lmbench hangs with memsize set to > 2GiB

[Carsten Schlote]

Binary package hint: lmbench

lmbench:
  Installiert:3.0-a7-1
  Mögliche Pakete:3.0-a7-1
  Versions-Tabelle:
 *** 3.0-a7-1 0
        500 http://de.archive.ubuntu.com hardy/multiverse Packages
        100 /var/lib/dpkg/status

The memsize test hangs in an endless loop if started with >= 2GiB of memory seleted at lmbench_run prompt. With just 1000MB the test completed within some seconds. The proposed value on the prompt of about 2800MB caused problems and the memsize didn't complete within 1 hour.

[Gregory Fong (gvfong)]

I'm guessing that this probably only happens on 32-bit systems? That would be caused by lmbench scripts deciding that 70% is the right amount of memory to use, which is a problem when the max amount per process is 2GiB and you have considerably more than that.

Solution: don't try to use >2 GiB RAM on 32-bit systems. Considering the purpose to be able to avoid the cache affecting your test results, you don't really need to use that much anyway.