On 02/02/2013 06:17 PM, Simon Jeons wrote: > On Fri, 2013-02-01 at 09:13 -0600, Seth Jennings wrote: >> On 01/31/2013 07:39 PM, Simon Jeons wrote: >>> Hi Seth, >>> On Tue, 2013-01-29 at 15:40 -0600, Seth Jennings wrote: >> <snip> >>>> Performance, Kernel Building: >>>> >>>> Setup >>>> ======== >>>> Gentoo w/ kernel v3.7-rc7 >>>> Quad-core i5-2500 @ 3.3GHz >>>> 512MB DDR3 1600MHz (limited with mem=512m on boot) >>>> Filesystem and swap on 80GB HDD (about 58MB/s with hdparm -t) >>>> majflt are major page faults reported by the time command >>>> pswpin/out is the delta of pswpin/out from /proc/vmstat before and after >>>> then make -jN >>>> >>>> Summary >>>> ======== >>>> * Zswap reduces I/O and improves performance at all swap pressure levels. >>>> >>>> * Under heavy swaping at 24 threads, zswap reduced I/O by 76%, saving >>>> over 1.5GB of I/O, and cut runtime in half. >>> >>> How to get your benchmark? >> >> It's just kernel building. So "make" :) >> >> I intentionally choose this workload so people wouldn't have to jump >> through hoops to replicate the results. > > Thanks for your clarify. zswap is belong to in-kernel compression, > correct? then what's the difference between in-memory compression and > in-kernel compression? Dan made this distinction (possibly unintentionally) in his email. For me "in-kernel" means "done by the kernel" and "in-memory" means "stored in RAM". So it is compression of RAM pages done by the kernel and stored back in RAM. I sum up the functionality of zswap as "compressed swap caching", which I think better conveys what zswap does exactly. Seth -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>