Bug 247963
Summary: | Non all memory visible to system | ||
---|---|---|---|
Product: | Red Hat Enterprise Linux 4 | Reporter: | Tomasz Jaszowski <tjaszowski> |
Component: | kernel | Assignee: | Neil Horman <nhorman> |
Status: | CLOSED CANTFIX | QA Contact: | Martin Jenner <mjenner> |
Severity: | high | Docs Contact: | |
Priority: | low | ||
Version: | 4.4 | ||
Target Milestone: | --- | ||
Target Release: | --- | ||
Hardware: | All | ||
OS: | Linux | ||
Whiteboard: | |||
Fixed In Version: | Doc Type: | Bug Fix | |
Doc Text: | Story Points: | --- | |
Clone Of: | Environment: | ||
Last Closed: | 2007-10-04 17:14:55 UTC | Type: | --- |
Regression: | --- | Mount Type: | --- |
Documentation: | --- | CRM: | |
Verified Versions: | Category: | --- | |
oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
Cloudforms Team: | --- | Target Upstream Version: | |
Embargoed: |
Description
Tomasz Jaszowski
2007-07-12 10:43:56 UTC
anything? it's becoming critical... we tried to add more memory but some of it is still missing (256MB to over 700MB depending on machine...) sounds like the common "pci/video memory hole" not remapped by bios. Likely nothing that can be done about it from the OS standpoing. Please provide the e820 map and the output of /proc/iomem, and we can confirm. Thanks! ping. Any update here? PE6650: BIOS-provided physical RAM map: BIOS-e820: 0000000000000000 - 00000000000a0000 (usable) BIOS-e820: 0000000000100000 - 00000000cffe0000 (usable) BIOS-e820: 00000000cffe0000 - 00000000cffefc00 (ACPI data) BIOS-e820: 00000000cffefc00 - 00000000cffff000 (reserved) BIOS-e820: 00000000fec00000 - 00000000fec10000 (reserved) BIOS-e820: 00000000fee00000 - 00000000fee10000 (reserved) BIOS-e820: 00000000fff80000 - 0000000100000000 (reserved) 2431MB HIGHMEM available. 896MB LOWMEM available. :~> cat /proc/iomem 00000000-0009ffff : System RAM 000a0000-000bffff : Video RAM area 000c0000-000c7fff : Video ROM 000c8000-000c93ff : Adapter ROM 000c9800-000cabff : Adapter ROM 000cb000-000cb5ff : Adapter ROM 000f0000-000fffff : System ROM 00100000-cffdffff : System RAM 00100000-002d53e3 : Kernel code 002d53e4-0039337f : Kernel data cffe0000-cffefbff : ACPI Tables cffefc00-cfffefff : reserved e0000000-e7ffffff : PCI Bus #16 e0000000-e7ffffff : PCI Bus #17 e0000000-e7ffffff : 0000:17:00.0 e0000000-e7ffffff : MegaRAID: LSI Logic Corporation ed100000-ed3fffff : PCI Bus #16 ed1ff000-ed1fffff : 0000:16:01.0 ed300000-ed3fffff : PCI Bus #17 eff00000-eff0ffff : 0000:0a:02.0 eff00000-eff0ffff : tg3 eff10000-eff1ffff : 0000:0a:01.0 eff10000-eff1ffff : tg3 f0000000-f7ffffff : PCI Bus #04 f0000000-f7ffffff : PCI Bus #05 f0000000-f7ffffff : 0000:05:00.0 f0000000-f7ffffff : MegaRAID: LSI Logic Corporation fcd00000-fcffffff : PCI Bus #04 fcdff000-fcdfffff : 0000:04:01.0 fcf00000-fcffffff : PCI Bus #05 fd000000-fdffffff : 0000:00:04.0 fe100000-fe100fff : 0000:00:0f.2 fe100000-fe100fff : ohci_hcd fe101000-fe101fff : 0000:00:05.1 fe102000-fe102fff : 0000:00:04.0 feb00000-feb7ffff : 0000:00:05.1 feb80000-feb80fff : 0000:00:05.0 fec00000-fec0ffff : reserved fee00000-fee0ffff : reserved fff80000-ffffffff : reserved PE2650: BIOS-provided physical RAM map: BIOS-e820: 0000000000000000 - 00000000000a0000 (usable) BIOS-e820: 0000000000100000 - 00000000effe0000 (usable) BIOS-e820: 00000000effe0000 - 00000000effefc00 (ACPI data) BIOS-e820: 00000000effefc00 - 00000000effff000 (reserved) BIOS-e820: 00000000fec00000 - 00000000fec10000 (reserved) BIOS-e820: 00000000fee00000 - 00000000fee10000 (reserved) BIOS-e820: 00000000fff80000 - 0000000100000000 (reserved) 2943MB HIGHMEM available. 896MB LOWMEM available. :~> cat /proc/iomem 00000000-0009ffff : System RAM 000a0000-000bffff : Video RAM area 000c0000-000c7fff : Video ROM 000c8000-000cbfff : Adapter ROM 000cc000-000cc5ff : Adapter ROM 000f0000-000fffff : System ROM 00100000-effdffff : System RAM 00100000-002d53e3 : Kernel code 002d53e4-0039337f : Kernel data effe0000-effefbff : ACPI Tables effefc00-efffefff : reserved f0000000-f7ffffff : 0000:04:08.1 fcf00000-fcf0ffff : 0000:03:08.0 fcf00000-fcf0ffff : tg3 fcf10000-fcf1ffff : 0000:03:06.0 fcf10000-fcf1ffff : tg3 fd000000-fdffffff : 0000:00:0e.0 fe100000-fe100fff : 0000:00:0e.0 fe101000-fe101fff : 0000:00:04.1 feb00000-feb7ffff : 0000:00:04.1 feb80000-feb80fff : 0000:00:04.0 fec00000-fec0ffff : reserved fee00000-fee0ffff : reserved ff000000-ff000fff : 0000:00:0f.2 ff000000-ff000fff : ohci_hcd fff80000-ffffffff : reserved PE1850 (all mem visible) BIOS-provided physical RAM map: BIOS-e820: 0000000000000000 - 00000000000a0000 (usable) BIOS-e820: 0000000000100000 - 00000000bffc0000 (usable) BIOS-e820: 00000000bffc0000 - 00000000bffcfc00 (ACPI data) BIOS-e820: 00000000bffcfc00 - 00000000bffff000 (reserved) BIOS-e820: 00000000e0000000 - 00000000fec90000 (reserved) BIOS-e820: 00000000fed00000 - 00000000fed00400 (reserved) BIOS-e820: 00000000fee00000 - 00000000fee10000 (reserved) BIOS-e820: 00000000ffb00000 - 0000000100000000 (reserved) BIOS-e820: 0000000100000000 - 0000000140000000 (usable) 4224MB HIGHMEM available. 