Re: Odd (slow) RAID performance

[Bill Davidsen <davidsen@tmr.com>]

Neil Brown wrote:
> On Friday December 8, neilb@suse.de wrote:
>   
>> I have measured very slow write throughput for raid5 as well, though
>> 2.6.18 does seem to have the same problem.  I'll double check and do a
>> git bisect and see what I can come up with.
>>     
>
> Correction... it isn't 2.6.18 that fixes the problem.  It is compiling
> without LOCKDEP or PROVE_LOCKING.  I remove those and suddenly a
> 3 drive raid5 is faster than a single drive rather than much slower.
>
> Bill:  Do you have LOCKDEP or PROVE_LOCKING enabled in your .config ??
>   
I have to check tomorrow, I'm using the Fedora kernel (as noted in the 
first post on this) rather than one I built, just so others could verify 
my results as several have been kind enough to do. Have to run, but I 
will check tomorrow or Monday morning early at the latest.

-- 
bill davidsen <davidsen@tmr.com>
  CTO TMR Associates, Inc
  Doing interesting things with small computers since 1979