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| author |   James Morse <james.morse@arm.com> | 2016-06-22 10:06:12 +0100 |
|---|---|---|
| committer |   Will Deacon <will.deacon@arm.com> | 2016-06-22 15:48:09 +0100 |
| commit | 5c492c3f5255bd34f7ff8867515ecf98dcba2a2e (patch) | |
| tree | eea6ba5d5f8b8ef37f6218bda83c03e081d95e9d /scripts/gdb/linux/utils.py | |
| parent | arm64: mm: remove page_mapping check in __sync_icache_dcache (diff) | |
| download | linux-rng-5c492c3f5255bd34f7ff8867515ecf98dcba2a2e.tar.xz linux-rng-5c492c3f5255bd34f7ff8867515ecf98dcba2a2e.zip | |
arm64: smp: Add function to determine if cpus are stuck in the kernel
kernel/smp.c has a fancy counter that keeps track of the number of CPUs
it marked as not-present and left in cpu_park_loop(). If there are any
CPUs spinning in here, features like kexec or hibernate may release them
by overwriting this memory.
This problem also occurs on machines using spin-tables to release
secondary cores.
After commit 44dbcc93ab67 ("arm64: Fix behavior of maxcpus=N")
we bring all known cpus into the secondary holding pen, meaning this
memory can't be re-used by kexec or hibernate.
Add a function cpus_are_stuck_in_kernel() to determine if either of these
cases have occurred.
Signed-off-by: James Morse <james.morse@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'scripts/gdb/linux/utils.py')
0 files changed, 0 insertions, 0 deletions