r7vme's profile - activity

thanks, helped me as well!

Created github issue https://github.com/ros2/realtime_support/issues/87

Hello, i'm going thru rttest ulitity and was wondering why "lock_and_prefault_dynamic()" always locks 8GB of heap memory?

Steps to reproduce: 1. Build as described in README.md 2. Set unlimited memlock user - memlock -1 in /etc/security/limits.conf, relogin 3. Run ./example_loop -i 10000 4. In separate terminal check memory usage by top (RES column)

8GB also mentioned in Real-Time-Programming

From what i understand lock_and_prefault_dynamic() sets allocation options (no trim, no mmap) and then allocates memory in 64*4k chunks until allocation hits NO page faults. The question is why it's always 8GB?

I'm testing on NVIDIA Jetson AGX Xavier which has 16GB ram.

EDIT:

also checked on google cloud VM with 32GB of total ram (no swap). Getting same number 8GB

My Xavier ulimit -a

core file size          (blocks, -c) 0
data seg size           (kbytes, -d) unlimited
scheduling priority             (-e) 0
file size               (blocks, -f) unlimited
pending signals                 (-i) 62481
max locked memory       (kbytes, -l) unlimited
max memory size         (kbytes, -m) unlimited
open files                      (-n) 1024
pipe size            (512 bytes, -p) 8
POSIX message queues     (bytes, -q) 819200
real-time priority              (-r) 0
stack size              (kbytes, -s) 81920
cpu time               (seconds, -t) unlimited
max user processes              (-u) 62481
virtual memory          (kbytes, -v) unlimited
file locks                      (-x) unlimited

Thanks to @sgermanserrano for pointing out to his workaround on how to decrease memory usage this gave me a first clue o

gotcha pointer size is 8 bytes (not 4), now all is clear

I think i've got the trick. std::vector copies data to new memory, when it resizes itself, so in the heap there are so

I think i've got the trick. std::vector is copied to new memory, when it allocates additional memory, so in the heap th

Ah, wait std::vector allocates memory on the heap. So as soon as big allocation happens (+32k * 4bytes size of pointer)

i like your workaround, but i believe reason in std::vector (as i just found out). I see that page faults are stopped as

What threads are running in minimal ROS2 publisher? Hello, i'm trying to find out what are those 7 threads that i see if

Why rttest allocates 8GB of memory? Hello, i'm going thru rttest ulitity and was wondering why "lock_and_prefault_dynami

Why rttest allocates 8GB of memory? Hello, i'm going thru rttest ulitity and was wondering why "lock_and_prefault_dynami

Why rttest allocates 8GB of memory? Hello, i'm going thru rttest ulitity and was wondering why "lock_and_prefault_dynami

Good to hear! @joonhyup can you please accept answer if it helped?

Issue is because tf2_ros was compiled for python2. Detailed discussion here. To recompile for python3 (melodic): Insta

Hey, take a look on https://github.com/tue-robotics/wire Paper: https://pure.tue.nl/ws/portalfiles/portal/3390005/2207

thanks! small correction: e.g. for milliseconds we also need to multiply by 1e6. int nsecs = (msg->angle_timestamp