I have the below code,
IJsEngineSwitcher engineSwitcher = JsEngineSwitcher.Current;
engineSwitcher.EngineFactories.AddV8();
engineSwitcher.DefaultEngineName = V8JsEngine.EngineName;
_jsEngine = JsEngineSwitcher.Current.CreateDefaultEngine();
I want to monitor the memory used by the V8 engine on the server-side. Is there any way I can log this information?
Related
ZwQueryVirtualMemory reports on virtual memory in the address space of a process. I would like to do the same thing, but for paged memory in system space. Is there an equivalent function that deals with system space instead of process space?
You could use ZwQuerySystemInformation with SystemModuleInformation to get all running drivers. Then you can find the entry you want and get the base and size of the driver. You could if you want to do it properly only get the base of a driver with using the same method of above or using the PsLoadedModuleList to get the base of the targeted driver and then just walk the sections manually with the headers.
Also a tip, if you are going to copy it to dump it, use MmCopyMemory.
i have an App running in windows，and i create an shared_memory (with boost/interprocess) to act as a cache to supply some infos to the app. when i use the shared_memory, i had to insure the shard_memory is alive， indetail that i have to ensure i can get right date from shard_data in below.
shmObjWin = new windows_shared_memory(create_only, trueFileName, read_write, max_memory);
shmRegion = new mapped_region(*(context->shmObjWin), read_write);
shared_data = new(context->shmRegion->get_address()) shared_data_t;
My question is "how to ensure windows shared memory is alive?"
Thanks a lot.
Is it possible using ETW to also get memory statistics of all the processes and the system ?
With memory statistics I mean : e.g. Commited bytes, private bytes,paged pool,working set,...
I cannot find anything about using xperf to get and see memory statistics. It is always about CPU , disk , network.
One could probably use performance counters to get that kind of information, but how can one overlay the statistics graphically in one chart (how to correlate/sync the timestamps) ?
Your best bet on Windows 8.1 and higher is the Microsoft-Windows-Kernel-Memory provider, which records per-process memory information every 0.5 s. See https://github.com/google/UIforETW/issues/80 for details. UIforETW enables this by default when it is available.
You could also try the MEMINFO provider. It gives a system-wide overview of memory pressure. It shows the Active List (currently in use memory), the Standby List ('useful' pages not currently in use, such as the disk cache), and the Zero and Free lists (genuinely free memory). This at least lets you tell whether a system is running out of memory.
You could also try MEMINFO_WS and CONTMEMGEN but these are undocumented so I really don't know what they do. They show up in xperf -providers k but when I record with them I can't see any new graphs appearing. Apparently Microsoft ships these providers but no way to view them. Sigh...
If you want more memory details on Windows 7 -- such as per-process working sets -- your best bet is to have a process running which periodically queries this data and emits it in custom ETW events. This is available in a prepackaged form in UIforETW which can query the working set of a specified set of processes once a second. See the announcement post for how to get UIforETW:
https://randomascii.wordpress.com/2015/04/14/uiforetw-windows-performance-made-easier/
UIforETW's Windows 7 working set data shows up in Generic Events under Task Name == WorkingSet. On Windows 8.1 the OS working set data (more detailed, more efficiently recorded) shows up under Memory-> Virtual Memory Snapshots.
You can trace memory usage with ReferenceSet kernel group. It includes the following traceflags:
PROC_THREAD+LOADER+HARD_FAULTS+MEMORY+FOOTPRINT+VIRT_ALLOC+MEMINFO+VAMAP+SESSION+REFSET+MEMINFO_WS
MEMORY = Memory tracing
FOOTPRINT+REFSET = Support footprint analysis
MEMINFO = Memory List Info (active, standby and oters you see from ResMon)
VIRT_ALLOC = Virtual allocation reserve and release
VAMAP = mapped files information
MEMINFO_WS = Working set Info
As you can see xperf can capture a lot of memory data when you sue the right flags.
