to actually have both drives being polled in the same second, unlike an earlier test I did not record, and contrary to my claim above. Still, there may be a way to better synchronize the polling or make it more efficient in terms of interrupts.
Created attachment 280331 [details] strace -tt of both hald-addon-storage processes with locked drives
*** This bug has been marked as a duplicate of 204969 ***