GNOME Shell started to crawl, using up all RAM and swapping all the time, for seemingly no good reason. So I made some hardware purchases. Or rather, I jumped at the opportunity to make some hardware purchases.
$ df -h . Filesystem Size Used Avail Use% Mounted on /dev/sda8 525G 133G 366G 27% /home $ free -h total used free shared buffers cached Mem: 11G 5.5G 6.1G 379M 687M 2.7G -/+ buffers/cache: 2.2G 9.5G Swap: 4.0G 0B 4.0G
Thrice as much disk space than before. Twice as much RAM than before. Not too fancy, but wheee!
It turned out to be rather unnecessary, though: the reason for GNOME Shell's crawliness was that Mesa had been using fallback software path for OpenGL rendering rather than hardware; and this was because Mesa needed a newer kernel. I came to know of this because I attempted to launch an Android emulator, which failed to launch with Mesa-related error message, even though I had disabled hardware rendering in emulator settings. Installing a newer kernel made things normal.
Depending on how you're looking at it, there could be a moral somewhere in this story. The urge to get an SSD has been contained though – for now.