I'm hosting IronPython in a c#-based WebService to be able to provide custom extension scripts. However, I'm finding that memory usage sharply increases when I do simple load testing by executing the webservice repeatedly in a loop.
IronPython-1.1 implemented IDisposable on its objects so that you can dispose of them when they are done. The new IronPython-2 engine based on the DLR has no such concept.
From what I understood, everytime you execute a script in the ScriptEngine a new assembly is injected in the appdomain and can't be unloaded.
Is there any way around this?
You could try creating a new AppDomain every time you run one of your IronPython scripts. Although assebmlies cannot be unloaded from memory you can unload an AppDomain and this will allow you to get the injected assembly out of memory.
You need to disable the optimized code generation:
var runtime = Python.CreateRuntime();
var engine = runtime.GetEngine("py");
PythonCompilerOptions pco = (PythonCompilerOptions)engine.GetCompilerOptions();
pco.Module &= ~ModuleOptions.Optimized;
// this shouldn't leak now
while(true) {
var code = engine.CreateScriptSourceFromString("1.0+2.0").Compile(pco);
code.Execute();
}
Turns out, after aspnet_wp goes to about 500mb, the garbage collector kicks in and cleans out the mess. The memory usage then drops to about 20mb and steadily starts increasing again during load testing.
So there's no memory 'leak' as such.
I'm writing the memory manager for an application, as part of a team of twenty-odd coders. We're running out of memory quota and we need to be able to see what's going on, since we only appear to be using about 700Mb. I need to be able to report where it's all going - fragmentation etc. Any ideas?
You can use existing memory debugging tools for this, I found Memory Validator 1 quite useful, it is able to track both API level (heap, new...) and OS level (Virtual Memory) allocations and show virtual memory maps.
The other option which I also found very usefull is to be able to dump a map of the whole virtual space based on VirtualQuery function. My code for this looks like this:
void PrintVMMap()
{
size_t start = 0;
// TODO: make portable - not compatible with /3GB, 64b OS or 64b app
size_t end = 1U<<31; // map 32b user space only - kernel space not accessible
SYSTEM_INFO si;
GetSystemInfo(&si);
size_t pageSize = si.dwPageSize;
size_t longestFreeApp = 0;
int index=0;
for (size_t addr = start; addr<end; )
{
MEMORY_BASIC_INFORMATION buffer;
SIZE_T retSize = VirtualQuery((void *)addr,&buffer,sizeof(buffer));
if (retSize==sizeof(buffer) && buffer.RegionSize>0)
{
// dump information about this region
printf(.... some buffer information here ....);
// track longest feee region - usefull fragmentation indicator
if (buffer.State&MEM_FREE)
{
if (buffer.RegionSize>longestFreeApp) longestFreeApp = buffer.RegionSize;
}
addr += buffer.RegionSize;
index+= buffer.RegionSize/pageSize;
}
else
{
// always proceed
addr += pageSize;
index++;
}
}
printf("Longest free VM region: %d",longestFreeApp);
}
You can also find out information about the heaps in a process with Heap32ListFirst/Heap32ListNext, and about loaded modules with Module32First/Module32Next, from the Tool Help API.
'Tool Help' originated on Windows 9x. The original process information API on Windows NT was PSAPI, which offers functions which partially (but not completely) overlap with Tool Help.
Our (huge) application (a Win32 game) started throwing "Not enough quota" exceptions recently, and I was charged with finding out where all the memory was going. It is not a trivial job - this question and this one were my first attempts at finding out. Heap behaviour is unexpected, and accurately tracking how much quota you've used and how much is available has so far proved impossible. In fact, it's not particularly useful information anyway - "quota" and "somewhere to put things" are subtly and annoyingly different concepts. The accepted answer is as good as it gets, although enumerating heaps and modules is also handy. I used DebugDiag from MS to view the true horror of the situation, and understand how hard it is to actually thoroughly track everything.