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Re: Sun Donated a Sun Fire T2000 to the PostgreSQL

From: Robert Lor <Robert(dot)Lor(at)Sun(dot)COM>
To: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Cc: Tatsuo Ishii <ishii(at)sraoss(dot)co(dot)jp>, pgsql-hackers(at)postgresql(dot)org, pgsql-performance(at)postgresql(dot)org
Subject: Re: Sun Donated a Sun Fire T2000 to the PostgreSQL
Date: 2006-07-22 03:05:28
Message-ID: 44C195F8.9010409@sun.com (view raw or flat)
Thread:
Lists: pgsql-hackerspgsql-performance
Tom Lane wrote:

>Also, it'd be interesting to count time spent holding shared lock
>separately from time spent holding exclusive.
>
>  
>
Tom,

Here is the break down between exclusive & shared LWLocks. Do the 
numbers look reasonable to you?

Regards,
-Robert

bash-3.00# time ./Tom_lwlock_acquire.d `pgrep -n postgres`
********** LWLock Count: Exclusive **********
             Lock Id            Mode           Count
     ControlFileLock       Exclusive               1
       FreeSpaceLock       Exclusive               9
          XidGenLock       Exclusive             202
     CLogControlLock       Exclusive             203
        WALWriteLock       Exclusive             203
    BgWriterCommLock       Exclusive             222
     BufFreelistLock       Exclusive             305
      BufMappingLock       Exclusive             305
       ProcArrayLock       Exclusive             405
    FirstLockMgrLock       Exclusive             670
       WALInsertLock       Exclusive            1616

********** LWLock Count: Shared **********
             Lock Id            Mode           Count
 CheckpointStartLock          Shared             202
     CLogControlLock          Shared             450
 SubtransControlLock          Shared             776
          XidGenLock          Shared            2020
       ProcArrayLock          Shared            3778
          SInvalLock          Shared            4040
      BufMappingLock          Shared           40838

********** LWLock Time: Exclusive **********
             Lock Id   Combined Time (ns)
     ControlFileLock                 8301
       FreeSpaceLock                80590
     CLogControlLock              1603557
    BgWriterCommLock              1607122
     BufFreelistLock              1997406
          XidGenLock              2312442
      BufMappingLock              3161683
    FirstLockMgrLock              5392575
       ProcArrayLock              6034396
       WALInsertLock             12277693
        WALWriteLock            324869744

********** LWLock Time: Shared **********
             Lock Id   Combined Time (ns)
     CLogControlLock              3183788
 SubtransControlLock              6956229
          XidGenLock             12012576
          SInvalLock             35567976
       ProcArrayLock             45400779
      BufMappingLock            300669441
 CheckpointStartLock           4056134243


real    0m24.718s
user    0m0.382s
sys     0m0.181s



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