Peter Williams wrote:
I'm seeing some strange load balancing problems with this kernel. I
don't think that they're due to the smpnice patches as I've applied them
on a standard 2.6.15-rc5 kernel and the problem doesn't happen there.
The problem is (as I say) quite strange and (for me) very reproducible.
I have two programs (aspin and gsmiley) which I use to produce CPU hard
spinners for testing purposes. What I'm finding is that when I start
several copies of aspin load balancing goes as expected but when I
launch several copies of gsmiley they all go to the one CPU and stick
there like glue. (The most obvious difference between the two programs
is that aspin is just a command line tool while gsmiley is an X windows
program that spins a simley face and reports its own assessment of the
percentage of CPU it's getting.) The machine that I've seen this
problem is a hyper threading Pentium 4 and I suspect that it may be due
to the SCHED_MC changes which overlap SCHED_SMT a bit.
I'm trying to test this on a non hyper threading machine but the machine
has crashed (different kernel) while doing the build. I'll resume this
effort tomorrow but I thought that I should report the problem so that
others could comment.
Peter
PS SCHED_MC was configured in but I'll try it without tomorrow and
report the results.
Configuring SCHED_MC to "no" causes this problem to go away.
Peter
--
Peter Williams [email protected]
"Learning, n. The kind of ignorance distinguishing the studious."
-- Ambrose Bierce
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
