On Fri, Jun 05, 2020 at 05:55:26PM +0200, Igor Raits wrote: > On Fri, 2020-06-05 at 15:11 +0100, Richard W.M. Jones wrote: > > I'm unclear: that ~50M is still in RAM? Or it's compressed on a disk > > somewhere? > > IIUC, it takes some part of the RAM and just compresses it on the fly. > For example, I have 32G memory on my laptop and when I enable zram > device, I basically have 23G listed in free as memory and 11G as the > swap. And that 11G is supposed to be compressed memory (in avg cases > with 2:1 ration). > > Of course, as part of this change, it will be made that it can't take > more than 4G no matter what by default. Thanks - the fact that the primary swap partition now lives in RAM is what I was missing. But let's say we also add a lower priority disk swap, then my next question ... > > Also does the swap partition on disk contain compressed pages, or > > uncompressed pages, or a mix of both? > > With zram there is no partition on disk, or was this question about > something else? ... means: Does this secondary swap partition (on disk) contain swapped out zram pages? Or uncompressed pages? (Or maybe the question just makes no sense, I don't really know.) > > Also what is the compression algorithm? zlib or zstd or something > > else? > > zramctl shows ALGORITHM > > NAME ALGORITHM DISKSIZE DATA COMPR TOTAL STREAMS MOUNTPOINT > /dev/zram0 lzo-rle 11.7G 4K 74B 12K 8 [SWAP] > > So it is lzo-rle by default, but it should be possible to override this > algorithm. There is an RFE for this already at zram-generator github. Interesting, thanks. It looks like zstd is an alternative, although I don't know which will be better/faster. Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com virt-top is 'top' for virtual machines. Tiny program with many powerful monitoring features, net stats, disk stats, logging, etc. http://people.redhat.com/~rjones/virt-top _______________________________________________ devel mailing list -- devel@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe send an email to devel-leave@xxxxxxxxxxxxxxxxxxxxxxx Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/devel@xxxxxxxxxxxxxxxxxxxxxxx
