I'm experiencing the same problem on a (arguably fairly underpowered, but dual-core) Intel Atom D510MO running Ubuntu 10.10 server (amd64). RAID1 on 2 x 2TB SATA drives, a single dm-crypt on top of that which contains a single LVM VG with two LVs for / and /home.
2 Clients (one with a 100MBit/s, the other with a 1GBit/s connection to the server, the server itself is connected with 1GBit/s) making backups on a SMB share on /home. If only the 100MBit/s-client is pumping out data, kcryptd uses ~30% CPU, iptraf showing ~90MBit/s traffic incoming, system responds quite nicely. If the 1Gbit/s-client starts to pump out data in parallel, kcryptd jumps to 100%, making the server virtually unusable as far as IO is concerned (takes ages to login or even start top, but it's fine if it doesn't need IO). Surprisingly, iptraf only jumps up to max. 120MBit/s incoming while this is happening, so there's not *that* much more traffic to handle, but now probably coming from 2 separate SMB threads. I found this recent commit to Linus' tree which could solve this problem. The dm-crypt scalability patch from Andi Kleen apparently was in development for quite a while and according to the commit message seems to address this problem. http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=c029772125594e31eb1a5ad9e0913724ed9891f2 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/529510 Title: kcryptd using 100% IO load -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
