Possible scheduler (SCHED_ULE) bug?

[Jaime Bozza]

> > The additional information I have (over the PR) is that:
> > 1) Files over 64K cause the problem, not just larger files
> I thought it was over 1 MB or so. But maybe I'm wrong. ISTR that I
> couldn't trigger it with some images of around 70K.

I discovered it originally with a 72K file.  After some tests, I found a 63K file worked and a 65K file didn't.  When I get back into the office, I can test the actual boundary (65535, 65536, 65537, etc), but 64K seems pretty logical.

> > 2) switching over to SCHED_4BSD eliminates the problem - system no
> longer locks.
> I will have to test this. This is indeed interesting...
> 
> > 3) 7.2 amd64 doesn't have the problem - Tested a similar
> configuration and was not able to duplicate on amd64 at all.
> I can replicate this problem on FreeBSD 7.2/amd64 reliably.

I haven't tried larger files - Maybe the boundary is different on amd64?   Doing some quick tests right now, I was able to upload a 100MB file without a problem, but this is an AMD64 system with SMP, plus the filesystem is all ZFS, so there are too many things different.  I'll have to setup a system that closely mirrors the rest of my tests (UFS, ULE, no SMP, etc) before I can say I'm not having a problem there.

Jaime