Re: [Sks-devel] sks (fast)build memory/cache problem

[John Clizbe]

Stephan Beyer wrote:
> On 01.07.2012 04:29, Stephan Beyer wrote:
>> Interestingly, if I take a look into merge.log now, I can see:
>> 
>> 2012-07-01 04:13:03 Fatal database error: Bdb.DBError("BDB2034 unable to
>> allocate memory for mutex; resize mutex region")
>> 2012-07-01 04:13:03 closing database...
> 
> I tried with bdb 5.3.
> Now I tried with bdb 5.1 and the effect is the same.

In sksconf add/adjust

pagesize:       128 # Use 64k pages for KDB
ptree_pagesize:  16 # Use  8K pages for PTree

BDB takes out a mutex lock on each page it's writing. BDB's default pagesize
is 512 bytes. Increasing the pagesize decreases the required number of mutexes.

When I was building KDB on a 1GB system, swapping occurred between 175000 &
200000 keys resulting in -n 7 for a 25k keys/file dump and -n 11 for 15k
keys/file dumps. I've never used fastbuild.

Once built, KDB and PTree may need BDB tuning parameters adjusted by DB_CONFIG
files.

-John