Large Pages on AIX
User reported that Informix 11.70FC4 on AIX 6.1 showed the message 'Shared memory segment will use large pages if available,' but svmon output indicated 16 MB large pages weren't actually being used (0 inuse). No resolution was provided in the thread; a follow-up question about general large pages guidelines was answered by others noting performance improvements on systems supporting them.
Auto-generated by DrWatson from the posts below — may be imperfect; read the full thread.
11.70FC4 on AIX 6.1
Were being told that we should enable LARGEPAGES for fast initialisation and
performance.
But, its not working for some reason:
The relevant variables are set
.
$ onstat -c | grep RESIDE# RESIDENT - Controls whether shared memory is resident.
RESIDENT 1$ env | grep IFX
IFX_LARGE_PAGES=1
$ onmode -ky ; oninit -v
And we get the will try to use large pages message:
20:07:06 IBM Informix Dynamic Server Started.
20:07:06 Requested shared memory segment size rounded from 133984KB to 262144KB
20:07:06 Shared memory segment will use large pages if available.
20:07:07 Segment locked: addr=700000010000000, size=268435456
20:07:08 VP pid=2032150 priority fixed at 60
Thu Apr 5 20:07:08 2012
20:07:08 Event alarms enabled. ALARMPROG =
'/opt/informix/INST1/scripts/alarmprogram.sh'
20:07:08 Dynamically allocated new virtual shared memory segment (size
1048576KB)
20:07:08 Memory sizes:resident:262144 KB, virtual:1058816 KB, no SHMTOTAL limit
20:07:08 Booting Language <c> from module <>
20:07:08 Loading Module <CNULL>
20:07:08 Booting Language <builtin> from module <>
20:07:08 Loading Module <BUILTINNULL>
20:07:14 DR: DRAUTO is 0 (Off)
20:07:14 DR: ENCRYPT_HDR is 0 (HDR encryption Disabled)
20:07:14 AIX MP latch code enabled
20:07:14 Requested shared memory segment size rounded from 548KB to 560KB
20:07:14 Dynamically allocated new message shared memory segment (size 560KB)
20:07:14 Memory sizes:resident:262144 KB, virtual:1059376 KB, no SHMTOTAL limit
20:07:14 Requested shared memory segment size rounded from 548KB to 560KB
20:07:14 Dynamically allocated new message shared memory segment (size 560KB)
20:07:14 Memory sizes:resident:262144 KB, virtual:1059936 KB, no SHMTOTAL limit
20:07:14 Fast poll pollset enabled.
20:07:14 IBM Informix Dynamic Server Version 11.70.FC4 Software Serial Number
AAA#B000000
20:07:15 IBM Informix Dynamic Server Initialized -- Shared Memory Initialized.
but it doesnt :
svmon -G
size inuse free pin virtual mmode
memory 31522816 22513142 9009674 22097181 2011105 Ded
pg space 131072 4806
work pers clnt other
pin 699341 0 0 934224
in use 2011105 0 38421
PageSize PoolSize inuse pgsp pin virtual
s 4 KB - 1367030 4806 1260061 1328609
m 64 KB - 42656 0 23344 42656
L 16 MB 4996 0 0 4996 0
Any ideas please? probably something really stupid and obvious.
Thanks
Neil
Are there any general guidelines that exist on when you should use large=20
pages?
