Re: ULE/SCHED_SMP diff for 7.0

From: Dmitry Morozovsky <marck_at_rinet.ru>
Date: Wed, 18 Jul 2007 01:16:41 +0400 (MSD)
On Mon, 16 Jul 2007, Jeff Roberson wrote:

JR> http://people.freebsd.org/~jeff/ule.diff
JR> 
JR> This patch is scheduled for inclusion in 7.0.  I would like anyone who cares
JR> to run it to validate that it does not create any stability or performance
JR> regression over the existing ULE.  This patch replaces ULE with SCHED_SMP,
JR> which will now no longer exist as a seperate fork of ULE.
JR> 
JR> Briefly, this is still a very suitable scheduler for uniprocessor machines
JR> while providing stronger affinity and other performance improvements for
JR> multiprocessor machines.
JR> 
JR> Even "works for me!" type responses are welcome so I know roughly how many
JR> people have tested before I commit this close to release.

Works for me with MSI S420 lapton (core2duo T2400) on fresh -CURRENT/i386
CPU: Genuine Intel(R) CPU           T2400  _at_ 1.83GHz (1833.41-MHz 686-class CPU)

However, make -j3 buildworld buildkernel (trimmed GENERIC) time degraded by 7%:

marck_at_mck-s420:/var/tmp> ministat before after
x before
+ after
+------------------------------------------------------------------------------+
|   x                                                                    +     |
|   x                                                                    +     |
|x  x        x                                                      +    +    +|
||__MA____|                                                           |__A__|  |
+------------------------------------------------------------------------------+
    N           Min           Max        Median           Avg        Stddev
x   5         36.33         36.77         36.45        36.486    0.16637307
+   5         38.87         39.23         39.03        39.042    0.12774976
Difference at 95.0% confidence
        2.556 +/- 0.216322
        7.00543% +/- 0.59289%
        (Student's t, pooled s = 0.148324)

before = kernel with SCHED_4BSD, after = SCHED_ULE with your patchset. Both 
are without WITNESS/INVARIANTS.

Sincerely,
D.Marck                                     [DM5020, MCK-RIPE, DM3-RIPN]
------------------------------------------------------------------------
*** Dmitry Morozovsky --- D.Marck --- Wild Woozle --- marck_at_rinet.ru ***
------------------------------------------------------------------------
Received on Tue Jul 17 2007 - 19:16:52 UTC

This archive was generated by hypermail 2.4.0 : Wed May 19 2021 - 11:39:14 UTC