Messages in this thread | | | Date | Sat, 15 Jul 2006 19:45:57 +0200 | From | Carsten Otto <> | Subject | Very poor IO performance (high CPU load), libata |
| |
Hello (again)!
System specs below.
My system sometimes[1] crashes in the sense that every HDD access is slow as hell and most of both CPUs' power is used for IO waiting. Then "top" shows more than 80% "wa" and the corresponding counter in /proc/stat increases a lot. When plotting these values with rrdtool I see up to 5% IO wait with normal behaviour and peaks with up to 40% under heavy load.
In the problem case the IO wait never drops below 40% no matter how light the HDD load is. Logging in into the system via SSH then takes more than two minutes and other tasks are equally slow.
Disabling AHCI/ACPI/SMP in the kernel did not help. I also tried several kernel versions including 2.6.16 to 2.6.18 (rc, mm).
/proc/interrupts shows a lot of interrupts for my network cards, but disabling the network does not solve the problem.
A reboot usually solves the problem for some time.
There might be a problem with my hardware (in a not yet determined device) causing this problem. But as long as I do not know what is wrong I still see the chance of a software error in the kernel.
System specs: - Mainboard with Intel 945p and iCH7R (Foxconn 945P7AA-8EKRS2) - Intel Pentium D 805 (Dual Core, 2.66 GHz, 1 MB cache each) - 4x Maxtor MaXLine III (300GB, 16MB Cache, SATA2)
[1] Sometimes: More than daily, at the moment I am lucky and noticed no problem for hours.
Thanks a lot, -- Carsten Otto c-otto@gmx.de www.c-otto.de [unhandled content-type:application/pgp-signature] | |