Peter Logan
Senior Database Administrator
Phone: 616/878-8309
From: "NEIL TRUBY" <neil.truby@ardenta.com>
To: ids@iiug.org
Date: 04/05/2012 09:33 AM
Subject: Large Pages on AIX [26661]
Sent by: ids-bounces@iiug.org
11.70FC4 on AIX 6.1=20
We?re being told that we should enable LARGEPAGES for fast initialisation=20
and=20
performance.=20
But, it?s not working for some reason:=20
The relevant variables are set ?.=20
$ onstat -c | grep RESIDE=20# RESIDENT - Controls whether shared memory is resident.=20
RESIDENT 1=20$ env | grep IFX=20
IFX=5FLARGE=5FPAGES=3D1=20
$ onmode -ky ; oninit -v=20
And we get the ?will try to use large pages message?:=20
20:07:06 IBM Informix Dynamic Server Started.=20
20:07:06 Requested shared memory segment size rounded from 133984KB to=20
262144KB=20
20:07:06 Shared memory segment will use large pages if available.=20
20:07:07 Segment locked: addr=3D700000010000000, size=3D268435456=20
20:07:08 VP pid=3D2032150 priority fixed at 60=20
Thu Apr 5 20:07:08 2012=20
20:07:08 Event alarms enabled. ALARMPROG =3D=20
'/opt/informix/INST1/scripts/alarmprogram.sh'=20
20:07:08 Dynamically allocated new virtual shared memory segment (size=20
1048576KB)=20
20:07:08 Memory sizes:resident:262144 KB, virtual:1058816 KB, no SHMTOTAL=20
limit=20
20:07:08 Booting Language <c> from module <>=20
20:07:08 Loading Module <CNULL>=20
20:07:08 Booting Language <builtin> from module <>=20
20:07:08 Loading Module <BUILTINNULL>=20
20:07:14 DR: DRAUTO is 0 (Off)=20
20:07:14 DR: ENCRYPT=5FHDR is 0 (HDR encryption Disabled)=20
20:07:14 AIX MP latch code enabled=20
20:07:14 Requested shared memory segment size rounded from 548KB to 560KB=20
20:07:14 Dynamically allocated new message shared memory segment (size=20
560KB)=20
20:07:14 Memory sizes:resident:262144 KB, virtual:1059376 KB, no SHMTOTAL=20
limit=20
20:07:14 Requested shared memory segment size rounded from 548KB to 560KB=20
20:07:14 Dynamically allocated new message shared memory segment (size=20
560KB)=20
20:07:14 Memory sizes:resident:262144 KB, virtual:1059936 KB, no SHMTOTAL=20
limit=20
20:07:14 Fast poll pollset enabled.=20
20:07:14 IBM Informix Dynamic Server Version 11.70.FC4 Software Serial=20
Number=20
AAA#B000000=20
20:07:15 IBM Informix Dynamic Server Initialized -- Shared Memory=20
Initialized.=20
? but it doesn?t :=20
svmon -G=20
size inuse free pin virtual mmode=20
memory 31522816 22513142 9009674 22097181 2011105 Ded=20
pg space 131072 4806=20
work pers clnt other=20
pin 699341 0 0 934224=20
in use 2011105 0 38421=20
PageSize PoolSize inuse pgsp pin virtual=20
s 4 KB - 1367030 4806 1260061 1328609=20
m 64 KB - 42656 0 23344 42656=20
L 16 MB 4996 0 0 4996 0=20
Any ideas please? probably something really stupid and obvious.=20
Thanks=20
Neil=20
***************************************************************************=
****=20
Forum Note: Use "Reply" to post a response in the discussion forum.=20
>> Are there any general guidelines that exist on when you should use large pages? Peter Logan I've not seen any. I received a specific recommendation for our environment from IBM and an ex-colleague, based upon a PMR raised about performance. regards N
The seen to improve memory access times noticably on every system that
supports them (AIX, Solaris, & Linux IB).
Art
Art S. Kagel
Advanced DataTools (www.advancedatatools.com)
Blog: http://informix-myview.blogspot.com/
Disclaimer: Please keep in mind that my own opinions are my own opinions
and do not reflect on my employer, Advanced DataTools, 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 Thu, Apr 5, 2012 at 10:49 AM, Peter_Logan@spartanstores.com <
Peter_Logan@spartanstores.com> wrote:
> Are there any general guidelines that exist on when you should use large=20
> pages?
