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IDS Forum
RE: Mutex - guard ?
Posted By: Paul Watson
Date: Monday, 8 September 2014, at 10:54 a.m.
In Response To: Re: Mutex - guard ? (Fernando Nunes)
Off - total throughout when the machine is max'd out is the same but you can
drive the server harder sooner with SMT off. I was told the issue is AIX
SMT threading/scheduling doesn't play nice with the oninit processes. The
sysadmins always say it should be on and fight against turning it off and
will show you graphs showing the CPU are not that busy so it just can't be
an OS problem :) But if you can convince them to test it then ..... it
normally stays off - at least on a dedicated DB server.
Cheers
Paul
> -----Original Message-----
> From: ids-bounces@iiug.org [mailto:ids-bounces@iiug.org] On Behalf Of
> Fernando Nunes
> Sent: Monday, September 08, 2014 9:42 AM
> To: ids@iiug.org
> Subject: Re: Mutex - guard ? [33724]
>
> Off or SMT-2?!
>
> On Mon, Sep 8, 2014 at 3:13 PM, Paul Watson <paul@oninit.com> wrote:
>
> > You might want to turn off SMT completely, my testing with 11.7 and 6.1
> > showed greater throughput with SMT off
> >
> > Cheers
> > Paul
> >
> > > -----Original Message-----
> > > From: ids-bounces@iiug.org [mailto:ids-bounces@iiug.org] On Behalf Of
> > > Cesar Martins
> > > Sent: Monday, September 08, 2014 9:05 AM
> > > To: ids@iiug.org
> > > Subject: Re: Mutex - guard ? [33720]
> > >
> > > Hi David ,
> > >
> > > I've checked my history of emails and this is what I have :
> > >
> > > - There is no FIX , only a suggestion for workaround.
> > >
> > > - The problem occur with exclusive with Power7 processors using SMT-4
> > >
> > > configuration
> > >
> > > What they was explained , this is because of internal architecture of
P7
> > >
> > > in SMT-4 configuration.
> > >
> > > - workaround suggested (from IBM Support) , change the LPAR proc
> SMT-4
> > >
> > > to SMT-2
> > >
> > > - The ontat -g stk bellow
> > >
> > > - This is into version 11.50 FC9X6 , AIX 6.1
> > >
> > > stack for thread: 9063619 sqlexec
> > > base: 0x0700001cdecb7000
> > > len: 266240
> > >
> > > pc: 0x000000010003618c
> > > tos: 0x0700001cdecf21e0
> > > state: mutex wait
> > >
> > > vp: 49
> > >
> > > 0x000000010003618c (oninit)yield_processor_mvp
> > > 0x0000000100038b6c (oninit)mt_lock_wait
> > > 0x0000000100045a2c (oninit)mt_lock
> > > 0x0000000100d72958 (oninit)smi_network_io
> > > 0x000000010030a0fc (oninit)pstread
> > > 0x00000001002f1c00 (oninit)pst_rsread
> > > 0x00000001002fafd8 (oninit)rsread
> > > 0x00000001004c0c18 (oninit)fmread
> > > 0x0000000100668588 (oninit)readseq_single
> > > 0x0000000100668cd0 (oninit)gettupl
> > > 0x000000010066c488 (oninit)scan_next
> > > 0x0000000100d1182c (oninit)next_row
> > > 0x0000000100d1151c (oninit)get_first_row_from_producer
> > > 0x0000000100d10498 (oninit)hash_process_all_groups
> > > 0x0000000100d13f9c (oninit)group_open
> > > 0x000000010065f428 (oninit)filltemp
> > > 0x000000010066cd40 (oninit)scan_open
> > > 0x000000010066dc58 (oninit)materialize_viewtmp
> > > 0x000000010066dcdc (oninit)materialize_viewtmp
> > > 0x000000010066dcc8 (oninit)materialize_viewtmp
> > > 0x000000010066dcc8 (oninit)materialize_viewtmp
> > > 0x000000010040be94 (oninit)prepselect
> > > 0x000000010067ad80 (oninit)subqprep
> > > 0x000000010067b2f4 (oninit)exsubq
> > > 0x00000001005953d4 (oninit)geval
> > > 0x000000010075f308 (oninit)eval_projection_list
> > > 0x00000001007646c8 (oninit)dodmlrow
