On Mon, Feb 15, 2016 at 01:02:55PM +0100, Johannes Thumshirn wrote: > > So I did > > make-bcache -B /dev/md5 > > echo /dev/md5 > /sys/fs/bcache/register > > > > and it fails: > > bash: page allocation failure: order:4, mode:0x2040d0 > > Is this system under some kind of memory preassure? Did this happen right > after boot or when the system was already running for quite some time? Uptime 17 days, it's a server that does a lot of I/O, but free shows I have 6GB available for buffer cache out of 8, so that shouldn't be too bad. Seems like I'm hitting an issue with memory fragmentation or a specific kind of memory not being available? (but I don't have any other kernel processes complaining about memory allocation failure, at least not consistently like here) On Mon, Feb 15, 2016 at 03:11:04AM -0900, Kent Overstreet wrote: > > and it fails: > > bash: page allocation failure: order:4, mode:0x2040d0 > > You want CONFIG_COMPACTION=y Good suggestion, but I already have it: gargamel:~# grep CONFIG_COMPACTION /boot/config-4.3.3-amd64-i915-volpreempt-20150421 CONFIG_COMPACTION=y Thanks for the replies, Marc -- "A mouse is a device used to point at the xterm you want to type in" - A.S.R. Microsoft is to operating systems .... .... what McDonalds is to gourmet cooking Home page: http://marc.merlins.org/ -- To unsubscribe from this list: send the line "unsubscribe linux-bcache" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html