>
> Peter Logan
> Senior Database Administrator
> Phone: 616/878-8309
>
> From: "NEIL TRUBY" <neil.truby@ardenta.com>
> To: ids@iiug.org
> Date: 04/05/2012 09:33 AM
> Subject: Large Pages on AIX [26661]
> Sent by: ids-bounces@iiug.org
>
> 11.70FC4 on AIX 6.1=20
>
> We?re being told that we should enable LARGEPAGES for fast
> initialisation=20
> and=20
> performance.=20
>
> But, it?s not working for some reason:=20
>
> The relevant variables are set ?.=20
> $ onstat -c | grep RESIDE=20> # RESIDENT - Controls whether shared memory is resident.=20
> RESIDENT 1=20> $ env | grep IFX=20
> IFX=5FLARGE=5FPAGES=3D1=20>
> $ onmode -ky ; oninit -v=20>
> And we get the ?will try to use large pages message?:=20
>
> 20:07:06 IBM Informix Dynamic Server Started.=20
> 20:07:06 Requested shared memory segment size rounded from 133984KB to=20
> 262144KB=20
> 20:07:06 Shared memory segment will use large pages if available.=20
> 20:07:07 Segment locked: addr=3D700000010000000, size=3D268435456=20
> 20:07:08 VP pid=3D2032150 priority fixed at 60=20
>
> Thu Apr 5 20:07:08 2012=20
>
> 20:07:08 Event alarms enabled. ALARMPROG =3D=20
> '/opt/informix/INST1/scripts/alarmprogram.sh'=20
> 20:07:08 Dynamically allocated new virtual shared memory segment (size=20
> 1048576KB)=20
> 20:07:08 Memory sizes:resident:262144 KB, virtual:1058816 KB, no
> SHMTOTAL=20
> limit=20
> 20:07:08 Booting Language <c> from module <>=20
> 20:07:08 Loading Module <CNULL>=20
> 20:07:08 Booting Language <builtin> from module <>=20
> 20:07:08 Loading Module <BUILTINNULL>=20
> 20:07:14 DR: DRAUTO is 0 (Off)=20
> 20:07:14 DR: ENCRYPT=5FHDR is 0 (HDR encryption Disabled)=20
> 20:07:14 AIX MP latch code enabled=20
> 20:07:14 Requested shared memory segment size rounded from 548KB to
> 560KB=20
> 20:07:14 Dynamically allocated new message shared memory segment (size=20
> 560KB)=20
> 20:07:14 Memory sizes:resident:262144 KB, virtual:1059376 KB, no
> SHMTOTAL=20
> limit=20
> 20:07:14 Requested shared memory segment size rounded from 548KB to
> 560KB=20
> 20:07:14 Dynamically allocated new message shared memory segment (size=20
> 560KB)=20
> 20:07:14 Memory sizes:resident:262144 KB, virtual:1059936 KB, no
> SHMTOTAL=20
> limit=20
> 20:07:14 Fast poll pollset enabled.=20
> 20:07:14 IBM Informix Dynamic Server Version 11.70.FC4 Software Serial=20
> Number=20
> AAA#B000000=20
> 20:07:15 IBM Informix Dynamic Server Initialized -- Shared Memory=20
> Initialized.=20
>
> ? but it doesn?t :=20
>
> svmon -G=20
>
> size inuse free pin virtual mmode=20
> memory 31522816 22513142 9009674 22097181 2011105 Ded=20
> pg space 131072 4806=20
>
> work pers clnt other=20
> pin 699341 0 0 934224=20
> in use 2011105 0 38421=20
>
> PageSize PoolSize inuse pgsp pin virtual=20
> s 4 KB - 1367030 4806 1260061 1328609=20
> m 64 KB - 42656 0 23344 42656=20
> L 16 MB 4996 0 0 4996 0=20
>
> Any ideas please? probably something really stupid and obvious.=20
>
> Thanks=20
> Neil=20
>
>
> ***************************************************************************=
> ****=20
>
> Forum Note: Use "Reply" to post a response in the discussion forum.=20
>
>
>
>
*******************************************************************************
> Forum Note: Use "Reply" to post a response in the discussion forum.
>
>
--e89a8f3ba959914aa604bcf1642c
Hi Neil,
I already have this issues here.
You need to configure and active the pin memory :
Commands like :
(this command will take some time... allocating the memory)
# vmo -p -o lgpg_regions=6000 -o lgpg_size=16777216
# vmo -p -o v_pinshm=1
check the situation of memory with svmon (pin in use)... for example the
configuration what we use here (AIX 6.1)
The database is using large pages and is working with 180GB allocated
(to start don't take more of 30 seconds)
$ svmon -G -O unit=auto,pgsz=on
Unit: auto
--------------------------------------------------------------------------------
------
size inuse free pin virtual
available mmode
memory 210.00G 209.93G 75.0M 209.02G 198.69G
22.5M Ded
pg space 10.5G 0.95G
work pers clnt other
pin 191.10G 0K 0K 6.05G
in use 198.02G 0K 35.1M
PageSize PoolSize inuse pgsp pin virtual
s 4 KB - 8.01G 485.96M 7.85G 8.38G
m 64 KB - 15.3G 490.62M 14.6G 15.6G
L 16 MB 11944 174.75G 0K 186.62G 174.75G
Regards
Cesar
On 5/4/2012 10:33, NEIL TRUBY wrote:
> 11.70FC4 on AIX 6.1
>
> We're being told that we should enable LARGEPAGES for fast initialisation and
> performance.