> > > 0x0000000100767254 (oninit)dodelupd
> > > 0x000000010041d030 (oninit)aud_dodelupd
> > > 0x000000010042593c (oninit)excommand
> > > 0x000000010023d4c0 (oninit)ip_evalsql
> > > 0x0000000100248f78 (oninit)runproc
> > > 0x0000000100243c7c (oninit)udrlm_spl_execute
> > > 0x0000000100ce98e4 (oninit)udrlm_exec_routine
> > > 0x0000000100581ea4 (oninit)udr_execute
> > > 0x00000001005bb768 (oninit)exroutine
> > > 0x00000001004240d0 (oninit)execproc
> > > 0x0000000100418120 (oninit)aud_execproc
> > > 0x0000000100426288 (oninit)excommand
> > > 0x000000010023d4c0 (oninit)ip_evalsql
> > > 0x0000000100248f78 (oninit)runproc
> > > 0x0000000100243c7c (oninit)udrlm_spl_execute
> > > 0x0000000100ce98e4 (oninit)udrlm_exec_routine
> > > 0x0000000100581ea4 (oninit)udr_execute
> > > 0x00000001003d8230 (oninit)exec_sysdbproc
> > > 0x0000000100cef16c (oninit)sqscb_cleanup
> > > 0x0000000100139a5c (oninit)destroy_session
> > > 0x00000001001f9894 (oninit)sqsetconerr
> > > 0x0000000100217148 (oninit)asf_recv
> > > 0x00000001002184c0 (oninit)_iread
> > > 0x000000010021883c (oninit)_igetint
> > > 0x000000010022451c (oninit)sqmain
> > > 0x000000010037c160 (oninit)listen_verify
> > > 0x000000010037a608 (oninit)spawn_thread
> > > 0x0000000100dd528c (oninit)startup
> > >
> > > 2014-09-05 18:12 GMT-03:00 david@smooth1.co.uk
> > > <david@smooth1.co.uk>:
> > >
> > > >
> > > > For interest (and the FAQ!) do you have an onstat -g stk for any of
the
> > > > holders or waiters of the mutex?
> > > >
> > > > And an APAR/release numbers when it was fixed?
> > > >
> > > > Marco/IBM can you confirm what the mutex is used for?
> > > >
> > > > Kind Regards,
> > > > David.
> > > >
> > > > > On 05 September 2014 at 18:33 Cesar Martins <
> > > > cesar.inacio.martins@gmail.com> wrote:
> > > > >
> > > > >
> > > > > Hi Fernando ,
> > > > >
> > > > > Yes!! and your question just help me remember a PMR open by my
> > self...
> > > > > after check my own history of PMR (because the limited IBM Support
> > site
> > > > not
> > > > > able to keep the history of your customers PMR) I already get into
> > this
> > > > > situation before and just forgot...
> > > > > ( 2011-10-17 - 40939,228,631)
> > > > >
> > > > > At my sysdbopen/close I collect lot of information of the session
and
> > > > one
> > > > > of them is selecting the sysnetworkio .
> > > > > The solution what work at that time is avoid access the
sysnetworkio
> > ,
> > > > but
> > > > > few months later I reactive this access because our "overhead" of
> > this
> > > > > parallel process was minimized for other reasons... now it's heavy
> > > > again,
> > > > > the problem just come back.
> > > > >
> > > > > Not sure, but as far I remember, this issue (sysnetworkio VS guard
> > > > mutex)
> > > > > was resolved at new versions... I just need upgrade my instance...
> > > > >
> > > > > Thank you!
> > > > >
> > > > > Bests Regards
> > > > > Cesar
> > > > >
> > > > > 2014-09-05 13:18 GMT-03:00 Fernando Nunes
> > > <domusonline@gmail.com>:
> > > > >
> > > > > > Do you have sysdbopen/sysdbclose() procedures?
> > > > > >
> > > > > > On Fri, Sep 5, 2014 at 4:21 PM, Cesar Martins <
> > > > > > cesar.inacio.martins@gmail.com> wrote:
> > > > > >
> > > > > > > Hi Art, Hi Marco,
> > > > > > >
> > > > > > > Hmm... make sense...
> > > > > > > sometimes we got nfs.lock too , but this I know is related
with
> > > > parallel
> > > > > > > open/close connections...
> > > > > > > But the "guard" too...is new for me....
