[prefetch commit] r356 - wiki

[codesite...@google.com]

Author: krzysztof.lichota
Date: Mon Aug 20 10:58:22 2007
New Revision: 356

Modified:
wiki/InitialDiskReorderingResults.wiki

Log:
Added conclusions from test 2.

Modified: wiki/InitialDiskReorderingResults.wiki
==============================================================================
--- wiki/InitialDiskReorderingResults.wiki (original)
+++ wiki/InitialDiskReorderingResults.wiki Mon Aug 20 10:58:22 2007
@@ -69,6 +69,7 @@
* dir_indexes turned off for root partition.
* Prefetching was turned on.
* 3-aggregation was not used, prefetch always used last trace (side effect of some other change).
+ * Results of manual reordering and no reordering for comparison were taken from test 1.

Test method:
* System boot time was measured by automatically running script when system boots (using ~/.kde/Autostart). The script recorded contents of /proc/uptime (first number is time since boot in seconds).
@@ -92,11 +93,13 @@
|| Stddev || 2.19 || 2.35 || 2.26 || 0.17 || -0.09 ||
|| min || 44 || 45.1 || 49.13 || 1.1 || 4.03 ||
|| max || 50.28 || 53.38 || 57.2 || 3.1 || 3.82 ||
-
+IO ticks:
|| IO ticks || Manual reordering || Automatic reordering || Without reordering || Automatic reordering - Manual reordering || Without reordering - Automatic reordering ||
|| Average || 17.38 || 18.17 || 21.84 || 0.79 || 3.68 ||
|| Stddev || 0.28 || 2.33 || 0.33 || 2.05 || -2 ||
|| min || 16.82 || 16.7 || 21.43 || -0.12 || 4.73 ||
|| max || 17.83 || 24.75 || 22.6 || 6.92 || -2.15 ||

-=== Conclusions ===
\ No newline at end of file
+=== Conclusions ===
+ * Automatic reordering is slightly worse than manual reordering (0.86s), but still 4.93s better than no reordering.
+ * Reordering time should be improved to be ready for widespread deployment.
\ No newline at end of file