linux_dsm_epyc7002/arch
Naveen N. Rao d62c8deeb6 powerpc/pseries: Provide vcpu dispatch statistics
For Shared Processor LPARs, the POWER Hypervisor maintains a
relatively static mapping of the LPAR processors (vcpus) to physical
processor chips (representing the "home" node) and tries to always
dispatch vcpus on their associated physical processor chip. However,
under certain scenarios, vcpus may be dispatched on a different
processor chip (away from its home node). The actual physical
processor number on which a certain vcpu is dispatched is available to
the guest in the 'processor_id' field of each DTL entry.

The guest can discover the home node of each vcpu through the
H_HOME_NODE_ASSOCIATIVITY(flags=1) hcall. The guest can also discover
the associativity of physical processors, as represented in the DTL
entry, through the H_HOME_NODE_ASSOCIATIVITY(flags=2) hcall.

These can then be compared to determine if the vcpu was dispatched on
its home node or not. If the vcpu was not dispatched on the home node,
it is possible to determine if the vcpu was dispatched in a different
chip, socket or drawer.

Introduce a procfs file /proc/powerpc/vcpudispatch_stats that can be
used to obtain these statistics. Writing '1' to this file enables
collecting the statistics, while writing '0' disables the statistics.
The statistics themselves are available by reading the procfs file. By
default, the DTLB log for each vcpu is processed 50 times a second so
as not to miss any entries. This processing frequency can be changed
through /proc/powerpc/vcpudispatch_stats_freq.

Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-07-04 22:27:09 +10:00
..
alpha treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 47 2019-05-24 17:27:13 +02:00
arc treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
arm The usual smattering of fixes and tunings that came in too late for the 2019-05-26 13:45:15 -07:00
arm64 The usual smattering of fixes and tunings that came in too late for the 2019-05-26 13:45:15 -07:00
c6x treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 36 2019-05-24 17:27:11 +02:00
csky treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
h8300 treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
hexagon treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
ia64 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 47 2019-05-24 17:27:13 +02:00
m68k treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 74 2019-05-24 17:36:47 +02:00
microblaze treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
mips treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 102 2019-05-24 17:39:00 +02:00
nds32 treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
nios2 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 13 2019-05-21 11:28:45 +02:00
openrisc treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
parisc treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
powerpc powerpc/pseries: Provide vcpu dispatch statistics 2019-07-04 22:27:09 +10:00
riscv treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 120 2019-05-24 17:39:02 +02:00
s390 KVM: s390: fix memory slot handling for KVM_SET_USER_MEMORY_REGION 2019-05-24 21:27:14 +02:00
sh treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
sparc treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 61 2019-05-24 17:36:45 +02:00
um treewide: Add SPDX license identifier for more missed files 2019-05-21 10:50:45 +02:00
unicore32 Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-05-19 10:23:24 -07:00
x86 The usual smattering of fixes and tunings that came in too late for the 2019-05-26 13:45:15 -07:00
xtensa treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
.gitignore
Kconfig Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-05-16 11:00:20 -07:00