diff options
| author | Quentin Perret <qperret@google.com> | 2021-06-08 14:45:18 +0300 |
|---|---|---|
| committer | Marc Zyngier <maz@kernel.org> | 2021-06-11 15:24:12 +0300 |
| commit | 6929586d8eddad184f43526efe7bf0a8be4f18b2 (patch) | |
| tree | 285136df8a757c3ade2eaa347c1386c0a5fa9009 | |
| parent | 87ec0606733e1aa9568f54ddb41f03aa6b5687f2 (diff) | |
| download | linux-6929586d8eddad184f43526efe7bf0a8be4f18b2.tar.xz | |
KVM: arm64: Use less bits for hyp_page refcount
The hyp_page refcount is currently encoded on 4 bytes even though we
never need to count that many objects in a page. Make it 2 bytes to save
some space in the vmemmap.
As overflows are more likely to happen as well, make sure to catch those
with a BUG in the increment function.
Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210608114518.748712-8-qperret@google.com
| -rw-r--r-- | arch/arm64/kvm/hyp/include/nvhe/memory.h | 2 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/nvhe/page_alloc.c | 1 |
2 files changed, 2 insertions, 1 deletions
diff --git a/arch/arm64/kvm/hyp/include/nvhe/memory.h b/arch/arm64/kvm/hyp/include/nvhe/memory.h index 3fe34fa30ea4..592b7edb3edb 100644 --- a/arch/arm64/kvm/hyp/include/nvhe/memory.h +++ b/arch/arm64/kvm/hyp/include/nvhe/memory.h @@ -8,7 +8,7 @@ #include <linux/types.h> struct hyp_page { - unsigned int refcount; + unsigned short refcount; unsigned short order; }; diff --git a/arch/arm64/kvm/hyp/nvhe/page_alloc.c b/arch/arm64/kvm/hyp/nvhe/page_alloc.c index be07055bbc10..41fc25bdfb34 100644 --- a/arch/arm64/kvm/hyp/nvhe/page_alloc.c +++ b/arch/arm64/kvm/hyp/nvhe/page_alloc.c @@ -146,6 +146,7 @@ static struct hyp_page *__hyp_extract_page(struct hyp_pool *pool, static inline void hyp_page_ref_inc(struct hyp_page *p) { + BUG_ON(p->refcount == USHRT_MAX); p->refcount++; } |