[CentOS] 6.2 x86_64 "mtrr_cleanup: can not find optimal value"

Thu Apr 12 02:40:17 UTC 2012
Michael McNulty <ionosphere at live.com>




Hi,

I have server that has been running 5.x - 5.8 for a few years without issue and decided to move it to a fresh install of 6.2.  First thing I noticed is a good part of the log has these mtrr messages finally ending with
"mtrr_cleanup: can not find optimal value" and "please specify mtrr_gran_size/mtrr_chunk_size".  I have been searching around and reading the kernel docs but are bit lost on the impact.

The system CPU is a q6600 so it supports mtrr. It has 8gb of RAM and a G33 intel chipset (maximum memory is 8gb), 256mb onboard Intel video.  Problem exists with DVD 6.2 kernel and latest in yum update 2.6.32-220.7.1.el6.x86_64. 

If I disable the Bios "memory remap feature", mtrr appears to have found it settings.  But it says total ram covered is 7415M, so I lose some memory since when enabled it shows 8183M but mtrr fails.
A little concerned about putting this back into production with this but hope to get it resolved rather than reinstall 5.8. 

Will mtrr failing result in stability or performance loss?  Is there any performance loss disabling memory remap in bios other than losing 600k?  thx

Is this happening because the chipset only supports 8gb of memory and 
therefore mtrr cannot remap memory above 8gb? (assuming not since 
problem did not exist in 5.x centos)

