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| author | Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> | 2019-10-24 12:35:42 +0300 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2019-10-28 13:54:16 +0300 |
| commit | d78d5dace5398b542fd5a21b50db6e88ce7d392e (patch) | |
| tree | 5535b8a1804be8acac2d2af6547ae031ff728a7f /arch/powerpc/mm/book3s64/hash_utils.c | |
| parent | 75838a3290cd4ebbd1f567f310ba04b6ef017ce4 (diff) | |
| download | linux-d78d5dace5398b542fd5a21b50db6e88ce7d392e.tar.xz | |
powerpc/book3s64/hash: Use secondary hash for bolted mapping if the primary is full
With bolted hash page table entry, kernel currently only use primary hash group
when inserting the hash page table entry. In the rare case where kernel find all the
8 primary hash slot occupied by bolted entries, this can result in hash page
table insert failure for bolted entries. Avoid this by using the secondary hash
group.
This is different from what kernel does for the non-bolted mapping. With
non-bolted entries kernel will try secondary before removing an existing entry
from hash page table group. With bolted prefer primary hash group and hence
try to insert the page table entry by removing a slot from primary before trying
the secondary hash group.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191024093542.29777-3-aneesh.kumar@linux.ibm.com
Diffstat (limited to 'arch/powerpc/mm/book3s64/hash_utils.c')
| -rw-r--r-- | arch/powerpc/mm/book3s64/hash_utils.c | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/arch/powerpc/mm/book3s64/hash_utils.c b/arch/powerpc/mm/book3s64/hash_utils.c index 6e5a769ebcb8..a9d1f72de848 100644 --- a/arch/powerpc/mm/book3s64/hash_utils.c +++ b/arch/powerpc/mm/book3s64/hash_utils.c @@ -263,6 +263,7 @@ int htab_bolt_mapping(unsigned long vstart, unsigned long vend, unsigned long vsid = get_kernel_vsid(vaddr, ssize); unsigned long vpn = hpt_vpn(vaddr, vsid, ssize); unsigned long tprot = prot; + bool secondary_hash = false; /* * If we hit a bad address return error. @@ -291,17 +292,27 @@ int htab_bolt_mapping(unsigned long vstart, unsigned long vend, hpteg = ((hash & htab_hash_mask) * HPTES_PER_GROUP); BUG_ON(!mmu_hash_ops.hpte_insert); +repeat: ret = mmu_hash_ops.hpte_insert(hpteg, vpn, paddr, tprot, HPTE_V_BOLTED, psize, psize, ssize); if (ret == -1) { - /* Try to remove a non bolted entry */ + /* + * Try to to keep bolted entries in primary. + * Remove non bolted entries and try insert again + */ ret = mmu_hash_ops.hpte_remove(hpteg); if (ret != -1) ret = mmu_hash_ops.hpte_insert(hpteg, vpn, paddr, tprot, HPTE_V_BOLTED, psize, psize, ssize); + if (ret == -1 && !secondary_hash) { + secondary_hash = true; + hpteg = ((~hash & htab_hash_mask) * HPTES_PER_GROUP); + goto repeat; + } } + if (ret < 0) break; |