* Andrew Morton <[EMAIL PROTECTED]> wrote: >> Yes, there are potential compatibility problems. Example: a machine >> with 100 busy httpd processes and suddenly a big gzip starts up from >> console or cron. [...]
On Thu, Apr 19, 2007 at 08:38:10AM +0200, Ingo Molnar wrote: > hmmmm. How about the following then: default to nice -10 for all > (SCHED_NORMAL) kernel threads and all root-owned tasks. Root _is_ > special: root already has disk space reserved to it, root has special > memory allocation allowances, etc. I dont see a reason why we couldnt by > default make all root tasks have nice -10. This would be instantly loved > by sysadmins i suspect ;-) > (distros that go the extra mile of making Xorg run under non-root could > also go another extra one foot to renice that X server to -10.) I'd further recommend making priority levels accessible to kernel threads that are not otherwise accessible to processes, both above and below user-available priority levels. Basically, if you can get SCHED_RR and SCHED_FIFO to coexist as "intimate scheduler classes," then a SCHED_KERN scheduler class can coexist with SCHED_OTHER in like fashion, but with availability of higher and lower priorities than any userspace process is allowed, and potentially some differing scheduling semantics. In such a manner nonessential background processing intended not to ever disturb userspace can be given priorities appropriate to it (perhaps even con's SCHED_IDLEPRIO would make sense), and other, urgent processing can be given priority over userspace altogether. I believe root's default priority can be adjusted in userspace as things now stand somewhere in /etc/ but I'm not sure of the specifics. Word is somewhere in /etc/security/limits.conf -- wli - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/