Large amount of scsi-sgpool objects

Jan Engelhardt
2009-03-03T01:28:54Z

Hi,

I am noticing that there are a lot of objects active after a few tens
minutes of running xfs_fsr.

$ slabtop
OBJS ACTIVE USE OBJ SIZE SLABS OBJ/SLAB CACHE SIZE NAME
818616 818616 100% 0.16K 34109 24 136436K sgpool-8
253692 253692 100% 0.62K 42282 6 169128K sgpool-32
52017 52016 99% 2.50K 17339 3 138712K sgpool-128
26220 26219 99% 0.31K 2185 12 8740K sgpool-16
8927 8574 96% 0.03K 79 113 316K size-32

$ uname -a
Linux yaguchi 2.6.29-rc6-rt #1 SMP PREEMPT RT 2009-02-19 23:12:33
+0100 i686 athlon i386 GNU/Linux

What could be the problem that there are so many objects around and not
freed? This makes the system pretty much unusable after a while as it
runs towards a low-memory condition.

$ free
total used free shared buffers cached
Mem: 766592 758688 7904 0 0 137184
-/+ buffers/cache: 621504 145088
Swap: 795136 32 795104

$ cat /proc/meminfo
MemTotal: 766592 kB
MemFree: 79388 kB
Buffers: 0 kB
Cached: 62120 kB
SwapCached: 1428 kB
Active: 74472 kB
Inactive: 113524 kB
Active(anon): 58228 kB
Inactive(anon): 69124 kB
Active(file): 16244 kB
Inactive(file): 44400 kB
Unevictable: 0 kB
Mlocked: 0 kB
HighTotal: 0 kB
HighFree: 0 kB
LowTotal: 766592 kB
LowFree: 79388 kB
SwapTotal: 795136 kB
SwapFree: 792404 kB
Dirty: 0 kB
Writeback: 0 kB
AnonPages: 124440 kB
Mapped: 13672 kB
Slab: 478576 kB
SReclaimable: 5316 kB
SUnreclaim: 473260 kB
PageTables: 1220 kB
NFS_Unstable: 0 kB
Bounce: 0 kB
WritebackTmp: 0 kB
CommitLimit: 1178432 kB
Committed_AS: 4294655912 kB
VmallocTotal: 245816 kB
VmallocUsed: 27404 kB
VmallocChunk: 197108 kB
HugePages_Total: 0
HugePages_Free: 0
HugePages_Rsvd: 0
HugePages_Surp: 0
Hugepagesize: 4096 kB
DirectMap4k: 696256 kB
DirectMap4M: 90112 kB