-- Mike
 
Bios Memory remap feature: enabled

Apr 11 17:25:36  kernel: total RAM covered: 8183M
Apr 11 17:25:36  kernel: gran_size: 64K     chunk_size: 64K     num_reg: 8      lose cover RAM: 4865M
Apr 11 17:25:36  kernel: gran_size: 64K     chunk_size: 128K     num_reg: 8      lose cover RAM: 4865M
Apr 11 17:25:36  kernel: gran_size: 64K     chunk_size: 256K     num_reg: 8      lose cover RAM: 4865M
Apr 11 17:25:36  kernel: gran_size: 64K     chunk_size: 512K     num_reg: 8      lose cover RAM: 4865M
Apr 11 17:25:36  kernel: gran_size: 64K     chunk_size: 1M     num_reg: 8      lose cover RAM: 4865M
Apr 11 17:25:36  kernel: gran_size: 64K     chunk_size: 2M     num_reg: 8      lose cover RAM: 4864M
Apr 11 17:25:36  kernel: gran_size: 64K     chunk_size: 4M     num_reg: 8      lose cover RAM: 4864M
Apr 11 17:25:36  kernel: gran_size: 64K     chunk_size: 8M     num_reg: 8      lose cover RAM: 4864M
Apr 11 17:25:36  kernel: gran_size: 64K     chunk_size: 16M     num_reg: 8      lose cover RAM: 0G
Apr 11 17:25:36  kernel: gran_size: 64K     chunk_size: 32M     num_reg: 8      lose cover RAM: 0G
Apr 11 17:25:36  kernel: gran_size: 64K     chunk_size: 64M     num_reg: 8      lose cover RAM: 0G
Apr 11 17:25:36  kernel: gran_size: 64K     chunk_size: 128M     num_reg: 8      lose cover RAM: 0G
Apr 11 17:25:36  kernel: gran_size: 64K     chunk_size: 256M     num_reg: 8      lose cover RAM: 0G
Apr 11 17:25:36  kernel: *BAD*gran_size: 64K     chunk_size: 512M     num_reg: 8      lose cover RAM: -256M
Apr 11 17:25:36  kernel: gran_size: 64K     chunk_size: 1G     num_reg: 8      lose cover RAM: 0G
Apr 11 17:25:36  kernel: *BAD*gran_size: 64K     chunk_size: 2G     num_reg: 8      lose cover RAM: -1G
Apr 11 17:25:36  kernel: gran_size: 128K     chunk_size: 128K     num_reg: 8      lose cover RAM: 4865M
Apr 11 17:25:36  kernel: gran_size: 128K     chunk_size: 256K     num_reg: 8      lose cover RAM: 4865M
Apr 11 17:25:36  kernel: gran_size: 128K     chunk_size: 512K     num_reg: 8      lose cover RAM: 4865M
Apr 11 17:25:36  kernel: gran_size: 128K     chunk_size: 1M     num_reg: 8      lose cover RAM: 4865M
Apr 11 17:25:36  kernel: gran_size: 128K     chunk_size: 2M     num_reg: 8      lose cover RAM: 4864M
Apr 11 17:25:36  kernel: gran_size: 128K     chunk_size: 4M     num_reg: 8      lose cover RAM: 4864M
Apr 11 17:25:36  kernel: gran_size: 128K     chunk_size: 8M     num_reg: 8      lose cover RAM: 4864M
Apr 11 17:25:36  kernel: gran_size: 128K     chunk_size: 16M     num_reg: 8      lose cover RAM: 0G
Apr 11 17:25:36  kernel: gran_size: 128K     chunk_size: 32M     num_reg: 8      lose cover RAM: 0G
Apr 11 17:25:36  kernel: gran_size: 128K     chunk_size: 64M     num_reg: 8      lose cover RAM: 0G
Apr 11 17:25:36  kernel: gran_size: 128K     chunk_size: 128M     num_reg: 8      lose cover RAM: 0G
Apr 11 17:25:36  kernel: gran_size: 128K     chunk_size: 256M     num_reg: 8      lose cover RAM: 0G
Apr 11 17:25:36  kernel: *BAD*gran_size: 128K     chunk_size: 512M     num_reg: 8      lose cover RAM: -256M
Apr 11 17:25:36  kernel: gran_size: 128K     chunk_size: 1G     num_reg: 8      lose cover RAM: 0G
Apr 11 17:25:36  kernel: *BAD*gran_size: 128K     chunk_size: 2G     num_reg: 8      lose cover RAM: -1G
Apr 11 17:25:36  kernel: gran_size: 256K     chunk_size: 256K     num_reg: 8      lose cover RAM: 4865M
Apr 11 17:25:36  kernel: gran_size: 256K     chunk_size: 512K     num_reg: 8      lose cover RAM: 4865M
Apr 11 17:25:36  kernel: gran_size: 256K     chunk_size: 1M     num_reg: 8      lose cover RAM: 4865M
Apr 11 17:25:36  kernel: gran_size: 256K     chunk_size: 2M     num_reg: 8      lose cover RAM: 4864M
Apr 11 17:25:36  kernel: gran_size: 256K     chunk_size: 4M     num_reg: 8      lose cover RAM: 4864M
Apr 11 17:25:36  kernel: gran_size: 256K     chunk_size: 8M     num_reg: 8      lose cover RAM: 4864M
Apr 11 17:25:36  kernel: gran_size: 256K     chunk_size: 16M     num_reg: 8      lose cover RAM: 0G
Apr 11 17:25:36  kernel: gran_size: 256K     chunk_size: 32M     num_reg: 8      lose cover RAM: 0G
Apr 11 17:25:36  kernel: gran_size: 256K     chunk_size: 64M     num_reg: 8      lose cover RAM: 0G
Apr 11 17:25:36  kernel: gran_size: 256K     chunk_size: 128M     num_reg: 8      lose cover RAM: 0G
Apr 11 17:25:36  kernel: gran_size: 256K     chunk_size: 256M     num_reg: 8      lose cover RAM: 0G
Apr 11 17:25:36  kernel: *BAD*gran_size: 256K     chunk_size: 512M     num_reg: 8      lose cover RAM: -256M
Apr 11 17:25:36  kernel: gran_size: 256K     chunk_size: 1G     num_reg: 8      lose cover RAM: 0G
Apr 11 17:25:36  kernel: *BAD*gran_size: 256K     chunk_size: 2G     num_reg: 8      lose cover RAM: -1G
