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IDS Forum
RE: Mutex - guard ?
Posted By: Paul Watson
Date: Monday, 8 September 2014, at 11:07 a.m.
In Response To: Re: Mutex - guard ? (Fernando Nunes)
Like I say to sysadmins - test it and see what happens - such a trivial test
to undertake
> -----Original Message-----
> From: ids-bounces@iiug.org [mailto:ids-bounces@iiug.org] On Behalf Of
> Fernando Nunes
> Sent: Monday, September 08, 2014 10:05 AM
> To: ids@iiug.org
> Subject: Re: Mutex - guard ? [33726]
>
> Hmmmm... I find it relatively easy to understand if we put SMT-2 vs SMT-4.
> I find it much harder to understand off... But ok.
>
> On Mon, Sep 8, 2014 at 3:54 PM, Paul Watson <paul@oninit.com> wrote:
>
> > 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.
> >
> >
> >
> >
> **********************************************************
> *********************
> > 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...
>
> --047d7bd74a263d037405028f2431
>
>
> **********************************************************
> *********************
> 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 ?
Fernando Nunes -- Monday, 8 September 2014, at 11:05 a.m.
- RE: Mutex - guard ?
Paul Watson -- Monday, 8 September 2014, at 11:07 a.m.
- Re: Mutex - guard ?
Art Kagel -- Monday, 8 September 2014, at 11:08 a.m.
- Re: Mutex - guard ?
Marco Greco -- Monday, 8 September 2014, at 1:05 p.m.
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