[issue1556] many processes stuck in "hmrrcm", system unusable

[Hasso Tepper]

Steve O'Hara-Smith wrote:
> That's something I have never seen happening, even when I do
> have a high load of filesystem activity, discs running at 100% for
> extended periods while largeish trees get moved around. The system
> certainly gets sluggish under that kind of load but nowhere near as bad
> as that.

My experience is comparable with corecode's experience. Even moderate IO 
load makes my audio stutter, my prompts apps hang for some seconds time 
to time etc. It's HAMMER + AHCI. It's not a conncurrent IO issue we 
obviously have (due to lack of IO scheduler). Surprisingly my UFS + NATA 
machine performs much better in this regard.

Not to mention http://bugs.dragonflybsd.org/issue1502 which became 
showstopper for DragonFly + HAMMER deploying for me.


-- 
Hasso Tepper