How to limit memory usage

[OlaJi]

Hi,

I'm running transmission on a WD MyBook WE (ARM architecture) and I experience that the device halts with an out-of-memory condition when I start multiple heavy downloads. What settings can I modify to limit/minimize the memory usage by Transmission? (open-file-limit?, peer-limit-?)

TYIA

[phillipsjk]

You mean literally, as in: fitting inside 32MB of RAM?

http://martin.hinner.info/mybook/

I think I would reduce the number of open files (even at the OS level), but that would increase disk access. You probably need a swap partition of at least 64MB, but that will also be affected by disk access. I think peer information that won't fit in memory will find it's way to swap. If you can't create a new partition, a swap file may have to suffice.

[OlaJi]

Hi,

There is actually already a swap-partition of 104 MB. If I understand the log correctly the swap is not used (which puzzles me) but the transmission daemon runs out of physical memory (page allocation failure). Here is the message log just before the MyBook halts, maybe someone here that understands this better can hint to as what's going on:

Dec 2 23:34:30 MyBookWorld user.warn kernel: transmission-da: page allocation failure. order:1, mode:0x20
Dec 2 23:34:30 MyBookWorld user.warn kernel: Mem-info:
Dec 2 23:34:30 MyBookWorld user.warn kernel: DMA per-cpu:
Dec 2 23:34:30 MyBookWorld user.warn kernel: cpu 0 hot: high 6, batch 1 used:3
Dec 2 23:34:30 MyBookWorld user.warn kernel: cpu 0 cold: high 2, batch 1 used:1
Dec 2 23:34:30 MyBookWorld user.warn kernel: DMA32 per-cpu: empty
Dec 2 23:34:30 MyBookWorld user.warn kernel: Normal per-cpu: empty
Dec 2 23:34:30 MyBookWorld user.warn kernel: HighMem per-cpu: empty
Dec 2 23:34:30 MyBookWorld user.warn kernel: Free pages: 1064kB (0kB HighMem)
Dec 2 23:34:30 MyBookWorld user.warn kernel: Active:2598 inactive:1895 dirty:389 writeback:0 unstable:0 free:266 slab:2313 mapped:2198 pagetables:63
Dec 2 23:34:30 MyBookWorld user.warn kernel: DMA free:1064kB min:724kB low:904kB high:1084kB active:10392kB inactive:7580kB present:32768kB pages_scanned:0 all_unreclaimable? no
Dec 2 23:34:30 MyBookWorld user.warn kernel: lowmem_reserve[]: 0 0 0 0
Dec 2 23:34:30 MyBookWorld user.warn kernel: DMA32 free:0kB min:0kB low:0kB high:0kB active:0kB inactive:0kB present:0kB pages_scanned:0 all_unreclaimable? no
Dec 2 23:34:30 MyBookWorld user.warn kernel: lowmem_reserve[]: 0 0 0 0
Dec 2 23:34:30 MyBookWorld user.warn kernel: Normal free:0kB min:0kB low:0kB high:0kB active:0kB inactive:0kB present:0kB pages_scanned:0 all_unreclaimable? no
Dec 2 23:34:30 MyBookWorld user.warn kernel: lowmem_reserve[]: 0 0 0 0
Dec 2 23:34:30 MyBookWorld user.warn kernel: HighMem free:0kB min:128kB low:128kB high:128kB active:0kB inactive:0kB present:0kB pages_scanned:0 all_unreclaimable? no
Dec 2 23:34:30 MyBookWorld user.warn kernel: lowmem_reserve[]: 0 0 0 0
Dec 2 23:34:30 MyBookWorld user.warn kernel: DMA: 232*4kB 1*8kB 0*16kB 0*32kB 0*64kB 1*128kB 0*256kB 0*512kB 0*1024kB 0*2048kB = 1064kB
Dec 2 23:34:30 MyBookWorld user.warn kernel: DMA32: empty
Dec 2 23:34:30 MyBookWorld user.warn kernel: Normal: empty
Dec 2 23:34:30 MyBookWorld user.warn kernel: HighMem: empty
Dec 2 23:34:30 MyBookWorld user.warn kernel: Swap cache: add 9133, delete 9003, find 2492/3275, race 0+1
Dec 2 23:34:30 MyBookWorld user.warn kernel: Free swap = 102696kB
Dec 2 23:34:30 MyBookWorld user.warn kernel: Total swap = 104312kB
Dec 2 23:34:30 MyBookWorld user.warn kernel: Free swap: 102696kB
Dec 2 23:34:30 MyBookWorld user.warn kernel: 8192 pages of RAM
Dec 2 23:34:30 MyBookWorld user.warn kernel: 372 free pages
Dec 2 23:34:30 MyBookWorld user.warn kernel: 691 reserved pages
Dec 2 23:34:30 MyBookWorld user.warn kernel: 2313 slab pages
Dec 2 23:34:30 MyBookWorld user.warn kernel: 3590 pages shared
Dec 2 23:34:30 MyBookWorld user.warn kernel: 130 pages swap cached

[jch]

Memory usage should be much improved in 1.80 (try the current SVN).

--Juliusz