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IDS Forum
Re: Mutex - guard ?
Posted By: Cesar Martins
Date: Tuesday, 9 September 2014, at 10:37 a.m.
In Response To: Re: Mutex - guard ? (Art Kagel)
Hi Art, Fernando , Paul,
Art , yes, the proc folding is off... we already get this few years ago.
I do not intend to keep this discussion... but I'm very glad about the
"rain" of messages saying "get out of smt-4" .
I already try convince the support team about this , without success...
so... .
Trying keep short :
We have lot of problem when we start to use this P7 (few years ago) and
even a IBM AIX expert become at the company to check our configuration,
because the system performance do not reach what the seller told (120%
faster than our previus P6 ... I prefer not say my opinion here about this
fact) .
At that time I've been "forced" to try make this environment perform as was
sold... we open PMRs , make a conference call with Informix support, try
some configurations, get AIX specialist... and at the end we stuck with
this configuration (recommended).
A year later of all this IBM publish A Technical White Paper : IBM
Informix on POWER7 Best Practices
https://www.ibm.com/developerworks/community/wikis/home?lang=en#!/wiki/W6461741bf7e8_47d7_89fc_a0a9233f3ca9/page/IBM%20Informix%20on%20POWER7
Quoting the page 12 :
"Recommendation
If you are most concerned about overall throughput for your Informix
server, use SMT4,
because using SMT4 can more fully utilize the core. While tests showed a
60% increase in
throughput, keep in mind that single-thread response time does not scale
linearly as more SMT
threads are used. If you want to optimize for response time, you can start
with SMT4 for the
increased throughput, but if you see single-thread response time suffer,
move to SMT2."
Like your guys, I try run out of SMT , but unfortunately IBM , someway,
always tell us to keep at SMT-4 .
I do not have autonomy , time and opportunity to try and prove the SMT is
"bad" for databases.... so.. there is... our database production running
into SMT-4 ..
That's all ...
2014-09-08 12:08 GMT-03:00 Art Kagel <art.kagel@gmail.com>:
> Another thing to look at is the processor folding when SMT is enabled. The
> machine will disable and enable SMT threads dynamically and that is costly.
> You need to turn that off for Informix. Whatever SMT level you choose has
> to be fixed to perform well.
>
> Art
>
> 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 Mon, Sep 8, 2014 at 10:54 AM, 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.
> >
> >
>
> --001a11c3bd5009886b05028f324f
>
>
>
> *******************************************************************************
> Forum Note: Use "Reply" to post a response in the discussion forum.
>
>
--047d7bdc9e28f3a3bb0502a2df52
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 ?
Art Kagel -- Monday, 8 September 2014, at 11:08 a.m.
- Re: Mutex - guard ?
Cesar Martins -- Tuesday, 9 September 2014, at 10:37 a.m.
- Re: Mutex - guard ?
Marco Greco -- Monday, 8 September 2014, at 1:05 p.m.
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