memstat: memory status and large page blocks available

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MEMSTAT prints memory status and tries to allocate all available memory using the largest possible blocks. It does it twice: first, using 4kb pages and again with 2/4 mb pages. This program is mainly useful to check whether you can run some software requiring large contiguous memory blocks, like 32-bit 7-zip or 7-zip in largepage (-slp) mode

Program transcript, including several runs of 64-bit version. Note that set of 4mb-paged memory blocks differs from run to run, and that program is rather slow (about 20 secs on my box):

Code:

C:\>t memstat32.exe There is 17 percent of memory in use. There are 16360 total Mbytes of physical memory. There are 13447 free Mbytes of physical memory. There are 16374 total Mbytes of paging file. There are 12841 free Mbytes of paging file. There are 4095 total Mbytes of virtual memory. There are 4081 free Mbytes of virtual memory. There are 0 free Mbytes of extended memory. Memory allocation using VirtualAlloc with 4kb pages: Allocated 2047 mb, addr=7FFF0000 Allocated 1857 mb, addr=00790000 Allocated 122 mb, addr=774F0000 Allocated 13 mb, addr=75B40000 Allocated 4 mb, addr=74E10000 Allocated 3 mb, addr=76BB0000 Allocated 3 mb, addr=75660000 Allocated 2 mb, addr=74AB0000 Allocated 1 mb, addr=00590000 Allocated 1 mb, addr=753D0000 Allocated 1 mb, addr=77040000 Allocated 1 mb, addr=75A00000 Total: 4063 mb Memory allocation using VirtualAlloc with 2/4mb pages: Allocated 2044 mb, addr=80000000 Allocated 1852 mb, addr=00A00000 Allocated 120 mb, addr=77600000 Allocated 12 mb, addr=75C00000 Total: 4028 mb Elapsed time = 0.632 seconds C:\>t memstat64.exe There is 17 percent of memory in use. There are 16360 total Mbytes of physical memory. There are 13554 free Mbytes of physical memory. There are 16374 total Mbytes of paging file. There are 12932 free Mbytes of paging file. There are 8388607 total Mbytes of virtual memory. There are 8388597 free Mbytes of virtual memory. There are 0 free Mbytes of extended memory. Memory allocation using VirtualAlloc with 4kb pages: Allocated 16383 mb, addr=0000000080000000 Allocated 8191 mb, addr=0000000480000000 Allocated 4091 mb, addr=0000000680000000 Allocated 507 mb, addr=0000000000820000 Allocated 30 mb, addr=0000000020420000 Allocated 15 mb, addr=0000000022320000 Allocated 9 mb, addr=0000000023320000 Allocated 1 mb, addr=0000000000410000 Total: 29233 mb Memory allocation using VirtualAlloc with 2/4mb pages: Allocated 8424 mb, addr=0000000080000000 Allocated 2280 mb, addr=000000028E800000 Allocated 540 mb, addr=0000000000C00000 Allocated 152 mb, addr=0000000022800000 Total: 11396 mb Elapsed time = 17.393 seconds C:\>t memstat64.exe There is 17 percent of memory in use. There are 16360 total Mbytes of physical memory. There are 13543 free Mbytes of physical memory. There are 16374 total Mbytes of paging file. There are 12924 free Mbytes of paging file. There are 8388607 total Mbytes of virtual memory. There are 8388597 free Mbytes of virtual memory. There are 0 free Mbytes of extended memory. Memory allocation using VirtualAlloc with 4kb pages: Allocated 16383 mb, addr=0000000080000000 Allocated 8191 mb, addr=0000000480000000 Allocated 4091 mb, addr=0000000680000000 Allocated 507 mb, addr=0000000000650000 Allocated 30 mb, addr=0000000020250000 Allocated 14 mb, addr=0000000022150000 Total: 29221 mb Memory allocation using VirtualAlloc with 2/4mb pages: Allocated 8424 mb, addr=0000000080000000 Allocated 2280 mb, addr=000000028E800000 Allocated 484 mb, addr=0000000000A00000 Allocated 108 mb, addr=000000001EE00000 Allocated 24 mb, addr=0000000025A00000 Allocated 4 mb, addr=0000000027200000 Allocated 4 mb, addr=0000000027600000 Total: 11328 mb Elapsed time = 17.497 seconds C:\>t memstat64.exe There is 17 percent of memory in use. There are 16360 total Mbytes of physical memory. There are 13548 free Mbytes of physical memory. There are 16374 total Mbytes of paging file. There are 12948 free Mbytes of paging file. There are 8388607 total Mbytes of virtual memory. There are 8388597 free Mbytes of virtual memory. There are 0 free Mbytes of extended memory. Memory allocation using VirtualAlloc with 4kb pages: Allocated 16383 mb, addr=0000000080000000 Allocated 8191 mb, addr=0000000480000000 Allocated 4091 mb, addr=0000000680000000 Allocated 507 mb, addr=0000000000670000 Allocated 59 mb, addr=0000000020270000 Allocated 10 mb, addr=0000000023E70000 Total: 29246 mb Memory allocation using VirtualAlloc with 2/4mb pages: Allocated 9704 mb, addr=0000000080000000 Allocated 1000 mb, addr=0000000000A00000 Allocated 236 mb, addr=000000003F200000 Total: 10940 mb Elapsed time = 5.934 seconds C:\>t memstat64a.exe There is 17 percent of memory in use. There are 16360 total Mbytes of physical memory. There are 13521 free Mbytes of physical memory. There are 16374 total Mbytes of paging file. There are 12919 free Mbytes of paging file. There are 8388607 total Mbytes of virtual memory. There are 8388597 free Mbytes of virtual memory. There are 0 free Mbytes of extended memory. Memory allocation using VirtualAlloc with 4kb pages: Allocated 16383 mb, addr=0000000080000000 Allocated 8187 mb, addr=0000000480000000 Allocated 4603 mb, addr=000000067FC00000 Allocated 31 mb, addr=00000000006D0000 Allocated 8 mb, addr=00000000026D0000 Allocated 1 mb, addr=0000000002F00000 Allocated 1 mb, addr=0000000003080000 Total: 29218 mb Memory allocation using VirtualAlloc with 2/4mb pages: Allocated 6452 mb, addr=0000000080000000 Allocated 1964 mb, addr=0000000213400000 Allocated 532 mb, addr=0000000000A00000 Allocated 240 mb, addr=0000000021E00000 Allocated 24 mb, addr=0000000030E00000 Allocated 4 mb, addr=0000000032600000 Allocated 4 mb, addr=0000000032A00000 Total: 9220 mb Elapsed time = 420.470 seconds

