| From: |
| Arjan van de Ven <arjan@linux.intel.com> |
| To: |
| linux-kernel@vger.kernel.org, torvalds@osdl.org |
| Subject: |
| [Patch 0/4] Reordering of functions, try 2 |
| Date: |
| Mon, 27 Feb 2006 16:23:45 +0100 |
| Cc: |
| akpm@osdl.org, ak@suse.de |
| Archive-link: |
| Article,
Thread
|
Hi,
This is the second posting of the function reorder patches.
I've run a series of lmbench (3.0) runs on the patches earlier today on
this set, with the following results (I'll discuss 2 runs, one with the
first 3 patches, and one with all patches)
These are descriptions of the results, since the full lmbench run is a
LOT of numbers; this is the summary of it
1) There is a whole class of tests where it just doesn't matter at all.
In this class are the cpu measurements of FPU ops/second but also the
RAM bandwidth tests and the like. This is fully understandable; these
tests go straight from userspace->hardware, kernel changes don't impact
these.
2) In the "processor/processes" group, 7 tests changed behavior, and the
average of these changes was a performance increase by 10% (!!). The
exception was the signal handling test, which decreased by 6%. This
actually made me feel good, since the original function list was based
on a profile run that didn't do signals much if at all.
The second run (with all 4 patches) showed some fluctuations here but on
average it was in the noise region. Exception to this was the stat test,
which lost half the gain from the first 3 patches. Here also the signals
test lost
3) In the latency group, the 3-patches run is again in the 10% gain
range. Here the 4-patches run shows an additional gain for several of
the tests in the 5% range and for example the af_unix test showed a loss
compared to the 3-patches run