Messages in this thread | | | Date | Mon, 27 Mar 2006 10:23:22 -0600 | From | Richard Wohlstadter <> | Subject | 64bit 2.6.15.3 kernel not reporting free memory correctly? |
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Hi,
I have some servers running 64-bit kernels with 8g of memory and from what I understand of linux kernel memory management, it does not look like free memory is being reported correctly after some large jobs have run over time. For instance, here is what one my servers are reporting right now:
$ free
total used free shared buffers cached Mem: 8181360 5049828 3131532 0 243612 18256 -/+ buffers/cache: 4787960 3393400 Swap: 2048248 2496 2045752
$ cat /proc/meminfo
MemTotal: 8181360 kB MemFree: 3131672 kB Buffers: 243628 kB Cached: 18308 kB SwapCached: 0 kB Active: 1126408 kB Inactive: 3740400 kB HighTotal: 0 kB HighFree: 0 kB LowTotal: 8181360 kB LowFree: 3131672 kB SwapTotal: 2048248 kB SwapFree: 2045752 kB Dirty: 12 kB Writeback: 0 kB Mapped: 19764 kB Slab: 164564 kB CommitLimit: 6138928 kB Committed_AS: 44092 kB PageTables: 1064 kB VmallocTotal: 34359738367 kB VmallocUsed: 263376 kB VmallocChunk: 34359474699 kB
There are not many processes running right now, so I added all processes VmSize values which totals to: 332 meg
So the question is, if buffer/cache used totals 260meg and all processes running vmsize total 332 meg, then why is meminfo only reporting 3gig free. It seems that the kernel is keeping inactive pages from processes that have run in the past that are no longer running. I never see this type of issue on 32bit kernels so it seems this is 64-bit only(I've tried 2.6.14.3 and 2.6.15.3 kernels). Thanks to anyone who has any insight on this issue.
Rich Wohlstadter Washington University of St. Louis - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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