Re: [PATCH] Minor scheduler fix to get rid of skipping in xmms

[David Mosberger-Tang]

>>>>> On Wed, 10 Sep 2003 00:40:09 +0200, Andrew Morton <akpm@xxxxxxxx> said:

  Andrew> Steven Pratt <slpratt@xxxxxxxxxxxxxx> wrote:

  >> >ftp://ftp.kernel.org/pub/linux/kernel/people/akpm/patches/2.6/2.6.0-test4/2.6.0-test4-mm6/broken-out/sched-CAN_MIGRATE_TASK-fix.patch
  >> >
  >> This patch improves specjjb over test5 and has no real effect on
  >> any of kernbench, volanomark or specsdet.

  Andrew> Fine, it's a good fix.

Is it that simple?  My reading is that it will do very bad things,
e.g., to pipe roundtrip latency on SMP machines.  Something that the
O(1) scheduler has handled nicely so far.

My preference would have been to break affinity only in the presence
of a _persistent_ load imbalance of >> 1.  For example, it's perfectly
OK and indeed encouraged to run N tasks on one and the same CPU, if
those tasks are (almost) never runnable at the same time.

	--david
--
Interested in learning more about IA-64 Linux?  Try http://www.lia64.org/book/
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/