Hello,
I tested the patch with two workloads on 2x466 Celeron/128MB. Btw. I couldn't
trigger the SMP race with these tests. What kind of workload is needed?

* make -j30 bzImage

* bonnie++ -s 512
[amlaukka@stellar tmp]$ bon_csv2txt <stellar.pp.htv.fi-2.4.0-test7-pre4-vm
Version  1.00  ------Sequential Output------ --Sequential Input---Random-
               -Per Chr- --Block-- -Rewrite- -Per Chr- --Block----Seeks--
Machine        MB K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP  /sec %CP
   Unknown     512  6236 87 11975  18 4242   8  5217  66  9623  10   nan 
   -2147483648
               ------Sequential Create------ --------RandomCreate--------
               -Create-- --Read--- -Delete-- -Create-- --Read----Delete--
files:max:min /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP
Unknown 30    129  98 +++++  90  5484  99   130  98 +++++  97   642  96

For comparison:
[amlaukka@stellar tmp]$ bon_csv2txt <stellar.pp.htv.fi-2.3.99-pre6-3
Version  1.00 ------Sequential Output------ --Sequential Input---Random-
              -Per Chr- --Block-- -Rewrite- -Per Chr- --Block----Seeks--
Machine       MB K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP  /sec%CP
   Unknown    256 7484 100 24077  40  7602  15  7005  90 22186  29   nan
-2147483648
              ------Sequential Create------ --------RandomCreate--------
              -Create-- --Read--- -Delete-- -Create-- --Read----Delete--
files:max:min /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec%CP
Unknown 30    125  99 +++++  96  6043 100   127  99 +++++  99   602 90

I also logged vmstat, date and cat /proc/zoneinfo every seconds. These logs
are available at 

http://www.cs.helsinki.fi/Aki.Laukkanen/log.1.bz2 (make)
http://www.cs.helsinki.fi/Aki.Laukkanen/log.2.bz2 (bonnie++)

/proc/zoneinfo is a silly hack. Hopefully it's somewhat useful. See attached
patch. I haven't done much analyzing on these logs although there seems to
be gaps of several tens of seconds (indicating burstiness).


-- 
D.