>
> But, it's not working for some reason:
>
> The relevant variables are set ....
> $ onstat -c | grep RESIDE> # RESIDENT - Controls whether shared memory is resident.
> RESIDENT 1> $ env | grep IFX
> IFX_LARGE_PAGES=1>
> $ onmode -ky ; oninit -v>
> And we get the "will try to use large pages message":
>
> 20:07:06 IBM Informix Dynamic Server Started.
> 20:07:06 Requested shared memory segment size rounded from 133984KB to
> 262144KB
> 20:07:06 Shared memory segment will use large pages if available.
> 20:07:07 Segment locked: addr=700000010000000, size=268435456
> 20:07:08 VP pid=2032150 priority fixed at 60
>
> Thu Apr 5 20:07:08 2012
>
> 20:07:08 Event alarms enabled. ALARMPROG =
> '/opt/informix/INST1/scripts/alarmprogram.sh'
> 20:07:08 Dynamically allocated new virtual shared memory segment (size
> 1048576KB)
> 20:07:08 Memory sizes:resident:262144 KB, virtual:1058816 KB, no SHMTOTAL
> limit
> 20:07:08 Booting Language<c> from module<>
> 20:07:08 Loading Module<CNULL>
> 20:07:08 Booting Language<builtin> from module<>
> 20:07:08 Loading Module<BUILTINNULL>
> 20:07:14 DR: DRAUTO is 0 (Off)
> 20:07:14 DR: ENCRYPT_HDR is 0 (HDR encryption Disabled)
> 20:07:14 AIX MP latch code enabled
> 20:07:14 Requested shared memory segment size rounded from 548KB to 560KB
> 20:07:14 Dynamically allocated new message shared memory segment (size 560KB)
> 20:07:14 Memory sizes:resident:262144 KB, virtual:1059376 KB, no SHMTOTAL
> limit
> 20:07:14 Requested shared memory segment size rounded from 548KB to 560KB
> 20:07:14 Dynamically allocated new message shared memory segment (size 560KB)
> 20:07:14 Memory sizes:resident:262144 KB, virtual:1059936 KB, no SHMTOTAL
> limit
> 20:07:14 Fast poll pollset enabled.
> 20:07:14 IBM Informix Dynamic Server Version 11.70.FC4 Software Serial Number
> AAA#B000000
> 20:07:15 IBM Informix Dynamic Server Initialized -- Shared Memory
Initialized.
>
> ... but it doesn't:
>
> svmon -G
>
> size inuse free pin virtual mmode
> memory 31522816 22513142 9009674 22097181 2011105 Ded
> pg space 131072 4806
>
> work pers clnt other
> pin 699341 0 0 934224
> in use 2011105 0 38421
>
> PageSize PoolSize inuse pgsp pin virtual
> s 4 KB - 1367030 4806 1260061 1328609
> m 64 KB - 42656 0 23344 42656
> L 16 MB 4996 0 0 4996 0
>
> Any ideas please? probably something really stupid and obvious.
>
> Thanks
> Neil
>
>
>
*******************************************************************************
> Forum Note: Use "Reply" to post a response in the discussion forum.
>
I would suggest doing a 'bosboot' command to make sure that everything is
good after reboot.
Another way to check all is well:
Validate large page support is used with the following command:
vmstat -l 1
Note: The "alp" column is non-zero when the application is running.
On Thu, Apr 5, 2012 at 4:30 PM, Cesar Inacio Martins <
cesar_inacio_martins@yahoo.com.br> wrote:
> Hi Neil,
>
> I already have this issues here.
