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

[Bill Hacker <wbh@xxxxxxxxxxxxx>]

Alex Hornung (via DragonFly issue tracker) wrote:
> Alex Hornung <ahornung@gmail.com> added the comment:
>
> : Corecode's report is the only one we have, and we don't have a realistic
> : test scenario that measures when it happens or how much it happens. 
> This is not really true. Hasso has also been complaining about very bad 
> performance and even showed some test cases and results running dd in various 
> scenarios. I also notice quite a performance degradation, especially working 
> with git. git diff and checkout particularly take ages on hammer.
>
>
> : Before we have Matt, who can work full-time on clustering - the _purpose
> : of this project_ - digress for months on filesystem performance, can we
> : quantify the actual problem?
> To quantify the problem should be straight forward. As I mentioned before, 
> hasso did some of it, but in any case there are test programs (thinking dbench 
> or similar here, don't know if anyone of them is in pkgsrc) who can quantify it 
> easily.
> About clustering being the main goal... the original goal, as far as I know, 
> was to have a well performing SMP system. Right now our SMP performance isn't 
> exactly good. I know that the main page is now full of references to clustering 
> being *THE* goal, but what happened to the original goals?
>
> Cheers,
> Alex Hornung

Not to put too fine a point on it, but ISTR that HAMMER was originally a 
serendipitous target of opportunity *en route* to SMP and clustering.

That said, if HAMMER *does* need work, well.... surely the goal is not to 
cluster a problematic fs.

The woods are full of those already.

Bill Hacker