I get this (2.0 GHz T3200, 3 GB, 32 bit Vista)

Code:

C:\tmp>memstat32 There is 50 percent of memory in use. There are 3000 total Mbytes of physical memory. There are 1489 free Mbytes of physical memory. There are 6222 total Mbytes of paging file. There are 4608 free Mbytes of paging file. There are 2047 total Mbytes of virtual memory. There are 2035 free Mbytes of virtual memory. There are 0 free Mbytes of extended memory. Memory allocation using VirtualAlloc with 4kb pages: Allocated 1874 mb, addr=009A0000 Allocated 128 mb, addr=77680000 Allocated 14 mb, addr=76660000 Allocated 7 mb, addr=7F7F0000 Allocated 7 mb, addr=75CE0000 Allocated 1 mb, addr=00240000 Allocated 1 mb, addr=00410000 Total: 2034 mb Memory allocation using VirtualAlloc with 2/4mb pages: Total: 0 mb... C:\tmp>memstat32 There is 50 percent of memory in use. There are 3000 total Mbytes of physical memory. There are 1488 free Mbytes of physical memory. There are 6222 total Mbytes of paging file. There are 4607 free Mbytes of paging file. There are 2047 total Mbytes of virtual memory. There are 2035 free Mbytes of virtual memory. There are 0 free Mbytes of extended memory. Memory allocation using VirtualAlloc with 4kb pages: Allocated 1875 mb, addr=00840000 Allocated 128 mb, addr=77680000 Allocated 14 mb, addr=76660000 Allocated 7 mb, addr=7F7F0000 Allocated 7 mb, addr=75CE0000 Total: 2033 mb Memory allocation using VirtualAlloc with 2/4mb pages: Total: 0 mb...

it's possible after long run of windows. memory space becomes fragmented and less large pages are available. if you can, try reboot the system and run the program