Apr 11 17:25:36  kernel: gran_size: 512K     chunk_size: 512K     num_reg: 8      lose cover RAM: 4865M
Apr 11 17:25:36  kernel: gran_size: 512K     chunk_size: 1M     num_reg: 8      lose cover RAM: 4865M
Apr 11 17:25:36  kernel: gran_size: 512K     chunk_size: 2M     num_reg: 8      lose cover RAM: 4864M
Apr 11 17:25:36  kernel: gran_size: 512K     chunk_size: 4M     num_reg: 8      lose cover RAM: 4864M
Apr 11 17:25:36  kernel: gran_size: 512K     chunk_size: 8M     num_reg: 8      lose cover RAM: 4864M
Apr 11 17:25:36  kernel: gran_size: 512K     chunk_size: 16M     num_reg: 8      lose cover RAM: 0G
Apr 11 17:25:36  kernel: gran_size: 512K     chunk_size: 32M     num_reg: 8      lose cover RAM: 0G
Apr 11 17:25:36  kernel: gran_size: 512K     chunk_size: 64M     num_reg: 8      lose cover RAM: 0G
Apr 11 17:25:36  kernel: gran_size: 512K     chunk_size: 128M     num_reg: 8      lose cover RAM: 0G
Apr 11 17:25:36  kernel: gran_size: 512K     chunk_size: 256M     num_reg: 8      lose cover RAM: 0G
Apr 11 17:25:36  kernel: *BAD*gran_size: 512K     chunk_size: 512M     num_reg: 8      lose cover RAM: -256M
Apr 11 17:25:36  kernel: gran_size: 512K     chunk_size: 1G     num_reg: 8      lose cover RAM: 0G
Apr 11 17:25:36  kernel: *BAD*gran_size: 512K     chunk_size: 2G     num_reg: 8      lose cover RAM: -1G
Apr 11 17:25:36  kernel: gran_size: 1M     chunk_size: 1M     num_reg: 8      lose cover RAM: 4865M
Apr 11 17:25:36  kernel: gran_size: 1M     chunk_size: 2M     num_reg: 8      lose cover RAM: 4864M
Apr 11 17:25:36  kernel: gran_size: 1M     chunk_size: 4M     num_reg: 8      lose cover RAM: 4864M
Apr 11 17:25:36  kernel: gran_size: 1M     chunk_size: 8M     num_reg: 8      lose cover RAM: 4864M
Apr 11 17:25:36  kernel: gran_size: 1M     chunk_size: 16M     num_reg: 8      lose cover RAM: 0G
Apr 11 17:25:36  kernel: gran_size: 1M     chunk_size: 32M     num_reg: 8      lose cover RAM: 0G
Apr 11 17:25:36  kernel: gran_size: 1M     chunk_size: 64M     num_reg: 8      lose cover RAM: 0G
Apr 11 17:25:36  kernel: gran_size: 1M     chunk_size: 128M     num_reg: 8      lose cover RAM: 0G
Apr 11 17:25:36  kernel: gran_size: 1M     chunk_size: 256M     num_reg: 8      lose cover RAM: 0G
Apr 11 17:25:36  kernel: *BAD*gran_size: 1M     chunk_size: 512M     num_reg: 8      lose cover RAM: -256M
Apr 11 17:25:36  kernel: gran_size: 1M     chunk_size: 1G     num_reg: 8      lose cover RAM: 0G
Apr 11 17:25:36  kernel: *BAD*gran_size: 1M     chunk_size: 2G     num_reg: 8      lose cover RAM: -1G
Apr 11 17:25:36  kernel: gran_size: 2M     chunk_size: 2M     num_reg: 8      lose cover RAM: 4865M
Apr 11 17:25:36  kernel: gran_size: 2M     chunk_size: 4M     num_reg: 8      lose cover RAM: 4865M
Apr 11 17:25:36  kernel: gran_size: 2M     chunk_size: 8M     num_reg: 8      lose cover RAM: 4865M
Apr 11 17:25:36  kernel: gran_size: 2M     chunk_size: 16M     num_reg: 8      lose cover RAM: 1M
Apr 11 17:25:36  kernel: gran_size: 2M     chunk_size: 32M     num_reg: 8      lose cover RAM: 1M
Apr 11 17:25:36  kernel: gran_size: 2M     chunk_size: 64M     num_reg: 8      lose cover RAM: 1M
Apr 11 17:25:36  kernel: gran_size: 2M     chunk_size: 128M     num_reg: 8      lose cover RAM: 1M
Apr 11 17:25:36  kernel: gran_size: 2M     chunk_size: 256M     num_reg: 8      lose cover RAM: 1M
Apr 11 17:25:36  kernel: *BAD*gran_size: 2M     chunk_size: 512M     num_reg: 8      lose cover RAM: -255M
Apr 11 17:25:36  kernel: gran_size: 2M     chunk_size: 1G     num_reg: 8      lose cover RAM: 1M
Apr 11 17:25:36  kernel: *BAD*gran_size: 2M     chunk_size: 2G     num_reg: 8      lose cover RAM: -1023M
Apr 11 17:25:36  kernel: gran_size: 4M     chunk_size: 4M     num_reg: 8      lose cover RAM: 771M
Apr 11 17:25:36  kernel: gran_size: 4M     chunk_size: 8M     num_reg: 8      lose cover RAM: 4867M
Apr 11 17:25:36  kernel: gran_size: 4M     chunk_size: 16M     num_reg: 8      lose cover RAM: 3M
Apr 11 17:25:36  kernel: gran_size: 4M     chunk_size: 32M     num_reg: 8      lose cover RAM: 3M
Apr 11 17:25:36  kernel: gran_size: 4M     chunk_size: 64M     num_reg: 8      lose cover RAM: 3M
Apr 11 17:25:36  kernel: gran_size: 4M     chunk_size: 128M     num_reg: 8      lose cover RAM: 3M
Apr 11 17:25:36  kernel: gran_size: 4M     chunk_size: 256M     num_reg: 8      lose cover RAM: 3M
Apr 11 17:25:36  kernel: *BAD*gran_size: 4M     chunk_size: 512M     num_reg: 8      lose cover RAM: -253M
Apr 11 17:25:36  kernel: gran_size: 4M     chunk_size: 1G     num_reg: 8      lose cover RAM: 3M
Apr 11 17:25:36  kernel: *BAD*gran_size: 4M     chunk_size: 2G     num_reg: 8      lose cover RAM: -1021M
