Re: [PATCH] sched: Fix adverse effects of NFS client on interactiveresponse
From: Peter Williams
Date: Wed Dec 21 2005 - 21:26:58 EST
Trond Myklebust wrote:
On Wed, 2005-12-21 at 08:36 -0500, Kyle Moffett wrote:
On Dec 21, 2005, at 08:21, Trond Myklebust wrote:
...and if you stick in a faster server?...
There is _NO_ fundamental difference between NFS and a local
filesystem that warrants marking one as "interactive" and the other
as "noninteractive". What you are basically saying is that all I/O
should be marked as TASK_NONINTERACTIVE.
Uhh, what part of disk/NFS/filesystem access is "interactive"? Which
of those sleeps directly involve responding to user-interface
events? _That_ is the whole point of the interactivity bonus, and
precisely why Ingo introduced TASK_NONINTERACTIVE sleeps; so that
processes that are not being useful for interactivity could be moved
away from TASK_NONINTERRUPTABLE, with the end result that the X-
server could be run at priority 0 without harming interactivity, even
during heavy *disk*, *NFS*, and *network* activity. Admittedly, that
may not be what some people want, but they're welcome to turn off the
interactivity bonuses via some file in /proc (sorry, don't remember
which at the moment).
Then have io_schedule() automatically set that flag, and convert NFS to
use io_schedule(), or something along those lines. I don't want a bunch
of RT-specific flags littering the NFS/RPC code.
This flag isn't RT-specific. It's used in the scheduling SCHED_NORMAL
tasks and has no other semantic effects.
Peter
--
Peter Williams pwil3058@xxxxxxxxxxxxxx
"Learning, n. The kind of ignorance distinguishing the studious."
-- Ambrose Bierce
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