Hello, On Thursday 26 January 2006 21:56, Jens Axboe wrote: > On Thu, Jan 26 2006, Edward Shishkin wrote: > > Jens Axboe wrote: > > >On Wed, Jan 25 2006, Hans Reiser wrote: > > >>Notice how CPU speed (and number of cpus) completely determines > > >>compression performance. > > >> > > >>cryptcompress refers to the reiser4 compression plugin, (unix file) > > >>refers to the reiser4 non-compressing plugin. > > >> > > >>Edward Shishkin wrote: > > >>>Here are the tests that vs asked for: > > >>>Creation (dd) of 20 tarfiles (the original 200M file is in ramfs) > > >>>Kernel: 2.6.15-mm4 + current git snapshot of reiser4 > > >>> > > >>>------------------------------------------ > > >>> > > >>>Laputa workstation > > >>>Uni Intel Pentium 4 (2.26 GHz) 512M RAM > > >>> > > >>>ext2: > > >>>real 2m, 15s > > >>>sys 0m, 14s > > >>> > > >>>reiser4(unix file) > > >>>real 2m, 7s > > >>>sys 0m, 23s > > >>> > > >>>reiser4(cryptcompress, lzo1, 64K) > > >>>real 2m, 13s > > >>>sys 0m, 11s > > > > > >Just curious - does your crypt plugin reside in user space? > > > > Nop. > > This is just wrappers for linux crypto api, zlib, etc.. > > so user time is zero and not interesting. > > Then why is the sys time lower than the "plain" writes on ext2 and > reiser4? Surely compressing isn't for free, yet the sys time is lower on > the compression write than the others.
I guess the compression was done by the background writeout daemon. CPU utilization numbers would say more than sys time. -- Alex. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/