mirror of https://github.com/torvalds/linux.git
3be7db6ab4
When an associativity level change is found for one thread, the
siblings threads need to be updated as well. This is done today
for PRRN in stage_topology_update() but is missing for VPHN in
update_cpu_associativity_changes_mask(). This patch will correctly
update all thread siblings during a topology change.
Without this patch a topology update can result in a CPU in
init_sched_groups_power() getting stuck indefinitely in a loop.
This loop is built in build_sched_groups(). As a result of the thread
moving to a node separate from its siblings the struct sched_group will
have its next pointer set to point to itself rather than the sched_group
struct of the next thread. This happens because we have a domain without
the SD_OVERLAP flag, which is correct, and a topology that doesn't conform
with reality (threads on the same core assigned to different numa nodes).
When this list is traversed by init_sched_groups_power() it will reach
the thread's sched_group structure and loop indefinitely; the cpu will
be stuck at this point.
The bug was exposed when VPHN was enabled in commit
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| .. | ||
| 40x_mmu.c | ||
| 44x_mmu.c | ||
| Makefile | ||
| dma-noncoherent.c | ||
| fault.c | ||
| fsl_booke_mmu.c | ||
| gup.c | ||
| hash_low_32.S | ||
| hash_low_64.S | ||
| hash_native_64.c | ||
| hash_utils_64.c | ||
| highmem.c | ||
| hugepage-hash64.c | ||
| hugetlbpage-book3e.c | ||
| hugetlbpage-hash64.c | ||
| hugetlbpage.c | ||
| icswx.c | ||
| icswx.h | ||
| icswx_pid.c | ||
| init_32.c | ||
| init_64.c | ||
| mem.c | ||
| mmap.c | ||
| mmu_context_hash32.c | ||
| mmu_context_hash64.c | ||
| mmu_context_nohash.c | ||
| mmu_decl.h | ||
| numa.c | ||
| pgtable.c | ||
| pgtable_32.c | ||
| pgtable_64.c | ||
| ppc_mmu_32.c | ||
| slb.c | ||
| slb_low.S | ||
| slice.c | ||
| stab.c | ||
| subpage-prot.c | ||
| tlb_hash32.c | ||
| tlb_hash64.c | ||
| tlb_low_64e.S | ||
| tlb_nohash.c | ||
| tlb_nohash_low.S | ||