diff options
Diffstat (limited to 'pkg/sentry/mm')
| -rw-r--r-- | pkg/sentry/mm/aio_mappable_refs.go | 8 | ||||
| -rw-r--r-- | pkg/sentry/mm/special_mappable_refs.go | 8 |
2 files changed, 16 insertions, 0 deletions
diff --git a/pkg/sentry/mm/aio_mappable_refs.go b/pkg/sentry/mm/aio_mappable_refs.go index 4b87070bf..9bf463256 100644 --- a/pkg/sentry/mm/aio_mappable_refs.go +++ b/pkg/sentry/mm/aio_mappable_refs.go @@ -20,6 +20,14 @@ var aioMappableobj *aioMappable // Refs implements refs.RefCounter. It keeps a reference count using atomic // operations and calls the destructor when the count reaches zero. // +// NOTE: Do not introduce additional fields to the Refs struct. It is used by +// many filesystem objects, and we want to keep it as small as possible (i.e., +// the same size as using an int64 directly) to avoid taking up extra cache +// space. In general, this template should not be extended at the cost of +// performance. If it does not offer enough flexibility for a particular object +// (example: b/187877947), we should implement the RefCounter/CheckedObject +// interfaces manually. +// // +stateify savable type aioMappableRefs struct { // refCount is composed of two fields: diff --git a/pkg/sentry/mm/special_mappable_refs.go b/pkg/sentry/mm/special_mappable_refs.go index 6c89e0f7e..b6d20ede5 100644 --- a/pkg/sentry/mm/special_mappable_refs.go +++ b/pkg/sentry/mm/special_mappable_refs.go @@ -20,6 +20,14 @@ var SpecialMappableobj *SpecialMappable // Refs implements refs.RefCounter. It keeps a reference count using atomic // operations and calls the destructor when the count reaches zero. // +// NOTE: Do not introduce additional fields to the Refs struct. It is used by +// many filesystem objects, and we want to keep it as small as possible (i.e., +// the same size as using an int64 directly) to avoid taking up extra cache +// space. In general, this template should not be extended at the cost of +// performance. If it does not offer enough flexibility for a particular object +// (example: b/187877947), we should implement the RefCounter/CheckedObject +// interfaces manually. +// // +stateify savable type SpecialMappableRefs struct { // refCount is composed of two fields: |