Apr 11 17:25:36  kernel: gran_size: 8M     chunk_size: 8M     num_reg: 8      lose cover RAM: 263M
Apr 11 17:25:36  kernel: gran_size: 8M     chunk_size: 16M     num_reg: 8      lose cover RAM: 263M
Apr 11 17:25:36  kernel: gran_size: 8M     chunk_size: 32M     num_reg: 7      lose cover RAM: 7M
Apr 11 17:25:36  kernel: gran_size: 8M     chunk_size: 64M     num_reg: 7      lose cover RAM: 7M
Apr 11 17:25:36  kernel: gran_size: 8M     chunk_size: 128M     num_reg: 7      lose cover RAM: 7M
Apr 11 17:25:36  kernel: gran_size: 8M     chunk_size: 256M     num_reg: 7      lose cover RAM: 7M
Apr 11 17:25:36  kernel: gran_size: 8M     chunk_size: 512M     num_reg: 8      lose cover RAM: 7M
Apr 11 17:25:36  kernel: gran_size: 8M     chunk_size: 1G     num_reg: 7      lose cover RAM: 7M
Apr 11 17:25:36  kernel: gran_size: 8M     chunk_size: 2G     num_reg: 8      lose cover RAM: 7M
Apr 11 17:25:36  kernel: gran_size: 16M     chunk_size: 16M     num_reg: 8      lose cover RAM: 263M
Apr 11 17:25:36  kernel: gran_size: 16M     chunk_size: 32M     num_reg: 7      lose cover RAM: 7M
Apr 11 17:25:36  kernel: gran_size: 16M     chunk_size: 64M     num_reg: 7      lose cover RAM: 7M
Apr 11 17:25:36  kernel: gran_size: 16M     chunk_size: 128M     num_reg: 7      lose cover RAM: 7M
Apr 11 17:25:36  kernel: gran_size: 16M     chunk_size: 256M     num_reg: 7      lose cover RAM: 7M
Apr 11 17:25:36  kernel: gran_size: 16M     chunk_size: 512M     num_reg: 8      lose cover RAM: 7M
Apr 11 17:25:36  kernel: gran_size: 16M     chunk_size: 1G     num_reg: 7      lose cover RAM: 7M
Apr 11 17:25:36  kernel: gran_size: 16M     chunk_size: 2G     num_reg: 8      lose cover RAM: 7M
Apr 11 17:25:36  kernel: gran_size: 32M     chunk_size: 32M     num_reg: 8      lose cover RAM: 23M
Apr 11 17:25:36  kernel: gran_size: 32M     chunk_size: 64M     num_reg: 7      lose cover RAM: 23M
Apr 11 17:25:36  kernel: gran_size: 32M     chunk_size: 128M     num_reg: 7      lose cover RAM: 23M
Apr 11 17:25:36  kernel: gran_size: 32M     chunk_size: 256M     num_reg: 7      lose cover RAM: 23M
Apr 11 17:25:36  kernel: gran_size: 32M     chunk_size: 512M     num_reg: 8      lose cover RAM: 23M
Apr 11 17:25:36  kernel: gran_size: 32M     chunk_size: 1G     num_reg: 7      lose cover RAM: 23M
Apr 11 17:25:36  kernel: gran_size: 32M     chunk_size: 2G     num_reg: 8      lose cover RAM: 23M
Apr 11 17:25:36  kernel: gran_size: 64M     chunk_size: 64M     num_reg: 7      lose cover RAM: 55M
Apr 11 17:25:36  kernel: gran_size: 64M     chunk_size: 128M     num_reg: 7      lose cover RAM: 55M
Apr 11 17:25:36  kernel: gran_size: 64M     chunk_size: 256M     num_reg: 7      lose cover RAM: 55M
Apr 11 17:25:36  kernel: gran_size: 64M     chunk_size: 512M     num_reg: 8      lose cover RAM: 55M
Apr 11 17:25:36  kernel: gran_size: 64M     chunk_size: 1G     num_reg: 7      lose cover RAM: 55M
Apr 11 17:25:36  kernel: gran_size: 64M     chunk_size: 2G     num_reg: 8      lose cover RAM: 55M
Apr 11 17:25:36  kernel: gran_size: 128M     chunk_size: 128M     num_reg: 6      lose cover RAM: 119M
Apr 11 17:25:36  kernel: gran_size: 128M     chunk_size: 256M     num_reg: 7      lose cover RAM: 119M
Apr 11 17:25:36  kernel: gran_size: 128M     chunk_size: 512M     num_reg: 8      lose cover RAM: 119M
Apr 11 17:25:36  kernel: gran_size: 128M     chunk_size: 1G     num_reg: 7      lose cover RAM: 119M
Apr 11 17:25:36  kernel: gran_size: 128M     chunk_size: 2G     num_reg: 8      lose cover RAM: 119M
Apr 11 17:25:36  kernel: gran_size: 256M     chunk_size: 256M     num_reg: 5      lose cover RAM: 247M
Apr 11 17:25:36  kernel: gran_size: 256M     chunk_size: 512M     num_reg: 5      lose cover RAM: 247M
Apr 11 17:25:36  kernel: gran_size: 256M     chunk_size: 1G     num_reg: 5      lose cover RAM: 247M
Apr 11 17:25:36  kernel: gran_size: 256M     chunk_size: 2G     num_reg: 6      lose cover RAM: 247M
Apr 11 17:25:36  kernel: gran_size: 512M     chunk_size: 512M     num_reg: 4      lose cover RAM: 503M
Apr 11 17:25:36  kernel: gran_size: 512M     chunk_size: 1G     num_reg: 5      lose cover RAM: 503M
Apr 11 17:25:36  kernel: gran_size: 512M     chunk_size: 2G     num_reg: 6      lose cover RAM: 503M
Apr 11 17:25:36  kernel: gran_size: 1G     chunk_size: 1G     num_reg: 3      lose cover RAM: 1015M
Apr 11 17:25:36  kernel: gran_size: 1G     chunk_size: 2G     num_reg: 3      lose cover RAM: 1015M
Apr 11 17:25:36  kernel: gran_size: 2G     chunk_size: 2G     num_reg: 2      lose cover RAM: 2039M
Apr 11 17:25:36  kernel: mtrr_cleanup: can not find optimal value
Apr 11 17:25:36  kernel: please specify mtrr_gran_size/mtrr_chunk_size

