Informix

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Spin locks

  • 1.  Spin locks

    Posted 10 days ago
    I am observing following spin locks

    Top spi where Num Loops are high


    Num Waits Num Loops Avg Loop/Wait Name

    206 8530238207 41408923.33 mtcb mutex_list_lock

    1741 242603370 139347.14 fast mutex, lockhash[705]

    29975 216380509 7218.7 class cl_lock, class = 0

    151370 172400295 1138.93 mutex lock, name = INH list

    708 64244429 90740.72 mutex lock, name = log

    456 57240374 125527.14 fast mutex, lockhash[713]

    5191 24317182 4684.49 pool po_lock, name = global

    1768 18331879 10368.71 mutex lock, name = hdr_AckQ

    7312 11225103 1535.16 mutex lock, name = RA_Q_List

    11223 9794411 872.71 fast mutex, 0:bf[1024] 0x100004 0x6a9cc0800

    5269 7072307 1342.25 shmcb sh_lock

    29 6582337 226977.14 mtcb tcb_queue_lock

    7923 3234747 408.27 mutex lock, name = INH list


    Top spi where Avg Loop/Wait are high


    Num Waits Num Loops Avg Loop/Wait Name

    206 8530238207 41408923.33 mtcb mutex_list_lock

    1 230001 230001 tcb lock, tid = 1617563

    1 230001 230001 tcb lock, tid = 1986214

    1 230001 230001 tcb lock, tid = 1987687

    1 230001 230001 fast mutex, 1:bhash[1085686]

    1 230001 230001 fast mutex, gfile gfd 193 ioq_lock

    29 6582337 226977.14 mtcb tcb_queue_lock

    1 209699 209699 tcb lock, tid = 1293

    1741 242603370 139347.14 fast mutex, lockhash[705]

    456 57240374 125527.14 fast mutex, lockhash[713]

    1 108491 108491 tcb lock, tid = 1984622

    9 920855 102317.22 mutex lock, name = ddh chain 66

    13 1275626 98125.08 fast mutex, 1:bf[1024] 0xf00013 0x8dbdf9000

    22 2015707 91623.05 fast mutex, 1:bf[1024] 0xf0001b 0x79fa91000

    708 64244429 90740.72 mutex lock, name = log

    3 232314 77438 tcb lock, tid = 1984772

    7 508710 72672.86 mutex lock, name = sapi.SYS

    2 125511 62755.5 tcb lock, tid = 1986623

    4 202322 50580.5 fast mutex, 1:bf[1024] 0xf00017 0x7effe7000

    2 96382 48191 tcb lock, tid = 520731

    5 230875 46175 mutex lock, name = pt_2034be

    33 1522983 46151 mutex lock, name = ddh chain 306

    1 42622 42622 tcb lock, tid = 1982447

    19 779106 41005.58 mutex lock, name = centry -142795858

    39 1445660 37068.21 mutex lock, name = ddh chain 377

    1 36329 36329 mutex lock, name = netnorm

    7 232499 33214.14 mutex lock, name = ddh chain 150

    2 56927 28463.5 tcb lock, tid = 1984520

    4 111357 27839.25 fast mutex, 0:bhash[417187]

    12 322959 26913.25 fast mutex, 1:bf[1024] 0xf00011 0x7d9546000

    7 187257 26751 tcb lock, tid = 1635

    54 1360596 25196.22 mutex lock, name = ddh chain 16

    1 24100 24100 mutex lock, name = netnorm

    53 1241493 23424.4 mutex lock, name = ddh chain 191

    10 231904 23190.4 mutex lock, name = smx free 4

    4 92510 23127.5 fast mutex, 1:bf[1024] 0xf00014 0x8dbf46000

    1 20388 20388 tcb lock, tid = 1984128

    9 178579 19842.11 fast mutex, 1:bf[1024] 0xf00011 0x7bff3b000

    110 2076765 18879.68 mutex lock, name = ddh chain 263

    3 54764 18254.67 lockfr2

    1 17647 17647 fast mutex, 1:bhash[2873136]

    4 70401 17600.25 tcb lock, tid = 1439

    7 122873 17553.29 fast mutex, 1:bf[1024] 0xf0001c 0x79fa9b000

    28 471668 16845.29 mutex lock, name = pt_f00025

    6 99858 16643 fast mutex, 1:bhash[2707146]

    1 16432 16432 fast mutex, 1:bhash[2932658]

    1 16404 16404 tcb lock, tid = 1987368

    1 16016 16016 fast mutex, 0:bf[1024] 0x201787 0x707677000

    50 798928 15978.56 fast mutex, 0:bf[1024] 0x2027c0 0x6a18d5000

    1 14366 14366 tcb lock, tid = 1986980

    14 200024 14287.43 fast mutex, 0:bf[1024] 0x2027d1 0x6ea44f000

    1 14203 14203 fast mutex, 1:bhash[319800]

    4 53812 13453 tcb lock, tid = 1984244

    1 13046 13046 tcb lock, tid = 517037

    18 232104 12894.67 mutex lock, name = netfree

    9 113765 12640.56 tcb lock, tid = 1987263

    99 1207692 12198.91 mutex lock, name = ddh chain 3

    18 216112 12006.22 mutex lock, name = centry 909291775

    1 10494 10494 fast mutex, 1:bf[1024] 0xf0000e 0x96fb2d000

    1768 18331879 10368.71 mutex lock, name = hdr_AckQ

    1 10329 10329 tcb lock, tid = 1986526

    3 30911 10303.67 tcb lock, tid = 1987656

    2 20192 10096 tcb lock, tid = 1986786

    1 10002 10002 tcb lock, tid = 1987685



    ------------------------------
    Khurram Shahzad
    ------------------------------


  • 2.  RE: Spin locks

    Posted 6 days ago
    I'd say almost all of these have a non-significant 'Num Waits' number, so these spin locks had not been waited for very frequently, and maybe even fewer of these waits were very expensive. Moreove we don't learn over which period of time those counts accumulated.

    Not seeing a real reason for worries from this alone.

    HTH,
     Andreas

    ------------------------------
    Andreas Legner
    ------------------------------