Greg, Peter, the s390 z13 machines expose yet another topology level which would be on top of the already existing "book" scheduling domain, which is currently only used by s390.
Therefore I would like to introduce a new "drawer" level to the topology sysfs code. The scheduler code itself does not need any changes to support this, since I can introduce as many scheduling domains as I like within architecture code. However the sysfs representation is common code. The first patch introduces the files /sys/devices/system/cpu/cpuX/topology/drawer_id /sys/devices/system/cpu/cpuX/topology/drawer_siblings /sys/devices/system/cpu/cpuX/topology/drawer_siblings_list if CONFIG_SCHED_DRAWER is enabled. The second patch implements support for the new topology level on s390. Performance measurements did show a performance increase of up to 8%, while there don't seem to be any negative impacts. If this is acceptable I'd like to add these patches to the s390 tree for the next merge window. For reference the z13 machine is described here: www.redbooks.ibm.com/redbooks/pdfs/sg248251.pdf Chapter 2 (or 2.2) gives a brief overview of what I'm talking about. Heiko Carstens (2): topology/sysfs: provide drawer id and siblings attributes s390/topology: add drawer scheduling domain level Documentation/cputopology.txt | 40 ++++++++++++++++++++++++++++++++-------- arch/s390/Kconfig | 4 ++++ arch/s390/include/asm/topology.h | 4 ++++ arch/s390/kernel/topology.c | 33 +++++++++++++++++++++++++++------ arch/s390/numa/mode_emu.c | 25 ++++++++++++++++++++----- drivers/base/topology.c | 13 +++++++++++++ 6 files changed, 100 insertions(+), 19 deletions(-) -- 2.6.6
