![]() | |||||||||||||
Messages in this thread |
On Sun, Nov 09 2003, Guillaume Chazarain wrote: > > A process has an assigned io nice level, anywhere from 0 to 20. Both of > > OK, I ask THE question : why not using the normal nice level, via > current->static_prio ? > This way, cdrecord would be RT even in IO, and nice -19 updatedb would have > a minimal impact on the system. I don't want to tie io prioritites to cpu priorities, that's a design decision. > > these end values are "special" - 0 means the process is only allowed to > > do io if the disk is idle, and 20 means the process io is considered > > So a process with ioprio == 0 can be forever starved. As it's not Yes > done this way for nice -19 tasks (unlike FreeBSD), wouldn't it be > safer to give a very long deadline to ioprio == 0 requests ? ioprio == 0 means idle IO. It follows from that that you can risk infinite starvation if other io is happening. Otherwise it would not be idle io :-) CFQ doesn't assign request deadlines. That would be another way of handling starvation. > Thanks for making something I have been dreaming of for a long time :) Me too :) -- Jens Axboe - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ | ||||||||||||
| Last update: 2005-03-22 12:58 [from the cache] ©2003-2008 | |||||||||||||