> > > > > > >
> > > > > > > $ og wmx
> > > > > > >
> > > > > > > IBM Informix Dynamic Server Version 11.50.FC9X6 -- On-Line --
Up
> > 28
> > > > days
> > > > > > > 23:12:48 -- 183239776 Kbytes
> > > > > > >
> > > > > > > Mutexes with waiters:
> > > > > > > mid addr name holder lkcnt waiter
> > > > > > > waittime
> > > > > > > 3287 700001c8c0e0940 guard 311522329 0 311521906 0
> > > > > > >
> > > > > > > 311522235 0
> > > > > > >
> > > > > > > 311519249 1
> > > > > > >
> > > > > > > 311522173 0
> > > > > > >
> > > > > > > 311522502 0
> > > > > > >
> > > > > > > 311522306 0
> > > > > > >
> > > > > > > 311498199 0
> > > > > > >
> > > > > > > 311522330 0
> > > > > > >
> > > > > > > 311518371 0
> > > > > > >
> > > > > > > 311521699 0
> > > > > > >
> > > > > > > 311521847 0
> > > > > > >
> > > > > > > 311521991 1
> > > > > > >
> > > > > > > 311522751 0
> > > > > > >
> > > > > > > 311522203 0
> > > > > > >
> > > > > > > 311522325 1
> > > > > > >
> > > > > > > 311522657 0
> > > > > > >
> > > > > > > 311522623 0
> > > > > > >
> > > > > > > 311522521 0
> > > > > > >
> > > > > > > 2014-09-05 11:49 GMT-03:00 Marco Greco
> <marco@4glworks.com>:
> > > > > > >
> > > > > > > > On 05/09/14 15:46, Art Kagel wrote:
> > > > > > > > > I don't understand "Guard" mutex. Where are you seeing
> that?
> > > > > > > > >
> > > > > > > > > Art
> > > > > > > > >
> > > > > > > >
> > > > > > > > There is a 'guard' mutex.
> > > > > > > > It's used in ASF - I think it could be a bottleneck on lots
of
> > > > > > > connections
> > > > > > > > /
> > > > > > > > disconnections, but I haven't checked it out.
> > > > > > > >
> > > > > > > > > Art S. Kagel, Principal Consultant
> > > > > > > > > ASK Database Management
> > > > > > > > >
> > > > > > > > > Blog: http://informix-myview.blogspot.com/
> > > > > > > > >
> > > > > > > > > Disclaimer: Please keep in mind that my own opinions are
my
> > own
> > > > > > > opinions
> > > > > > > > > and do not reflect on the IIUG, nor any other organization
> > with
> > > > > > which I
> > > > > > > > am
> > > > > > > > > associated either explicitly, implicitly, or by inference.
> > > > Neither do
> > > > > > > > > those opinions reflect those of other individuals
affiliated
> > > > with any
> > > > > > > > > entity with which I am affiliated nor those of the
entities
> > > > > > themselves.
> > > > > > > > >
> > > > > > > > > On Fri, Sep 5, 2014 at 10:34 AM, Cesar Martins <
> > > > > > > > > cesar.inacio.martins@gmail.com> wrote:
> > > > > > > > >
> > > > > > > > >> Hi ,
> > > > > > > > >>
> > > > > > > > >> IFX 11.50 FC9X6 - AIX 6.1
> > > > > > > > >> + 1 read only RSS node
> > > > > > > > >>
> > > > > > > > >> We are running a bunch of parallel 4GL programs.
> > > > > > > > >> This programs start and finish very fast...
> > > > > > > > >>
> > > > > > > > >> We are getting wait at "guard" mutex ... and I found no
> > > > information
> > > > > > > > about
> > > > > > > > >> it .
> > > > > > > > >>
> > > > > > > > >> Any tips ?
> > > > > > > > >>
> > > > > > > > >> Cesar
> > > > > > > > >>
> > > > > > > > >> --20cf303ea812e58d860502525d63
> > > > > > > > >>
> > > > > > > > >>
> > > > > > > > >>
> > > > > > > > >>
> > > > > > > > >
> > > > > > > >
> > > > > > > >
> > > > > > >
> > > > > > >
> > > > > >
> > > > > >
> > > > >
> > > >
> > >
> **********************************************************
> > > *********************
> > > >
> > > > > > > > >> Forum Note: Use "Reply" to post a response in the
discussion
> > > > forum.
> > > > > > > > >>
> > > > > > > > >>
> > > > > > > > >
> > > > > > > > > --001a11c372be9ca97a0502528871
> > > > > > > > >
> > > > > > > > >
> > > > > > > > >
> > > > > > > >
> > > > > > > >
> > > > > > >
> > > > > > >
> > > > > >
> > > > > >
> > > > >
> > > >
> > >
> **********************************************************
> > > *********************
> > > >
> > > > > > > > > Forum Note: Use "Reply" to post a response in the
discussion
> > > > forum.
