Pushing the Limits of Windows: Paged and Nonpaged Pool

re: Pushing the Limits of Windows: Paged and Nonpaged Pool

Alex Silva — Mon, 08 Oct 2012 15:12:47 GMT

excellent.

re: Pushing the Limits of Windows: Paged and Nonpaged Pool

Hakan — Wed, 30 Mar 2011 19:05:36 GMT

I forgot to mention that I am using Windows 7.

re: Pushing the Limits of Windows: Paged and Nonpaged Pool

Hakan — Wed, 30 Mar 2011 18:55:26 GMT

Helpful article, thanks.

Also I would like to solicit opinion for the problem that I am debugging.

My software uses a Jungo driver for which I do not have a source code. At some point when I try to allocate memory it returns insufficient resource error.

I used a logger utility that came with the Jungo and extracted information that AllocateCommonBuffer fails which tells me that I am running out some memory resource somewhere. But I have plenty of physical memory ( 3 gb) which is available to me ( no special hardware hogging my memory making it unavailable to the system) . Since I am aware that kernel NonPaged pool is limited resource( 128 M on my system according to NonPagedPoolSize key in registery ) I have decided to use poolmon to see how I am running out of NonPaged memory and who is the culprit also this would tell me the Tag for the Jungo driver since I know the amount of memory I am allocating (8 Mb). Here is the strange part. According to the Poolmon no one is allocating 8Mb memory and there is plenty of Paged and NonPaged memory at the time AllocateCommonBuffer fails.

Now, I can hypothesize all kind of scenarios as to why the allocation fails. For example, maybe it needs something like NonPaged + Contiguous therefore it runs out of this flavor of memory or something. But I am not convinced by this kind of arguments since I do not have any way of verification of my hypothesis. I think the question I would like to ask is this : When I allocate 8Mb memory successfully with AllocateCommonBuffer where does the memory come from since I do not see anywhere Paged or NonPaged resources being reduced by this amount? Only indication of the allocation successful return of AllocateCommonBuffer and System PTE increased 2048 entries.

For those of you who have suggestions. I thank you for your time and attention.

re: Pushing the Limits of Windows: Paged and Nonpaged Pool

Trana — Thu, 21 Oct 2010 05:03:18 GMT

Great stuff, thanks.

I used to say an IT admin/support persons job is 50% Internet search, 50% compare settings side by side. But I am changing it to 33% Search, 33% Settings comparing and 34% Using tools created by Mark R.

Poolmon, Autoruns, Pagedefrag, ProcessExplorer, Disk2VHD, you name it...I love it!

re: Pushing the Limits of Windows: Paged and Nonpaged Pool

DaveH — Thu, 06 May 2010 18:45:04 GMT

Hi Mark,

First, great post. I've used this information to try and trace what was using all the non-paged memory on my server 2003 system - it's an old system and still running SP0 so there could be many bugfixes which would explain my problem.

I was getting volsnap events stating that it couldn't allocate enough nonpaged memory to hold a bitmap for a snapshot of my C: drive.

volsnap uses 16KB blocks in it's bitmap, so on my 69GB drive, I calculated 552KB for the bitmap.

It took me a while to get the symbols for the system so that I could see the nonpage pool limit.

The system in question was using 100 MB of nonpaged pool memory. Procexp.exe gave a limit of 256 MB of nonpaged pool memory. More than enough free for the bitmap.

I was confused! I removed the shadowstorage for the C: drive from it's second volume D: so that it would just use the C: drive and the problem went away!

Do you think this is a bug in the SP0 VSS implementation or do you really think I was running out of nonpaged memory?

Thanks,

Dave.

re: Pushing the Limits of Windows: Paged and Nonpaged Pool

nc — Fri, 16 Apr 2010 03:20:23 GMT

@miguel q

You need to configure symbols in Process Explorer so it can access the symbols for the kernel image.

re: Pushing the Limits of Windows: Paged and Nonpaged Pool

miguel q — Thu, 15 Apr 2010 21:40:27 GMT

Looking at the Process Explorer in Windows Server 2003 guest in VMware. I am able to see the Paged Physical and Virtual values but the Paged Limit reads "no symbols" What gives?

re: Pushing the Limits of Windows: Paged and Nonpaged Pool

Paul Hickman — Mon, 22 Mar 2010 20:14:58 GMT

Hi Mark,

There seems to be one kind of memory allocation that I haven't seen covered by your articles. How do virtualisation products such as Sun Virtual Box allocate their memory? It doesn't show up in any of the process-level memory counters in task manager / process explorer / perfmon. The only place it seems to be counted is in the overall "Cached" memory on the performance tab of task manager and the equivilent in other tools.

re: Pushing the Limits of Windows: Paged and Nonpaged Pool

Ronald M — Thu, 28 Jan 2010 16:57:31 GMT

I have been trying to find the reason for a non paged pool leak on a windows server 2003 for quite some time now without much success. This happens randomly sometimes twice in a day. Here is the output from poolman when the non paged pool consumption was high. Is it possible to find from this output, the possible cause of the leak.

