Hi,
I suspect that there are some memory leaks in the SMP MIPS linux 2.4.9.
I would like to know if any one found the root cause and fixed them.
Here is the description of the memory leak that I am seeing-
1. Summary:
Memory leaks in Linux 2.4.9 MIPS SMP kernel
2. Description:
I see that MemFree, as reported by /proc/meminfo, goes down when
I run the following script.
while true
do
date
cat /proc/meminfo
cat /proc/slabinfo
done
MemFree goes down continuously when this script is run.
When I ran this script for 3-4 days, the MemFree went down
to 10% of MemTotal!
I just ran the script for 3 hours are here is the diff between
the out put of /proc/meminfo and /proc/slabinfo before and
after the test run ( lines with "<" are before the test and
lines with ">" are after the test)
< Mem: 259584000 15634432 243949568 0 8388608 3756032
---
> Mem: 259584000 28954624 230629376 0 8388608 3756032
6c6
< MemFree: 238232 kB
---
> MemFree: 225224 kB
14c14
< Inact_target: 140 kB
---
> Inact_target: 4 kB
18c18
< LowFree: 238232 kB
---
> LowFree: 225224 kB
41c41
< sigqueue 29 29 132 1 1 1 : 252 126
---
> sigqueue 261 261 132 9 9 1 : 252 126
45,46c45,46
< inode_cache 88 88 480 11 11 1 : 124 62
< dentry_cache 180 180 128 6 6 1 : 252 126
---
> inode_cache 216 216 480 27 27 1 : 124 62
> dentry_cache 420 420 128 14 14 1 : 252 126
50,53c50,53
< mm_struct 48 48 160 2 2 1 : 252 126
< vm_area_struct 177 177 64 3 3 1 : 252 126
< fs_cache 118 118 64 2 2 1 : 252 126
< files_cache 18 18 416 2 2 1 : 124 62
---
> mm_struct 138 264 160 6 11 1 : 252 126
> vm_area_struct 354 354 64 6 6 1 : 252 126
> fs_cache 169 295 64 4 5 1 : 252 126
> files_cache 135 135 416 15 15 1 : 124 62
70c70
< size-1024 88 88 1024 22 22 1 : 124 62
---
> size-1024 208 208 1024 52 52 1 : 124 62
80c80
< size-32 226 226 32 2 2 1 : 252 126
---
> size-32 339 339 32 3 3 1 : 252 126
3. Keywords
mips, SMP, memory leak
4. Kernel version
Linux version 2.4.9
5. Output
(included as part of description)
6. testcase
(included as part of description)
7. Environment
7.1 software
None
7.2 Processor info
(NOTE *** cat /proc/cpuinfo does not print information about
both the CPUs ***)
cpu : MIPS
processor : 0
cpu model : SiByte SB1 V0.1
BogoMIPS : 332.59
processor : 1
cpu model : SiByte SB1 V0.1
BogoMIPS : 332.59
system type : SiByte unknown
byteorder : big endian
unaligned accesses : 0
wait instruction : no
microsecond timers : no
extra interrupt vector : yes
hardware watchpoint : no
VCED exceptions : not available
VCEI exceptions : not available
7.3 Module information
No modules.
7.4 Loaded driver and hardware information (/proc/ioports, /proc/iomem)
bash-2.04# cat /proc/ioports
bash-2.04# cat /proc/iomem
00000000-0fe94fff : System RAM
00100000-00267d77 : Kernel code
00299a40-002ad38f : Kernel data
7.5 PCI information
No PCI devices attached
7.6 SCSI information
No SCSI devices attached
7.7 Other information
Single user system with no networking.
Root file system is in the ramdisk.
8. Notes
When I did some investigation, it looked like d_lookup() is
not finding /proc/meminfo and /proc/slabinfo in the dcache and
it is doing d_alloc() to add these to the cache every time
cat /proc/meminfo or cat /proc/slabinfo is done. This looked odd
and I ran the same script on x86 based linux (running 2.4.2) and
I did not see MemFree (or any other caches) changing after the
test was run for an hour. I am not sure how this is architecture
dependent.
Thanks
Krishna Kondaka
Sanera Systems
