Re: high load, no bottleneck

[christos%zoulas.com@localhost (Christos Zoulas)]

On Sep 19,  6:41pm, manu%netbsd.org@localhost (Emmanuel Dreyfus) wrote:
-- Subject: Re: high load, no bottleneck

| Greg Oster <oster%cs.usask.ca@localhost> wrote:
| 
| > > sysctl to the rescue.
| > 
| > The appropriate 'bit to twiddle' is likely raidPtr->openings.
| > Increasing the value can be done while holding raidPtr->mutex.
| > Decreasing the value can also be done while holding raidPtr->mutex, but
| > will need some care if attempting to decrease it by more than the
| > number of outstanding IOs.
| 
| This suggests that in my problem, RAIDframe would be the bottleneck
| given too many concurent I/O sent by WAPBL. But how is it possible?
| Aren't WAPBL flushes serialized?
| 
| The change you sugest would be set by raidctl rather than sysctl, right?

I think so, because it should be per raid set and it should be persistent.

christos