Hi, I am seeing very slow dm-crypt writes on a machine where CPU, disk speed and even dm-crypt reads are normal. It appears that kcryptd is scheduled insufficiently on the CPU(s) when writing to dm-crypt devices. While reading, kcryptd is taking a lot of CPU time, most of the time (top). But when writing, kcryptd is taking a lot of pauses - I see intermittent activity where it uses the CPU for a few seconds, then pauses for a long time, then it's up again. Any idea what's going on? Writing a 1 GB file to dm-crypt takes 5 min (!): time cp /tmp/1GB_File /mnt/dm-crypt/tmp/ real 5m21.123s user 0m0.119s sys 0m7.762s Reading the same 1 GB file back from dm-crypt takes only 1.5 min: time cp /mnt/dm-crypt/tmp/1GB_File /tmp real 1m30.147s user 0m0.125s sys 0m7.522s Copying the file without dm-crypt takes about 1 min: time cp /tmp/1GB_File /tmp/Copy01 real 1m12.334s user 0m0.090s sys 0m5.856s This is Fedora 7, kernel 2.6.22.1-33.fc7 #1 SMP Mon Jul 23 17:33:07 EDT 2007 i686 i686 i386 GNU/Linux. Hardware is Intel 865G chipset, Pentium 4 CPU (HT), 2 GB RAM, ATA drive udma5. Thank you. --------------------------------------------------------------------- dm-crypt mailing list - http://www.saout.de/misc/dm-crypt/ To unsubscribe, e-mail: dm-crypt-unsubscribe@xxxxxxxx For additional commands, e-mail: dm-crypt-help@xxxxxxxx
