Messages in this thread |  | | Subject | Re: Feedback on preemptible kernel patch | From | Robert Love <> | Date | 09 Sep 2001 17:26:08 -0400 |
| |
On Sun, 2001-09-09 at 17:07, Arjan Filius wrote: > I tried 2.4.10-pre4+preempt+this-patch. > Just booted up, and don't notice anything unusual.
very good so far...
> I found i do anly have a '#define HIGHMEM_DEBUG 1' in > ./include/asm/highmem.h, which is default in 2.4.10-pre4.
OK, then no problem there.
> Booting up, X, compiling kernel.. no problems.
good...
> For speed, i DO notice other processes seem not to wait on that one > programm which has much disk-access, so the (real) sluggish feeling has > gone. This is however with the preempt patch, and the ctx_sw_ patch below > seems only to affect stability in positive sense.
_GREAT_ ... now, the reason I asked if you notice any new slowdowns is exactly what you seem to realize: I feared the ctx_sw patch may cause obvious slowdown. This could be because the ctw_on/offs are in the wrong place, and causing much to much locking.
It seems like you notice no problems, and I am happy.
I am glad to hear this news, I am going to take a look at highmem's code and then integrate a final solution into the preemption patch.
> Can you advice what and how to test performance/latency? > The grafics/statistics on the websites you named are impressive..
Sure, you can run dbench <ftp://samba.org/pub/tridge/dbench/> try it with around 16 threads (dbench -16). You might also want to try playing an mp3 in the background during this. Notice it should not have large skips (one user reporting 3s skipps dropping to 0.5s and 0s).
You can run the audio latency test <http://www.gardena.net/benno/linux/latencytest-0.42.tar.gz>, although I heard there are problems compiling it from some other preemption users.
Finally, simply time a kernel compile `time make dep clean bzImage' ...
We can use these for preemption enabled and disabled, highmem enabled and disabled, etc...
Thank you for your help,
-- Robert M. Love rml at ufl.edu rml at tech9.net
- 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/
|  |