kmeminfo questio related to dynamic memory

[W L Wong]

Hello,
Part of the kmeminfo output :
Dynamic = 345751 1.3g 13% Kernel dynamic memory
Arenas = 276091 1.1g 11% Kernel arenas
M_TEMP = 193445 755.6m 7%
M_SPINLOCK = 17973 70.2m 1%
M_SWAP = 10451 40.8m 0%
M_NFS_GEN = 8864 34.6m 0%
M_LVM = 8804 34.4m 0%
M_IOSYS = 6697 26.2m 0%
VFD_BT_NODE = 6495 25.4m 0%
ALLOCB_MBLK_LM = 4533 17.7m 0%
KMEM_ALLOC = 2367 9.2m 0%
M_DYNAMIC = 1423 5.6m 0%

What are the M* areas, eg M_TEMP ? And why is it using so much memory (700MB), and any way to reduce this amount ?

Thanks.

[Steve Steel]

Hi

Kernel dynamic memory usage (in page/byte/percent):

Dynamic = 100043 390.8m 5% Kernel dynamic memory
Arenas = 64553 252.2m 3% Kernel arenas
M_TEMP = 19504 76.2m 1%
M_SWAP = 12468 48.7m 1%
M_LVM = 4761 18.6m 0%
KMEM_ALLOC = 4647 18.2m 0%
ALLOCB_MBLK_LM = 4052 15.8m 0%
M_IOSYS = 3368 13.2m 0%
ALLOCB_MBLK_DA = 2941 11.5m 0%
M_SPINLOCK = 2416 9.4m 0%
VFD_BT_NODE = 1312 5.1m 0%
ALLOCB_MBLK_SM = 1296 5.1m 0%
M_DYNAMIC = 1067 4.2m 0%
KMEM_VARFLIST_H = 882 3.4m 0%
ALLOCB_MBLK_MH = 780 3.0m 0%
M_PREG = 597 2.3m 0%
M_REG = 590 2.3m 0%
Other = 3872 15.1m 0% Other arenas...
Kalloc = 35399 138.3m 2% kalloc()
SuperPagePool = 17584 68.7m 1% Kernel superpage cache
BufcacheBufs = 11235 43.9m 1% Buffer cache bufs
BufcacheHash = 5120 20.0m 0% Buffer cache hash heads
Other = 1460 5.7m 0% Other...
Eqalloc = 91 364.0k 0% eqalloc()



This can be tuning patches or applications .


See

ftp://eh:spear9@hprc.external.hp.com/memory.htm



Steve Steel

[Geoff Wild]

M areas are dynamic memory - your TEMP is using only 7%

This thread has some good info:

http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=68965

Rgds...Geoff

[Don Morris_1]

M* arenas are legacy arenas for kernel clients using the pre-Arena MALLOC/FREE interfaces (M == MALLOC).

As to why someone's using a bunch of M_TEMP, that's rather difficult to answer. Knowing what kernel your running (including patches) might help a bit -- but there's always the issue of 3rd part drivers, DLKMs, etc... M_TEMP is a kernel-wide resource, after all.

That memory may well be free, by the way (just awaiting garbage collection). What does

kmeminfo -arena "M_TEMP"

look like? Is your system under memory pressure?