diff options
| author | Will Deacon <will@kernel.org> | 2021-07-30 14:24:39 +0300 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2021-08-20 13:33:07 +0300 |
| commit | df950811f4a884d08f05e22a8e0089d54bb4ba70 (patch) | |
| tree | 693da5f1837cc38bcb60a4e516fd0ce29df1894b /Documentation/ABI/testing/sysfs-devices-system-cpu | |
| parent | 08cd8f4112dbd33bbfe1112dd6e9f0a228a8e132 (diff) | |
| download | linux-df950811f4a884d08f05e22a8e0089d54bb4ba70.tar.xz | |
arm64: Prevent offlining first CPU with 32-bit EL0 on mismatched system
If we want to support 32-bit applications, then when we identify a CPU
with mismatched 32-bit EL0 support we must ensure that we will always
have an active 32-bit CPU available to us from then on. This is important
for the scheduler, because is_cpu_allowed() will be constrained to 32-bit
CPUs for compat tasks and forced migration due to a hotplug event will
hang if no 32-bit CPUs are available.
On detecting a mismatch, prevent offlining of either the mismatching CPU
if it is 32-bit capable, or find the first active 32-bit capable CPU
otherwise.
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20210730112443.23245-13-will@kernel.org
Diffstat (limited to 'Documentation/ABI/testing/sysfs-devices-system-cpu')
0 files changed, 0 insertions, 0 deletions