On 01/04/2011 02:40 PM, Jiri Slaby wrote:Ok, bisected down to: 16dc39c98a6ca56a27f22f7ac6731d8223237a2e is first bad commit commit 16dc39c98a6ca56a27f22f7ac6731d8223237a2e Author: Len Brown <len.brown@intel.com> Date: Thu Dec 16 23:12:23 2010 -0500 ACPI: use ioremap_cache() Although the temporary boot-time ACPI table mappings were set up with CPU caching enabled, the permanent table mappings and AML run-time region memory accesses were set up with ioremap(), which on x86 is a synonym for ioremap_nocache(). Changing this to ioremap_cache() improves performance as seen when accessing the tables via acpidump, or /sys/firmware/acpi/tables. It should also improve AML run-time performance. No change on ia64. Reported-by: Jack Steiner <steiner@sgi.com> Signed-off-by: Len Brown <len.brown@intel.com> :040000 040000 be35c5e8f214f10f94688c1a27f33ecfb8505220 52581222d0edf190f160f3e5aa5d2c1af8e76988 M arch :040000 040000 ccdca0d41938b8312e946cde3c01c59b32d1c17c 96ccf2357f2ac4a31d19cc41f5728d9f87b6cac0 M drivers Revert of that patch fixes the problem. regards, -- js --
