Running out of RAM in Ubuntu? Enable ZRAM


Whenever I ran out of RAM on a Linux system, I used to enable swap memory using the storage device to provide an extra bit of memory.  The main advantage is that it’s does not require extra hardware, but come at the cost of much slower access, and potential issues or wear and tear, unless you only use it temporary. This week-end, I compiled Arm Compute Library on ODROID-XU4Q board, and the first time it crashed because the system ran out of memory, so I enable swap on the eMMC flash module to restart and complete the build successfully. However, I was told it would have been better to enable ZRAM instead. So what is ZRAM? Wikipedia explains: zram, formerly called compcache, is a Linux kernel module for creating a compressed block device in RAM, i.e. a RAM disk, but with on-the-fly “disk” compression. So it’s similar to swap, expect it operates in RAM and compresses memory. It’s also possible […]

Linux 3.15 Released

Linus Torvalds announced the release of Linux Kernel 3.15 last Sunday: So I ended up doing an rc8 because I was a bit worried about some last-minute dcache fixes, but it turns out that nobody seemed to even notice those. We did have other issues during the week, though, so it was just as well. The futex fixes and cleanups may stand out, but as usual there’s various other random fixes since rc8 in there too: mainly drivers (drm, networking, sound, usb etc), networking, scheduling and perf tooling. But it’s all been fairly small and quiet, which *may* of course be due to the fact that last week was also the first week of the merge window for 3.16. That might have distracted some developers. I’m not entirely convinced I liked the overlap, but it seemed to work ok, and unless people scream really loudly (“Please don’t _ever_ do that again”) and give good reasons for doing so, I might end up doing that […]