> You need to configure and active the pin memory :
>
> Commands like :
>
> (this command will take some time... allocating the memory)
>
> # vmo -p -o lgpg_regions=6000 -o lgpg_size=16777216
>
> # vmo -p -o v_pinshm=1
>
> check the situation of memory with svmon (pin in use)... for example the
> configuration what we use here (AIX 6.1)
> The database is using large pages and is working with 180GB allocated
> (to start don't take more of 30 seconds)
>
> $ svmon -G -O unit=auto,pgsz=on
> Unit: auto>
>
>
--------------------------------------------------------------------------------
------
>
> size inuse free pin virtual
> available mmode
> memory 210.00G 209.93G 75.0M 209.02G 198.69G
> 22.5M Ded
> pg space 10.5G 0.95G
>
> work pers clnt other
> pin 191.10G 0K 0K 6.05G
> in use 198.02G 0K 35.1M
>
> PageSize PoolSize inuse pgsp pin virtual
> s 4 KB - 8.01G 485.96M 7.85G 8.38G
> m 64 KB - 15.3G 490.62M 14.6G 15.6G
> L 16 MB 11944 174.75G 0K 186.62G 174.75G
>
> Regards
> Cesar
>
> On 5/4/2012 10:33, NEIL TRUBY wrote:
> > 11.70FC4 on AIX 6.1
> >
> > We're being told that we should enable LARGEPAGES for fast initialisation
> and
> > performance.
> >
> > But, it's not working for some reason:
> >
> > The relevant variables are set ....
> > $ onstat -c | grep RESIDE> > # RESIDENT - Controls whether shared memory is resident.
> > RESIDENT 1> > $ env | grep IFX
> > IFX_LARGE_PAGES=1> >
> > $ onmode -ky ; oninit -v> >
> > And we get the "will try to use large pages message":
> >
> > 20:07:06 IBM Informix Dynamic Server Started.
> > 20:07:06 Requested shared memory segment size rounded from 133984KB to
> > 262144KB
> > 20:07:06 Shared memory segment will use large pages if available.
> > 20:07:07 Segment locked: addr=700000010000000, size=268435456
> > 20:07:08 VP pid=2032150 priority fixed at 60
> >
> > Thu Apr 5 20:07:08 2012
> >
> > 20:07:08 Event alarms enabled. ALARMPROG =
> > '/opt/informix/INST1/scripts/alarmprogram.sh'
> > 20:07:08 Dynamically allocated new virtual shared memory segment (size
> > 1048576KB)
> > 20:07:08 Memory sizes:resident:262144 KB, virtual:1058816 KB, no SHMTOTAL
> > limit
> > 20:07:08 Booting Language<c> from module<>
> > 20:07:08 Loading Module<CNULL>
> > 20:07:08 Booting Language<builtin> from module<>
> > 20:07:08 Loading Module<BUILTINNULL>
> > 20:07:14 DR: DRAUTO is 0 (Off)
> > 20:07:14 DR: ENCRYPT_HDR is 0 (HDR encryption Disabled)
> > 20:07:14 AIX MP latch code enabled
> > 20:07:14 Requested shared memory segment size rounded from 548KB to 560KB
> > 20:07:14 Dynamically allocated new message shared memory segment (size
> 560KB)
> > 20:07:14 Memory sizes:resident:262144 KB, virtual:1059376 KB, no SHMTOTAL
> > limit
> > 20:07:14 Requested shared memory segment size rounded from 548KB to 560KB
> > 20:07:14 Dynamically allocated new message shared memory segment (size
> 560KB)
> > 20:07:14 Memory sizes:resident:262144 KB, virtual:1059936 KB, no SHMTOTAL
> > limit
> > 20:07:14 Fast poll pollset enabled.
> > 20:07:14 IBM Informix Dynamic Server Version 11.70.FC4 Software Serial
> Number
> > AAA#B000000
> > 20:07:15 IBM Informix Dynamic Server Initialized -- Shared Memory
> Initialized.
> >
> > ... but it doesn't:
> >
> > svmon -G
> >
> > size inuse free pin virtual mmode
> > memory 31522816 22513142 9009674 22097181 2011105 Ded
> > pg space 131072 4806
> >
> > work pers clnt other
> > pin 699341 0 0 934224
> > in use 2011105 0 38421
> >
> > PageSize PoolSize inuse pgsp pin virtual
> > s 4 KB - 1367030 4806 1260061 1328609
> > m 64 KB - 42656 0 23344 42656
> > L 16 MB 4996 0 0 4996 0
> >
> > Any ideas please? probably something really stupid and obvious.
> >
> > Thanks
> > Neil
> >
> >
> >
>
>
*******************************************************************************
> > Forum Note: Use "Reply" to post a response in the discussion forum.
> >
>
>
>
>
*******************************************************************************
> Forum Note: Use "Reply" to post a response in the discussion forum.
>
>
--
Eric B. Rowell
--047d7b33d928d9cde304bcf60be7