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| author | Nysal Jan K.A <[email protected]> | 2024-07-31 08:31:12 +0530 |
|---|---|---|
| committer | Michael Ellerman <[email protected]> | 2024-08-13 10:31:24 +1000 |
| commit | 6c17ea1f3eaa330d445ac14a9428402ce4e3055e (patch) | |
| tree | 4e5e903107d323ebe0ea0be31f8e1f0fce17f5ad /tools/testing/selftests/bpf/prog_tests/autoload.c | |
| parent | e7e846dc6c73fbc94ae8b4ec20d05627646416f2 (diff) | |
cpu/SMT: Enable SMT only if a core is online
If a core is offline then enabling SMT should not online CPUs of
this core. By enabling SMT, what is intended is either changing the SMT
value from "off" to "on" or setting the SMT level (threads per core) from a
lower to higher value.
On PowerPC the ppc64_cpu utility can be used, among other things, to
perform the following functions:
ppc64_cpu --cores-on # Get the number of online cores
ppc64_cpu --cores-on=X # Put exactly X cores online
ppc64_cpu --offline-cores=X[,Y,...] # Put specified cores offline
ppc64_cpu --smt={on|off|value} # Enable, disable or change SMT level
If the user has decided to offline certain cores, enabling SMT should
not online CPUs in those cores. This patch fixes the issue and changes
the behaviour as described, by introducing an arch specific function
topology_is_core_online(). It is currently implemented only for PowerPC.
Fixes: 73c58e7e1412 ("powerpc: Add HOTPLUG_SMT support")
Reported-by: Tyrel Datwyler <[email protected]>
Closes: https://groups.google.com/g/powerpc-utils-devel/c/wrwVzAAnRlI/m/5KJSoqP4BAAJ
Signed-off-by: Nysal Jan K.A <[email protected]>
Reviewed-by: Shrikanth Hegde <[email protected]>
Reviewed-by: Thomas Gleixner <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://msgid.link/[email protected]
Diffstat (limited to 'tools/testing/selftests/bpf/prog_tests/autoload.c')
0 files changed, 0 insertions, 0 deletions