Memory:16771724K Avail:15716652K PageFlts: 76038 InRam Krnl: 2268K P:114036

Commit: 765728K Limit:33273512K Peak: 968688K Pool N:196572K P:1150

System pool information

Tag Type Allocs Frees Diff Bytes Per Alloc

Irp Nonp 15114034 (3654) 14980131 (3578) 133903 62270528 ( 33776) 465

usbp Nonp 292346 ( 136) 159911 ( 136) 132435 41995160 ( 0) 317

Mdl Nonp 578590 ( 286) 307149 ( 293) 271441 34807680 ( 80) 128

HidU Nonp 291648 ( 136) 159541 ( 136) 132107 13738616 ( 0) 103

MmCm Nonp 2463 ( 0) 2305 ( 0) 158 8316176 ( 0) 52634

MFE0 Nonp 210464239 (3115) 210434889 (3080) 29350 7450848 ( 3568) 253

HidC Nonp 264459 ( 0) 132319 ( 0) 132140 3175736 ( 0) 24

LSwi Nonp 1 ( 0) 0 ( 0) 1 2576384 ( 0) 2576384

Io Nonp 95706488 (65071) 95574219 (65071) 132269 2191368 ( 0) 1

HdCl Nonp 264402 ( 0) 132303 ( 0) 132099 2116896 ( 0) 16

TPLA Nonp 512 ( 0) 0 ( 0) 512 2097152 ( 0) 4096

TCPt Nonp 37255 ( 6) 37218 ( 6) 37 1664536 ( 0) 44987

File Nonp 13742294 ( 368) 13734330 ( 358) 7964 1213584 ( 1536) 152

VxSb Nonp 6 ( 0) 4 ( 0) 2 1171456 ( 0) 585728

Mm Nonp 1037 ( 0) 1025 ( 0) 12 1127512 ( 0) 93959

brcm Nonp 30 ( 0) 0 ( 0) 30 819184 ( 0) 27306

TCht Nonp 7652 ( 0) 7456 ( 58) 196 802816 (-237568) 4096

bRcm Nonp 8 ( 0) 0 ( 0) 8 685840 ( 0) 85730

naFF Nonp 299 ( 0) 1 ( 0) 298 656504 ( 0) 2203

Thre Nonp 155086 ( 7) 154036 ( 11) 1050 655200 ( -2496) 624

Pool Nonp 6 ( 0) 3 ( 0) 3 610304 ( 0) 203434

AfdC Nonp 149183 ( 30) 146111 ( 28) 3072 491520 ( 320) 160

LSwr Nonp 128 ( 0) 0 ( 0) 128 416768 ( 0) 3256

Even Nonp 3895544 ( 354) 3889534 ( 350) 6010 291088 ( 192) 48

Devi Nonp 705 ( 0) 350 ( 0) 355 270104 ( 0) 760

NDpp Nonp 95 ( 0) 14 ( 0) 81 267520 ( 0) 3302

TCPC Nonp 11370 ( 6) 8215 ( 0) 3155 265952 ( 480) 84

Vad Nonp 2730397 ( 9) 2725265 ( 9) 5132 246336 ( 0) 48

Hal Nonp 194560 ( 341) 194536 ( 340) 24 199968 ( 368) 8332

Ntf0 Nonp 3 ( 0) 0 ( 0) 3 196608 ( 0) 65536

Ntfr Nonp 20653 ( 0) 17959 ( 0) 2694 173384 ( 0) 64

AfdE Nonp 148107 ( 30) 147506 ( 28) 601 168280 ( 560) 280

TCPc Nonp 243685 ( 53) 240390 ( 49) 3295 158160 ( 192) 48

Sema Nonp 6766238 (2360) 6763555 (2360) 2683 150648 ( 0) 56

MmCi Nonp 27458 ( 0) 26860 ( 0) 598 141344 ( 0) 236

Dump Nonp 9 ( 0) 1 ( 0) 8 135600 ( 0) 16950

RceT Nonp 1 ( 0) 0 ( 0) 1 131072 ( 0) 131072

Muta Nonp 999419 ( 189) 997544 ( 189) 1875 125856 ( 0) 67

CcSc Nonp 255342 ( 10) 254961 ( 9) 381 121920 ( 320) 320

MmCa Nonp 1262482 ( 11) 1261431 ( 10) 1051 107792 ( 112) 102

VadS Nonp 1697218 (1113) 1694239 (1117) 2979 95328 ( -128) 32

Vadl Nonp 2237198 ( 116) 2235790 ( 118) 1408 90112 ( -128) 64

NtFs Nonp 874028 ( 18) 872463 ( 5) 1565 72712 ( 520) 46

Ntfi Nonp 115369 ( 12) 115125 ( 0) 244 66368 ( 3264) 272

Lfsr Nonp 6 ( 0) 2 ( 0) 4 65536 ( 0) 16384

PooL Nonp 8 ( 0) 0 ( 0) 8 65536 ( 0) 8192

AmlH Nonp 1 ( 0) 0 ( 0) 1 65536 ( 0) 65536

re: Pushing the Limits of Windows: Paged and Nonpaged Pool

Lanruzehh — Mon, 18 Jan 2010 10:55:44 GMT

Hi,

Very nice article Mark.

I have a couple of questions,

1. Is it poosible to increase the Non Paged pool memory limit beyond 75% of RAM on Windows Server 2008 ?

2. If the answer to question 1 is yes, how can you do that ?

Thanks,

Lanruzehh