> > > > > > > > >
> > > > > > > > >
> > > > > > > >
> > > > > > > > --
> > > > > > > > Ciao,
> > > > > > > > Marco
> > > > > > > >
> > > > > > > >
> > > > > > >
> > > > > > >
> > > > > >
> > > > > >
> > > > >
> > > >
> > >
> __________________________________________________________
> > > ____________________
> > > >
> > > > > > > > Marco Greco /UK /IBM Standard disclaimers apply!
> > > > > > > >
> > > > > > > > Structured Query Scripting Language
> > > > http://www.4glworks.com/sqsl.htm
> > > > > > > > 4glworks http://www.4glworks.com
> > > > > > > > Informix on Linux http://www.4glworks.com/ifmxlinux.htm
> > > > > > > >
> > > > > > > >
> > > > > > > >
> > > > > > > >
> > > > > > >
> > > > > > >
> > > > > >
> > > > > >
> > > > >
> > > >
> > >
> **********************************************************
> > > *********************
> > > >
> > > > > > > > Forum Note: Use "Reply" to post a response in the discussion
> > > > forum.
> > > > > > > >
> > > > > > > >
> > > > > > >
> > > > > > > --047d7b41403683ecae0502530390
> > > > > > >
> > > > > > >
> > > > > > >
> > > > > > >
> > > > > >
> > > > > >
> > > > >
> > > >
> > >
> **********************************************************
> > > *********************
> > > >
> > > > > > > Forum Note: Use "Reply" to post a response in the discussion
> > forum.
> > > > > > >
> > > > > > >
> > > > > >
> > > > > > --
> > > > > > Fernando Nunes
> > > > > > Portugal
> > > > > >
> > > > > > http://informix-technology.blogspot.com
> > > > > > My email works... but I don't check it frequently...
> > > > > >
> > > > > > --001a11c3c3866ad617050253d296
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > >
> > > >
> > >
> **********************************************************
> > > *********************
> > > >
> > > > > > Forum Note: Use "Reply" to post a response in the discussion
> forum.
> > > > > >
> > > > > >
> > > > >
> > > > > --20cf303ea614ec5119050254ddbf
> > > > >
> > > > >
> > > > >
> > > >
> > >
> **********************************************************
> > > *********************
> > > >
> > > > > Forum Note: Use "Reply" to post a response in the discussion
forum.
> > > > >
> > > >
> > >
> > > --90e6ba614d4864b0d105028e4eb8
> > >
> > >
> > >
> **********************************************************
> > > *********************
> > > Forum Note: Use "Reply" to post a response in the discussion forum.
> >
> >
> >
> >
> **********************************************************
> *********************
> > Forum Note: Use "Reply" to post a response in the discussion forum.
> >
> >
>
> --
> Fernando Nunes
> Portugal
>
> http://informix-technology.blogspot.com
> My email works... but I don't check it frequently...
>
> --089e010d8dd6704cd805028ed0bb
>
>
> **********************************************************
> *********************
> Forum Note: Use "Reply" to post a response in the discussion forum.
Messages In This Thread
- Mutex - guard ?
Cesar Martins -- Friday, 5 September 2014, at 10:34 a.m.
- Re: Mutex - guard ?
Art Kagel -- Friday, 5 September 2014, at 10:46 a.m.
- Re: Mutex - guard ?
Marco Greco -- Friday, 5 September 2014, at 10:49 a.m.
- Re: Mutex - guard ?
Cesar Martins -- Friday, 5 September 2014, at 11:21 a.m.
- Re: Mutex - guard ?
Fernando Nunes -- Friday, 5 September 2014, at 12:18 p.m.
- Re: Mutex - guard ?
Cesar Martins -- Friday, 5 September 2014, at 1:33 p.m.
- Re: Mutex - guard ?
Fernando Nunes -- Friday, 5 September 2014, at 2:21 p.m.
- Re: Mutex - guard ?
david@smooth1.co.uk -- Friday, 5 September 2014, at 5:12 p.m.
- Re: Mutex - guard ?
Cesar Martins -- Monday, 8 September 2014, at 10:05 a.m.
- RE: Mutex - guard ?
Paul Watson -- Monday, 8 September 2014, at 10:13 a.m.
- Re: Mutex - guard ?
Art Kagel -- Monday, 8 September 2014, at 10:22 a.m.
- Re: Mutex - guard ?
Fernando Nunes -- Monday, 8 September 2014, at 10:41 a.m.
- RE: Mutex - guard ?
Paul Watson -- Monday, 8 September 2014, at 10:54 a.m.
- Re: Mutex - guard ?
Marco Greco -- Monday, 8 September 2014, at 1:05 p.m.
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