jffs2 doesn't support swapping (swapon)

[gnu]

Opinions differ about whether it is *wise* to make paging/swapping space on NAND flash. But it is clear that the kernel should not be enforcing one person's opinion by making it *impossible* to swap to a file in NAND.

Currently (on software build update.1-rc2, MP G1G1 laptop), doing:

# cd /home/olpc

# dd if=/dev/zero of=swapfile bs=1024k count=20

# mkswap swapfile

# swapon swapfile

swapon: swapfile: Invalid argument

It fails. The same commands work fine on my FC6 system, using an ext3 root filesystem.

[I suspect that making as little as 20MB of swap space might help system performance, by letting it swap out modified but readonly pages. Rather than what currently happens, which is that those pages are stuck in RAM until the process dies. I'd like to test that theory, but there's this bug...]

[dilinger]

Given that we'd like to move away from jffs2 towards something that scales a bit better, I can't say that this is going to be given any sort of priority..

[hhardy]

Replying to gnu:

Opinions differ about whether it is *wise* to make paging/swapping space on NAND flash. But it is clear that the kernel should not be enforcing one person's opinion by making it *impossible* to swap to a file in NAND. Currently (on software build update.1-rc2, MP G1G1 laptop), doing: # cd /home/olpc # dd if=/dev/zero of=swapfile bs=1024k count=20 # mkswap swapfile # swapon swapfile swapon: swapfile: Invalid argument It fails. The same commands work fine on my FC6 system, using an ext3 root filesystem. [I suspect that making as little as 20MB of swap space might help system performance, by letting it swap out modified but readonly pages. Rather than what currently happens, which is that those pages are stuck in RAM until the process dies. I'd like to test that theory, but there's this bug...]

Having my 2 GB SD swap disabled has rendered my G1G1 unusable now. :(

Reflashing it means losing any and all modifications to the system. :( :(

Goodbye, fair Xephyr and Blackbox. Faretheewell, bounteous Opera. Good night, sweet CVS.

parting is such sweet sorrow...

[gregorio]

Milestone Never Assigned deleted