EEheap sos
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!EEHeap [-gc] [-loader]
!EEHeap enumerates process memory consumed by internal CLR data structures. You
can limit the output by passing "-gc" or "-loader". All information will be
displayed otherwise.
The information for the Garbage Collector lists the ranges of each Segment in
the managed heap. This can be useful if you believe you have an object pointer.
If the pointer falls within a segment range given by "!EEHeap -gc", then you do
have an object pointer, and can attempt to run "!DumpObj" on it.
Here is output for a simple program:
0:000> !eeheap -gc
Number of GC Heaps: 1
generation 0 starts at 0x00a71018
generation 1 starts at 0x00a7100c
generation 2 starts at 0x00a71000
segment begin allocated size
00a70000 00a71000 00a7e01c 0000d01c(53276)
Large object heap starts at 0x01a71000
segment begin allocated size
01a70000 01a71000 01a76000 0x00005000(20480)
Total Size 0x1201c(73756)
------------------------------
GC Heap Size 0x1201c(73756)
So the total size of the GC Heap is only 72K. On a large web server, with
multiple processors, you can expect to see a GC Heap of 400MB or more. The
Garbage Collector attempts to collect and reclaim memory only when required to
by memory pressure for better performance. You can also see the notion of
"generations," wherein the youngest objects live in generation 0, and
long-lived objects eventually get "promoted" to generation 2.
The loader output lists various private heaps associated with AppDomains. It
also lists heaps associated with the JIT compiler, and heaps associated with
Modules. For example:
0:000> !EEHeap -loader
Loader Heap:
--------------------------------------
System Domain: 5e0662a0
LowFrequencyHeap:008f0000(00002000:00001000) Size: 0x00001000 bytes.
HighFrequencyHeap:008f2000(00008000:00001000) Size: 0x00001000 bytes.
StubHeap:008fa000(00002000:00001000) Size: 0x00001000 bytes.
Total size: 0x3000(12288)bytes
--------------------------------------
Shared Domain: 5e066970
LowFrequencyHeap:00920000(00002000:00001000) 03e30000(00010000:00003000) Size: 0x00004000 bytes.
Wasted: 0x00001000 bytes.
HighFrequencyHeap:00922000(00008000:00001000) Size: 0x00001000 bytes.
StubHeap:0092a000(00002000:00001000) Size: 0x00001000 bytes.
Total size: 0x6000(24576)bytes
--------------------------------------
Domain 1: 14f000
LowFrequencyHeap:00900000(00002000:00001000) 03ee0000(00010000:00003000) Size: 0x00004000 bytes.
Wasted: 0x00001000 bytes.
HighFrequencyHeap:00902000(00008000:00003000) Size: 0x00003000 bytes.
StubHeap:0090a000(00002000:00001000) Size: 0x00001000 bytes.
Total size: 0x8000(32768)bytes
--------------------------------------
Jit code heap:
Normal JIT:03ef0000(00010000:00002000) Size: 0x00002000 bytes.
Total size: 0x2000(8192)bytes
--------------------------------------
Module Thunk heaps:
Module 5ba22410: Size: 0x00000000 bytes.
Module 001c1320: Size: 0x00000000 bytes.
Module 001c03f0: Size: 0x00000000 bytes.
Module 001caa38: Size: 0x00000000 bytes.
Total size: 0x0(0)bytes
--------------------------------------
Module Lookup Table heaps:
Module 5ba22410:Size: 0x00000000 bytes.
Module 001c1320:Size: 0x00000000 bytes.
Module 001c03f0:Size: 0x00000000 bytes.
Module 001caa38:03ec0000(00010000:00002000) Size: 0x00002000 bytes.
Total size: 0x2000(8192)bytes
--------------------------------------
Total LoaderHeap size: 0x15000(86016)bytes
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By using !EEHeap to keep track of the growth of these private heaps, we are
able to rule out or include them as a source of a memory leak.
