big memory overhead with p-ave and multiple processes inside   

Hi BR,

Unfortunately, there is a memory usage overhead inherent in Lx86, due to the extra code translations it needs to maintain. The soon-to-be-released PowerVM Lx86 1.3.1 should incur less overhead than the earlier versions, so you may wish to try this version when it is available and see if it improves your application. If you still see much higher than expected memory use, please let us know and we may be able to investigate further to see if memory usage can be reduced in your environment.

Hello,
MEMORY_MONITOR_TRIGGER_RATIO=x is the correct configuration option too limit the amount of memory used a process.

This option needs to be placed in powervm-lx86's config file (/etc/opt/powervm-lx86/config), you may have to create this file if it doesn't exist. Next powervm-lx86 will require a restart.

1. /etc/init.d/powervm-lx86 start

I am guessing that when you said that it made no difference to the memory usage you hadn't restarted powervm-lx86?

Regards,
Karl

Thanks for you reply,

I did restart the powervm-lx86 (but by using the "service" command. Inform me if this the wrong procedure).

Here are the results
<MEMORY_MONITOR_TRIGGER_RATIO=250>

1. more /etc/opt/powervm-lx86/config

MEMORY_MONITOR_TRIGGER_RATIO=250

1. service powervm-lx86 restart
2. top n 1 b | grep powervm

365 root 16 0 90240 16m 5056 S 0.0 1.6 0:00.05 powervm-lx86
373 root 21 0 88768 15m 5056 S 0.0 1.5 0:00.02 powervm-lx86
398 root 21 0 95552 17m 5312 S 0.0 1.8 0:00.15 powervm-lx86
32762 daemon 15 0 172m 4928 2560 S 0.0 0.5 0:00.01 powervm-lx86-da

＜MEMORY_MONITOR_TRIGGER_RATIO=100＞

1. more /etc/opt/powervm-lx86/config

MEMORY_MONITOR_TRIGGER_RATIO=100

1. service powervm-lx86 restart
2. top n 1 b | grep powervm

611 daemon 15 0 108m 4864 2560 S 0.0 0.5 0:00.02 powervm-lx86-da
672 root 15 0 90240 16m 5056 S 0.0 1.6 0:00.05 powervm-lx86
680 root 20 0 88768 15m 5120 S 0.0 1.5 0:00.02 powervm-lx86
704 root 18 0 95552 17m 5312 S 0.0 1.8 0:00.14 powervm-lx86

From the results, It seems that the memory usage of powervm-lx86-daemon has decreased. However sometimes the amount of virtual memory is the same even when MEMORY_MONITOR_TRIGGER_RATIO is set to 250 or 100.

Here is another result

<Another result when MEMORY_MONITOR_TRIGGER_RATIO=250>

1. more /etc/opt/powervm-lx86/config

MEMORY_MONITOR_TRIGGER_RATIO=250

1. service powervm-lx86 restart
2. top n 1 b | grep powervm

7970 daemon 15 0 108m 4864 2560 S 0.0 0.5 0:00.01 powervm-lx86-da
8032 root 16 0 90240 16m 5056 S 0.0 1.6 0:00.05 powervm-lx86
8040 root 18 0 88768 15m 5120 S 0.0 1.5 0:00.02 powervm-lx86
8064 root 21 0 95552 17m 5312 S 0.0 1.8 0:00.14 powervm-lx86

So I am uncertain if MEMORY_MONITOR_TRIGGER_RATIO has an effect for decreasing the memory usage. ( I apologize for saying "no difference" in the previous comment")

Also can you help me with the manual?
In the manual it has:

"The amount of virtual memory used by PowerVM Lx86 can be restricted, specified as a ratio to the amount of memory used by the x86 application being translated. When PowerVM Lx86's memory use exceeds this ratio, it will discard Power code translations until it is within the allowed threshold.

The limit is set to 250% of the x86 application's memory usage by default; that is PowerVM Lx86 will not use more than two and a half times the amount of memory that the x86 application would have used. Setting the value to 100% will cap the memory usage when it reaches 1:1 with the x86 application usage. Setting the ratio to zero will disable the limit. Setting the limit to a low ratio, less than the default, may impact the performance of PowerVM Lx86 and hence the x86 application being translated."

what does "x86 application's" mean in above? Does this mean the "powervm-lx86" process that can be seen in the ps (or top) command?

Thanks,