问题
What does large VM page size and normal Memory usage numbers from Task Manager mean for an application? Do they mean the application is poorly performing in terms of memory usage?
We have an application which some users claim that make their XP machines slow.
We see that the user have other heavy applications running as well. But when we see their task Manager figures we realize "Memory Usage" column in task Mgr is normal for our app but the VM size is pretty high compared to others (including heavy applications).
E.g
Application X (Heavy size application & moderately slow) - Actual Usage (500 MB) - VM Usage (600 MB)
Our Application (Normal size application & very slow) - Actual usage (200 MB) - VM Size (900 MB) <==== Is this indication of our application leaking?
Can someone shed more light for me on this?
Thx
回答1:
Well, it is a piggy. A leak is possible, but only start checking for that when the VM size keeps climbing uncontrollably. The working set can certainly be much lower than the VM size, memory pages that don't get used will get swapped out to give other processes the RAM they need. A good statistic is Page Fault Delta, you'll have to add it. If that spikes a lot then a user complaint that the program slows down everything is likely to be valid.
There's one case that's not that uncommon in .NET, you'll consume a lot of VM but little working set when you have a large number of embedded resources. Which is okay.
Using a memory profiler is of course highly indicated, gives you much more insight than Task Manager.
来源：https://stackoverflow.com/questions/19951087/xp-large-virtual-memory-normal-mem-usage-in-task-manager