Files
linux/Documentation
Borislav Petkov dfb09f9b7a x86, amd: Avoid cache aliasing penalties on AMD family 15h
This patch provides performance tuning for the "Bulldozer" CPU. With its
shared instruction cache there is a chance of generating an excessive
number of cache cross-invalidates when running specific workloads on the
cores of a compute module.

This excessive amount of cross-invalidations can be observed if cache
lines backed by shared physical memory alias in bits [14:12] of their
virtual addresses, as those bits are used for the index generation.

This patch addresses the issue by clearing all the bits in the [14:12]
slice of the file mapping's virtual address at generation time, thus
forcing those bits the same for all mappings of a single shared library
across processes and, in doing so, avoids instruction cache aliases.

It also adds the command line option "align_va_addr=(32|64|on|off)" with
which virtual address alignment can be enabled for 32-bit or 64-bit x86
individually, or both, or be completely disabled.

This change leaves virtual region address allocation on other families
and/or vendors unaffected.

Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Link: http://lkml.kernel.org/r/1312550110-24160-2-git-send-email-bp@amd64.org
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2011-08-05 12:26:44 -07:00
..
2011-03-31 11:26:23 -03:00
2011-03-31 11:26:23 -03:00
2011-03-31 11:26:23 -03:00
2011-03-31 11:26:23 -03:00
2011-03-31 11:26:23 -03:00
2011-03-31 11:26:23 -03:00
2011-03-31 11:26:23 -03:00
2011-03-31 11:26:23 -03:00
2011-05-24 21:01:21 -04:00
2011-03-31 11:26:23 -03:00
2011-03-31 11:26:23 -03:00
2011-05-19 15:59:38 -07:00
2011-03-31 11:26:23 -03:00
2011-03-31 11:26:23 -03:00
2011-03-31 11:26:23 -03:00
2011-04-24 13:18:38 +02:00
2011-03-31 11:26:23 -03:00
2011-03-31 11:26:23 -03:00
2011-03-31 11:26:23 -03:00
2011-03-31 11:26:23 -03:00
2011-05-23 15:14:11 -07:00
2011-03-31 11:26:23 -03:00
2011-05-23 15:14:11 -07:00
2011-03-31 11:26:23 -03:00
2011-03-07 13:20:05 -08:00
2011-06-09 11:43:04 +10:00
2011-03-31 11:26:23 -03:00
2011-03-31 11:26:23 -03:00
2010-07-19 10:56:54 +02:00
2011-03-31 11:26:23 -03:00