Applied, thanks!
Sergey Bugaev, le lun. 26 juin 2023 14:26:53 +0300, a ecrit:
> When entering an object into a map, try to extend the next entry
> backward, in addition to the previously existing attempt to extend the
> previous entry forward.
> ---
> vm/vm_map.c | 39 +++++++++++++++++++++++++++++++++++----
> 1 file changed, 35 insertions(+), 4 deletions(-)
>
> diff --git a/vm/vm_map.c b/vm/vm_map.c
> index a41e6434..0d3b11f2 100644
> --- a/vm/vm_map.c
> +++ b/vm/vm_map.c
> @@ -992,6 +992,7 @@ kern_return_t vm_map_enter(
> vm_inherit_t inheritance)
> {
> vm_map_entry_t entry;
> + vm_map_entry_t next_entry;
> vm_offset_t start;
> vm_offset_t end;
> kern_return_t result = KERN_SUCCESS;
> @@ -1012,6 +1013,7 @@ kern_return_t vm_map_enter(
>
> end = start + size;
> *address = start;
> + next_entry = entry->vme_next;
> } else {
> vm_map_entry_t temp_entry;
>
> @@ -1046,14 +1048,15 @@ kern_return_t vm_map_enter(
> RETURN(KERN_NO_SPACE);
>
> entry = temp_entry;
> + next_entry = entry->vme_next;
>
> /*
> * ... the next region doesn't overlap the
> * end point.
> */
>
> - if ((entry->vme_next != vm_map_to_entry(map)) &&
> - (entry->vme_next->vme_start < end))
> + if ((next_entry != vm_map_to_entry(map)) &&
> + (next_entry->vme_start < end))
> RETURN(KERN_NO_SPACE);
> }
>
> @@ -1069,8 +1072,7 @@ kern_return_t vm_map_enter(
>
> /*
> * See whether we can avoid creating a new entry (and object) by
> - * extending one of our neighbors. [So far, we only attempt to
> - * extend from below.]
> + * extending one of our neighbors.
> */
>
> if ((entry != vm_map_to_entry(map)) &&
> @@ -1101,6 +1103,35 @@ kern_return_t vm_map_enter(
> RETURN(KERN_SUCCESS);
> }
> }
> + if ((next_entry != vm_map_to_entry(map)) &&
> + (next_entry->vme_start == end) &&
> + (!next_entry->is_shared) &&
> + (!next_entry->is_sub_map) &&
> + (next_entry->inheritance == inheritance) &&
> + (next_entry->protection == cur_protection) &&
> + (next_entry->max_protection == max_protection) &&
> + (next_entry->wired_count == 0) &&
> + (next_entry->projected_on == 0)) {
> + if (vm_object_coalesce(object,
> + next_entry->object.vm_object,
> + offset,
> + next_entry->offset,
> + size,
> + (vm_size_t)(next_entry->vme_end -
> next_entry->vme_start))) {
> +
> + /*
> + * Coalesced the two objects - can extend
> + * the next map entry to include the
> + * new range.
> + */
> + map->size += size;
> + next_entry->vme_start = start;
> + next_entry->offset -= size;
> + vm_map_gap_update(&map->hdr, entry);
> + vm_object_deallocate(object);
> + RETURN(KERN_SUCCESS);
> + }
> + }
>
> /*
> * Create a new entry
> --
> 2.41.0
>
--
Samuel
---
Pour une évaluation indépendante, transparente et rigoureuse !
Je soutiens la Commission d'Évaluation de l'Inria.
