privileged agent and malloc trim

[bungle]

privileged agent and malloc trim

[chobits]

@zhuizhuhaomeng thanks, I believe that nothing except init_worker handler is called on privileged agent, so it still feels about right that some malloc trim needs to be added for privileged agent too.

I’ll investigate it a bit more.

Perhaps we can set up a timer to actively call malloc_trim(1) using ffi in the privileged agent. This can help us see if the memory issue is due to free memory not being released.

[oowl]

I think privileged workers can not trigger lua_malloc_trim function， even if we have the openresty timer task (fake request), it still can not be trigger. So as @chobits said, we can call malloc_trim in luajit ffi function to do this.

[zhuizhuhaomeng]

@bungle OpenResty XRay can help you to identify the memory issue.
You can apply for a free trial https://xray.openresty.com.

[zhuizhuhaomeng]

As long as ngx_http_lua_log_handler is called, the malloc_trim will take effect.

[zhuizhuhaomeng]

As long as ngx_http_lua_log_handler is called, the malloc_trim will take effect.

[zhuizhuhaomeng]

You can use gdb and add breakpoint on malloc_trim to see if it happends.

[bungle]

@zhuizhuhaomeng thanks, I believe that nothing except init_worker handler is called on privileged agent, so it still feels about right that some malloc trim needs to be added for privileged agent too.

I’ll investigate it a bit more.

[bungle]

Reporting back here. We added FFI calls and tested it on Linux, but didn't find malloc_trim helping the situation. We need to do further investigation on memory usage before we can conclude anything. Thus I am closing this. Thank you!