Messages in this thread |  | | From | rwhron@earthlin ... | Date | Wed, 17 Oct 2001 00:48:39 -0400 | Subject | Re: VM test on 2.4.13-pre3aa1 (compared to 2.4.12-aa1 and 2.4.13-pre2aa1) |
| |
On Wed, Oct 17, 2001 at 04:31:03AM +0200, Andrea Arcangeli wrote: > I noticed that anotehr thing that changed between vanilla 2.4.13pre2 and > 2.4.13pre3 is the setting of page_cluster on machine with lots of ram. > > You'll now find the page_cluster set to 6, that means "1 << 6 << 12" > bytes will be paged in at each major fault, while previously only "1 << > 4 << 12" bytes were paged in. > > So I'd suggest to try again after "echo 4 > /proc/sys/vm/page-cluster" > to see if it makes any difference. > > Andrea
You Rule!
The tweak to page-cluster is basically magic for this test.
With page-cluster=4, the mp3blaster sputtered like 2.4.13pre2aa1. Better, but not beautiful.
Real beauty happens with page-cluster=2. There is virtually no sputter. And the wall clock time is a little better than 2.4.13pre2aa1!
I don't know what page-cluster size is best for everything, but 2.4.12aa1 (which was very good IMHO), sputtered about 10 seconds per iteration, and each iteration took 64 seconds.
2.4.13pre3aa1 with no sputters: 48 seconds.
Amazing!
Also, interactive "feel" is much better too. This test would really brutalize keyboard response. With 2.4.13-pre3aa1 and page-cluster=2, the box is still usable. (for more than listening to mp3's :))
page-cluster = 6
Averages for 10 mtest01 runs bytes allocated: 1236166246 User time (seconds): 2.299 System time (seconds): 2.951 Elapsed (wall clock) time: 41.969 Percent of CPU this job got: 12.00 Major (requiring I/O) page faults: 113.5 Minor (reclaiming a frame) faults: 302580.3
page-cluster = 4
Averages for 10 mtest01 runs bytes allocated: 1237529395 User time (seconds): 2.097 System time (seconds): 2.788 Elapsed (wall clock) time: 49.394 Percent of CPU this job got: 9.50 Major (requiring I/O) page faults: 120.3 Minor (reclaiming a frame) faults: 302914.1
page-cluster = 2
Averages for 10 mtest01 runs bytes allocated: 1239521689 User time (seconds): 2.051 System time (seconds): 2.785 Elapsed (wall clock) time: 47.878 Percent of CPU this job got: 9.80 Major (requiring I/O) page faults: 114.0 Minor (reclaiming a frame) faults: 303399.7
The wall clock time went up somewhat from page-cluster=6. Here is where we were before:
2.4.13-pre2aa1
Averages for 10 mtest01 runs bytes allocated: 1245184000 User time (seconds): 2.050 System time (seconds): 2.874 Elapsed (wall clock) time: 49.513 Percent of CPU this job got: 9.70 Major (requiring I/O) page faults: 115.6 Minor (reclaiming a frame) faults: 304781.9
2.4.12aa1
Averages for 10 mtest01 runs bytes allocated: 1253362892 User time (seconds): 2.099 System time (seconds): 2.823 Elapsed (wall clock) time: 64.109 Percent of CPU this job got: 7.50 Major (requiring I/O) page faults: 135.2 Minor (reclaiming a frame) faults: 306779.8
-- Randy Hron
- 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/
|  |