memory

问题 I'm looking for a way for the application itself to monitor the amount of memory it is using, so I can record it in a log file every hour or so and keep an eye on the applications usage. Its all hosted so we can make changes to the system to see what is going on so the solution will have to be from within the application code. We may in future use the memory information to affect the caching policies. 回答1: Hmm, how detailed information do you need? If you just want the memory usage you can

问题 I'm using Linux, go, and os/exec to run some commands. I want to know a process' realtime memory usage. That means that I can ask for memory usage anytime after I start the process, not just after it ran. (That's why the answer in Measuring memory usage of executable run using golang is not an option for me) For example: cmd := exec.Command(...) cmd.Start() //... if cmd.Memory()>50 { fmt.Println("Oh my god, this process is hungry for memory!") } I don't need very precise value, but it would

问题 I recently came across this article about python memory allocation. In this page it describes the memory usage of python and in there there is an example showing deepcopy of list of integers. I did the benchmark myself on Python 2.7 Line # Mem usage Increment Line Contents ================================================ 4 28.051 MiB 0.000 MiB @profile 5 def function(): 6 59.098 MiB 31.047 MiB x = list(range(1000000)) # allocate a big list 7 107.273 MiB 48.176 MiB y = copy.deepcopy(x) 8 99

问题 In CPU world one can do it via memory map. Can similar things done for GPU? If two process can share a same CUDA context, I think it will be trivial - just pass GPU memory pointer around. Is it possible to share same CUDA context between two processes? Another possibility I could think of is to map device memory to a memory mapped host memory. Since it's memory mapped, it can be shared between two processes. Does this make sense / possible, and are there any overhead? 回答1: CUDA MPS

问题 At first glance it seems like a good idea to let the hard disk write to RAM on its own, without CPU instructions copying data, particularly with the success of asynchronous networking in mind. But the Wikipedia article on Direct Memory Access (DMA) states this: With DMA, the CPU gets freed from this overhead and can do useful tasks during data transfer (though the CPU bus would be partly blocked by DMA). I don't understand how a bus line can be "partly blocked". Presumably memory can be

问题 Let's say I declare a pointer of char, and call delete on it without having called new. Can this cause a problem? char* myptr; if (condition) //do something involving myptr = new char[SIZE]; else //do something that doesnt involve myptr //do more stuff delete[] myptr; I don't delete myptr under the if because another pointer in //do more stuff can point to it if condition was true. Obviously this works fine if condition was true because a "new" was called on myptr . Is deleting myptr bad if I

问题 How to get total memory in bytes used by OpenGL in C++? I'm building an OpenGL application and the total memory used seems to be rising, I can get the info about the total memory used by variables & objects created by myself but can't guarantee how much memory OpenGL is using for its variables & objects & textures, etc. So is it possible to get the total memory in bytes used by OpenGL in C++? 回答1: In general, you don't. OpenGL is ultimately a hardware abstraction. And OpenGL simply doesn't

问题 I have a created a temporary table using the memory engine as followed: CREATE TEMPORARY TABLE IF NOT EXISTS some_text ( id INT DEFAULT 0, string varchar(400) DEFAULT '' ) engine = memory; When I insert rows into it I run into a #1114 error because the table is full. It explains in the mysql docs that changing the tmp_table_size and the max_heap_table_size don't do anything for increasing the size of user created temp tables, which is what I think I have here. How do I go about making this

问题 The toString method of Object is unique in that it seems to be the only place in Java where the memory address is viewable. How does Object do this? I would like to know so that I can mimic its implementation in a class of my own. I can't use super.toString() because I'm extending a class which overrides toString already. Update: The premise of my question asks for the memory address, but the answers have indicated that this premise is incorrect, so what I am actually asking is: How does

问题 Of 192GB RAM installed on my computer, I have 188GB RAM above 4GB (at hardware address 0x100000000) reserved by the Linux kernel at boot time (mem=4G memmap=188G$4G). A data acquisition kernel modules accumulates data into this large area used as a ring buffer using DMA. A user space application mmap's this ring buffer into user space, then copies blocks from the ring buffer at the current location for processing once they are ready. Copying these 16MB blocks from the mmap'ed area using