Steven Keuchel

The 768MB arc_max was for a vmalloc of 1024MB and I was using zfs 0.7.12 when I wrote that, but since then I have switched to 0.8 (with Thumb2 patches from github). I have looked at this again (now with 0.8), and it seems the situation has indeed changed. When looking at vmalloc of zfs (spl actually) via /proc/vmallocinfo it seems to hover around 100-150MB with about 220MB being the highest I've seen and also the total address space occupied by all allocations has always been under 300MB and usually far below. So it seems rather compact with only little fragmentation happening. So zfs appears to use less vmalloc than I assumed and more lowmem, so I will have to revise my settings, because they clearly don't make sense anymore.

The 768MB arc_max was for a vmalloc of 1024MB and I was using zfs 0.7.12 when I wrote that, but since then I have switched to 0.8 (with Thumb2 patches from github). I have looked at this again (now with 0.8), and it seems the situation has indeed changed. When looking at vmalloc of zfs (spl actually) via /proc/vmallocinfo it seems to hover around 100-150MB with about 220MB being the highest I've seen and also the total address space occupied by all allocations has always been under 300MB and usually far below. So it seems rather compact with only little fragmentation happening. So zfs appears to use less vmalloc than I assumed and more lowmem, so I will have to revise my settings, because they clearly don't make sense anymore.