Swapping refers to copying the entire process address space, or at any rate, the non-shareable-text data segment, out to the swap device, or back, in one go (typically disk). Whereas paging refers to copying in/out one or more pages of the address space. In particular, this is at a much finer grain. For example, there … Read more
result = [list(someListOfElements) for _ in xrange(x)] This will make x distinct lists, each with a copy of someListOfElements list (each item in that list is by reference, but the list its in is a copy). If it makes more sense, consider using copy.deepcopy(someListOfElements) Generators and list comprehensions and things are considered quite pythonic.
You can use the unsafe.Sizeof function for this. It returns the size in bytes, occupied by the value you pass into it. Here’s a working example: package main import “fmt” import “unsafe” func main() { a := int(123) b := int64(123) c := “foo” d := struct { FieldA float32 FieldB string }{0, “bar”} fmt.Printf(“a: … Read more
There isn’t much overhead for malloc, so you are unlikely to achieve any run-time savings. There is, however, a good reason to implement an allocator on top of malloc, and that is to be able to trace memory leaks. For example, you can free all memory allocated by the program when it exits, and then … Read more
In the search of answer, I posted the same question on Quora and Robert Love answered it: I’m assuming you are asking this from the point-of-view of the user of a system, or perhaps someone building a kernel for a particular product. As a kernel developer, you don’t care what “slab” allocator is in use; … Read more
Relative to other managed languages like Java and C#, purely functional languages allocate like crazy. They also allocate objects of different sizes. The fastest known allocation strategy is to allocate from contiguous free space (sometimes called a “nursery”) and to reserve a hardware register to point to the next available free space. Allocation from the … Read more
Yes every process has its own pagetables. They might be shared with the parent process(copy on write) or with other processes(shared memory). But in general every process has its own.
The memory you need to assign to the driver depends on the job. If the job is based purely on transformations and terminates on some distributed output action like rdd.saveAsTextFile, rdd.saveToCassandra, … then the memory needs of the driver will be very low. Few 100’s of MB will do. The driver is also responsible of … Read more
In operating systems that implement a virtual memory space the programs allocate memory from an address space that may be much larger than the actual amount of RAM the system possesses. The OS is responsible for deciding which programs “memory” is in actual RAM. It needs a place to keep things while they are “out”. … Read more
On Mac, $IDEA_HOME/Contents/Info.plist ~: grep –context=5 Xmx /Applications/Maia-IU-94.426.app/Contents/Info.plist <string>true</string> <key>apple.awt.fullscreencapturealldisplays</key> <string>false</string> </dict> <key>VMOptions</key> <string>-Xms128m -Xmx912m -Dfile.encoding=UTF-8 -XX:MaxPermSize=250m -ea -agentlib:yjpagent=disablej2ee,disablecounts,disablealloc,sessionname=IntelliJIdea90 -Xbootclasspath/a:../lib/boot.jar</string> <key>WorkingDirectory</key> <string>$APP_PACKAGE/bin</string> </dict> </dict> </plist> On Windows/Linux, %IDEA_HOME%\bin\idea.vmoptions