diff options
| -rw-r--r-- | sys/vm/vm_reserv.c | 32 |
1 files changed, 23 insertions, 9 deletions
diff --git a/sys/vm/vm_reserv.c b/sys/vm/vm_reserv.c index 7511a33..d83b3ce 100644 --- a/sys/vm/vm_reserv.c +++ b/sys/vm/vm_reserv.c @@ -299,7 +299,7 @@ vm_reserv_populate(vm_reserv_t rv) /* * Allocates a contiguous set of physical pages of the given size "npages" - * from an existing or newly-created reservation. All of the physical pages + * from existing or newly created reservations. All of the physical pages * must be at or above the given physical address "low" and below the given * physical address "high". The given value "alignment" determines the * alignment of the first physical page in the set. If the given value @@ -371,8 +371,8 @@ vm_reserv_alloc_contig(vm_object_t object, vm_pindex_t pindex, u_long npages, /* * Could at least one reservation fit between the first index to the - * left that can be used and the first index to the right that cannot - * be used? + * left that can be used ("leftcap") and the first index to the right + * that cannot be used ("rightcap")? */ first = pindex - VM_RESERV_INDEX(object, pindex); if (mpred != NULL) { @@ -394,6 +394,13 @@ vm_reserv_alloc_contig(vm_object_t object, vm_pindex_t pindex, u_long npages, if (first + maxpages > rightcap) { if (maxpages == VM_LEVEL_0_NPAGES) return (NULL); + + /* + * At least one reservation will fit between "leftcap" + * and "rightcap". However, a reservation for the + * last of the requested pages will not fit. Reduce + * the size of the upcoming allocation accordingly. + */ allocpages = minpages; } } @@ -417,16 +424,23 @@ vm_reserv_alloc_contig(vm_object_t object, vm_pindex_t pindex, u_long npages, } /* - * Allocate and populate the new reservations. The alignment and - * boundary specified for this allocation may be different from the - * alignment and boundary specified for the requested pages. For - * instance, the specified index may not be the first page within the - * first new reservation. + * Allocate the physical pages. The alignment and boundary specified + * for this allocation may be different from the alignment and + * boundary specified for the requested pages. For instance, the + * specified index may not be the first page within the first new + * reservation. */ m = vm_phys_alloc_contig(allocpages, low, high, ulmax(alignment, VM_LEVEL_0_SIZE), boundary > VM_LEVEL_0_SIZE ? boundary : 0); if (m == NULL) return (NULL); + + /* + * The allocated physical pages always begin at a reservation + * boundary, but they do not always end at a reservation boundary. + * Initialize every reservation that is completely covered by the + * allocated physical pages. + */ m_ret = NULL; index = VM_RESERV_INDEX(object, pindex); do { @@ -456,7 +470,7 @@ vm_reserv_alloc_contig(vm_object_t object, vm_pindex_t pindex, u_long npages, m += VM_LEVEL_0_NPAGES; first += VM_LEVEL_0_NPAGES; allocpages -= VM_LEVEL_0_NPAGES; - } while (allocpages > 0); + } while (allocpages >= VM_LEVEL_0_NPAGES); return (m_ret); /* |