cat /proc/mtrr
reg00: base=0x0d0000000 ( 3328MB), size=  256MB, count=1: uncachable
reg01: base=0x0e0000000 ( 3584MB), size=  512MB, count=1: uncachable
reg02: base=0x000000000 (    0MB), size= 8192MB, count=1: write-back
reg03: base=0x200000000 ( 8192MB), size=  512MB, count=1: write-back
reg04: base=0x220000000 ( 8704MB), size=  256MB, count=1: write-back
reg05: base=0x0cf700000 ( 3319MB), size=    1MB, count=1: uncachable
reg06: base=0x0cf800000 ( 3320MB), size=    8MB, count=1: uncachable

cat /proc/meminfo
MemTotal:        8050140 kB

Now with:  Bios Memory remap feature: disabled


cat /proc/meminfo
MemTotal:        7276000 kB

Apr 11 15:33:41 ns2 kernel: total RAM covered: 7415M

Apr 11 15:33:41 ns2 kernel: Found optimal setting for mtrr clean up

Apr 11 15:33:41 ns2 kernel: gran_size: 64K     chunk_size: 16M     num_reg: 6      lose cover RAM: 0G


/proc/mtrr  (bios memory remap disabled)

reg00: base=0x000000000 (    0MB), size= 2048MB, count=1: write-back

reg01: base=0x080000000 ( 2048MB), size= 1024MB, count=1: write-back

reg02: base=0x0c0000000 ( 3072MB), size=  256MB, count=1: write-back

reg03: base=0x0cf700000 ( 3319MB), size=    1MB, count=1: uncachable

reg04: base=0x0cf800000 ( 3320MB), size=    8MB, count=1: uncachable

reg05: base=0x100000000 ( 4096MB), size= 4096MB, count=1: write-back

reg06: base=0x0d0000000 ( 3328MB), size=  256MB, count=1: write-combining