Strange memory behavior

I have a strange memory behavior in an Android application I'm developing. The application is running fine, but if I look to a "task manager" in Android, like the Samsung SII task manager or the "Memory Usage" application on a Nexus 7 it shows that while using the app the amount of memory used is rapidly growing to an insane amount, like hundreds of megas (600~700MB on the Nexus 7).

I run a CentOS 5.7 64 machine with 24gb ram and running kernel 2.6.18-274.12.1.el5.

This machine runs only Nginx, php-fpm and Xcache as extra applications.

Since about 3 weeks my memory behavior on this machine has changed and I cannot explain why. There are no crons running which flush anything like this.

My application randomly returned OOM errors trying to allocate 16M chunks, while Linux had plenty memory used by disk cache (20G).

Swapping disabled. All OS limits seem fine.

After clearing Linux cache with drop_caches error disappeared.

Any idea what to check or is it somehow expected behavior?

Here's what the memory graph looks like on a VPS running CentOS with 512MB of RAM and nginx/php-fpm/mysqld serving (mostly static) content to a couple thousand visitors per day.

As you can see, it's quite jumpy in the cache and buffer area. The memory cache is purged at irregular intervals (ruling out a responsible cron job).

Every process has the possibility to address 2^32 or 2^64 bits of virtual memory. The moment you request to read or to write to one of these memory address', it is converted to a physical memory location (based on the process ID) as it is sent to your L1 data cache.

Hi Experts,

Our servers running Solaris 10 with SAP Application. The memory utilization always >90%, but the process on SAP is too less even nothing.

Why memory utilization on solaris always looks high?

I have statement about memory on solaris, is this true: Memory in solaris is used for I/O cache, so if there is no memory in used, memory will be used by I/O cache.

I have the following questions regarding Linux memory:

I know that the active memory is the portion of memory which is most frequently accessed. But can someone explain me how linux considers a memory location to be utilised for active memory or inactive memory. What all components does active memory comprises of ?

Embedded system, no swap, kernel v2.6.36, memory compaction enabled.

Under heavy usage, all the RAM is tied up in cache. Cache was using about 70M of memory. When a user space process allocates memory, no problem, cache gives it up.

But there's a 3rd party device driver that seems to try to allocate a physical 5th order page, and fails with OOM. A quick look at buddyinfo confirms this...

I'm running Windows 7 SP1 on a MacBook Pro via Boot Camp (i.e. it boots natively).

Recently services.exe started exhibiting behavior whereby every 15 minutes or so it will ramp up over the course of 1-2 minutes to use all available memory on the system (in my case all 8GB of memory).