896MB LOWMEM available. :~> cd /opt/ Tue Sep 18 12:26:32 CEST 2007 grapp1:root:/opt> cat /proc/iomem 00000000-0009ffff : System RAM 000a0000-000bffff : Video RAM area 000c0000-000c7fff : Video ROM 000cb000-000cbfff : Adapter ROM 000cc000-000ccfff : Adapter ROM 000cd000-000d0bff : Adapter ROM 000d1000-000d31ff : Adapter ROM 000d3800-000d3dff : Adapter ROM 000f0000-000fffff : System ROM 00100000-bffbffff : System RAM 00100000-002d53e3 : Kernel code 002d53e4-0039337f : Kernel data bffc0000-bffcfbff : ACPI Tables bffcfc00-bfffefff : reserved c0000000-c00003ff : 0000:00:1f.1 c8000000-cfffffff : 0000:09:0d.0 d7f00000-d7f7ffff : 0000:09:05.1 d7fff000-d7ffffff : 0000:09:05.0 d8000000-d80fffff : PCI Bus #01 d8000000-d80fffff : PCI Bus #02 d80f0000-d80fffff : 0000:02:0e.0 d80f0000-d80fffff : MegaRAID: LSI Logic Corporation df5e0000-df5effff : 0000:09:0d.0 df5fec00-df5fecff : 0000:09:06.0 df5fec00-df5fecff : SiI680 df5ff000-df5fffff : 0000:09:05.1 df700000-dfbfffff : PCI Bus #05 df800000-df9fffff : PCI Bus #07 df8e0000-df8fffff : 0000:07:08.0 df8e0000-df8fffff : e1000 dfa00000-dfbfffff : PCI Bus #06 dfae0000-dfafffff : 0000:06:07.0 dfae0000-dfafffff : e1000 dfc00000-dfefffff : PCI Bus #01 dfd00000-dfefffff : PCI Bus #02 dfde0000-dfdfffff : 0000:02:0e.0 dfde0000-dfdfffff : MegaRAID: LSI Logic Corporation dff00000-dff003ff : 0000:00:1d.7 dff00000-dff003ff : ehci_hcd e0000000-fec8ffff : reserved fed00000-fed003ff : reserved fee00000-fee0ffff : reserved ffb00000-ffffffff : reserved Ahh, I was close. It does look like your bios has managed to re-map the missing ram from where your bios hole is located, however, its mapped it up above the 4GB boundary, so your kernel can't make use of it. You should be able to get it back by making use of the PAE kernel variant, which can utilize memory above 4GB. so i'll have to try with highmem kernel package yeah, the hugemem kernel should have the appropriate PAE configuration set, IIRC. hmm, strange thing. Due to some maintenance my colleague added some RAM to PE2650 and system saw 5.5GB instead of 6GB. He didn't changed kernel or anything else, just putted additional 2GB of memory, booted machine and checked... unfortunately he forgot to save e820 map and the output of /proc/iomem :/ My question is: if system was able to see 5.5GB of memory using standard smp kernel (not hugemem) why it has problem to address 4GB (or full 6GB)? Not so strange at all. System BIOS remapps the way it presents memory to the OS on boot up. Some bioses are intellegent about where they place memory, and weather or not they just let it get lost underneath I/O resources. Adding more memory likely caused the BIOS to place more memory in accessible space for the os. This does unfortunately suggest something troubling. If you can see 5.5GB of ram, you may already be running a kernel that has PAE enabled (I'll need to go check). If thats the case, then your memory visibility lies exclusively in the hands of the BIOS at this point, and there won't be anything we can do to claim more than it offers via the e820 map. we have tried to add memory to this server - and count was 5.5GB instead of 6GB root:> free total used free shared buffers cached Mem: 3375272 3359380 15892 0 11104 2836812 -/+ buffers/cache: 511464 2863808 Swap: 2008084 695516 1312568 Thu Oct 4 17:34:05 CEST 2007 root:> uname -a Linux huge-db 2.6.9-42.ELsmp #1 SMP Wed Jul 12 23:27:17 EDT 2006 i686 i686 i386 GNU/Linux i think that smp kernel has PAE included... little more info about kernel Linux version 2.6.9-42.ELsmp (bhcompile.redhat.com) (gcc version 3.4.6 20060404 (Red Hat 3.4.6-2)) #1 SMP Wed Jul 12 23:27:17 EDT 2006 yeah, it would seem that this isn't a PAE issue, but rather a bios mapping problem. This is going to have to be a cantfix. Best advice I can offer is to go to the system vendors web site and look for a bios update that enhances the way bios maps physical ram and io space. Sorry. |