svn commit: r269433 - head/sys/vm
Alan Cox
alc at rice.edu
Sat Aug 2 17:03:56 UTC 2014
On 08/02/2014 11:54, Bjoern A. Zeeb wrote:
> On 02 Aug 2014, at 16:10 , Alan Cox <alc at FreeBSD.org> wrote:
>
>> Author: alc
>> Date: Sat Aug 2 16:10:24 2014
>> New Revision: 269433
>> URL: http://svnweb.freebsd.org/changeset/base/269433
>>
>> Log:
>> Handle wiring failures in vm_map_wire() with the new functions
>> pmap_unwire() and vm_object_unwire().
>>
>> Retire vm_fault_{un,}wire(), since they are no longer used.
>>
>> (See r268327 and r269134 for the motivation behind this change.)
>>
>> Reviewed by: kib
>> Sponsored by: EMC / Isilon Storage Division
>>
> cc1: warnings being treated as errors
> /scratch/tmp/bz/head.svn/sys/vm/vm_map.c: In function 'vm_map_wire':
> /scratch/tmp/bz/head.svn/sys/vm/vm_map.c:2470: warning: 'rv' may be used uninitialized in this function
> --- vm_map.o ---
> *** [vm_map.o] Error code 1
gcc?
>
>
>> Modified:
>> head/sys/vm/vm_extern.h
>> head/sys/vm/vm_fault.c
>> head/sys/vm/vm_map.c
>>
>> Modified: head/sys/vm/vm_extern.h
>> ==============================================================================
>> --- head/sys/vm/vm_extern.h Sat Aug 2 15:05:23 2014 (r269432)
>> +++ head/sys/vm/vm_extern.h Sat Aug 2 16:10:24 2014 (r269433)
>> @@ -81,7 +81,6 @@ int vm_fault_hold(vm_map_t map, vm_offse
>> int fault_flags, vm_page_t *m_hold);
>> int vm_fault_quick_hold_pages(vm_map_t map, vm_offset_t addr, vm_size_t len,
>> vm_prot_t prot, vm_page_t *ma, int max_count);
>> -int vm_fault_wire(vm_map_t, vm_offset_t, vm_offset_t, boolean_t);
>> int vm_forkproc(struct thread *, struct proc *, struct thread *, struct vmspace *, int);
>> void vm_waitproc(struct proc *);
>> int vm_mmap(vm_map_t, vm_offset_t *, vm_size_t, vm_prot_t, vm_prot_t, int, objtype_t, void *, vm_ooffset_t);
>>
>> Modified: head/sys/vm/vm_fault.c
>> ==============================================================================
>> --- head/sys/vm/vm_fault.c Sat Aug 2 15:05:23 2014 (r269432)
>> +++ head/sys/vm/vm_fault.c Sat Aug 2 16:10:24 2014 (r269433)
>> @@ -106,7 +106,6 @@ __FBSDID("$FreeBSD$");
>> #define PFFOR 4
>>
>> static int vm_fault_additional_pages(vm_page_t, int, int, vm_page_t *, int *);
>> -static void vm_fault_unwire(vm_map_t, vm_offset_t, vm_offset_t, boolean_t);
>>
>> #define VM_FAULT_READ_BEHIND 8
>> #define VM_FAULT_READ_MAX (1 + VM_FAULT_READ_AHEAD_MAX)
>> @@ -1155,68 +1154,6 @@ error:
>> }
>>
>> /*
>> - * vm_fault_wire:
>> - *
>> - * Wire down a range of virtual addresses in a map.
>> - */
>> -int
>> -vm_fault_wire(vm_map_t map, vm_offset_t start, vm_offset_t end,
>> - boolean_t fictitious)
>> -{
>> - vm_offset_t va;
>> - int rv;
>> -
>> - /*
>> - * We simulate a fault to get the page and enter it in the physical
>> - * map. For user wiring, we only ask for read access on currently
>> - * read-only sections.
>> - */
>> - for (va = start; va < end; va += PAGE_SIZE) {
>> - rv = vm_fault(map, va, VM_PROT_NONE, VM_FAULT_CHANGE_WIRING);
>> - if (rv) {
>> - if (va != start)
>> - vm_fault_unwire(map, start, va, fictitious);
>> - return (rv);
>> - }
>> - }
>> - return (KERN_SUCCESS);
>> -}
>> -
>> -/*
>> - * vm_fault_unwire:
>> - *
>> - * Unwire a range of virtual addresses in a map.
>> - */
>> -static void
>> -vm_fault_unwire(vm_map_t map, vm_offset_t start, vm_offset_t end,
>> - boolean_t fictitious)
>> -{
>> - vm_paddr_t pa;
>> - vm_offset_t va;
>> - vm_page_t m;
>> - pmap_t pmap;
>> -
>> - pmap = vm_map_pmap(map);
>> -
>> - /*
>> - * Since the pages are wired down, we must be able to get their
>> - * mappings from the physical map system.
>> - */
>> - for (va = start; va < end; va += PAGE_SIZE) {
>> - pa = pmap_extract(pmap, va);
>> - if (pa != 0) {
>> - pmap_change_wiring(pmap, va, FALSE);
>> - if (!fictitious) {
>> - m = PHYS_TO_VM_PAGE(pa);
>> - vm_page_lock(m);
>> - vm_page_unwire(m, PQ_ACTIVE);
>> - vm_page_unlock(m);
>> - }
>> - }
>> - }
>> -}
>> -
>> -/*
>> * Routine:
>> * vm_fault_copy_entry
>> * Function:
>>
>> Modified: head/sys/vm/vm_map.c
>> ==============================================================================
>> --- head/sys/vm/vm_map.c Sat Aug 2 15:05:23 2014 (r269432)
>> +++ head/sys/vm/vm_map.c Sat Aug 2 16:10:24 2014 (r269433)
>> @@ -140,6 +140,8 @@ static void vmspace_zdtor(void *mem, int
>> static int vm_map_stack_locked(vm_map_t map, vm_offset_t addrbos,
>> vm_size_t max_ssize, vm_size_t growsize, vm_prot_t prot, vm_prot_t max,
>> int cow);
>> +static void vm_map_wire_entry_failure(vm_map_t map, vm_map_entry_t entry,
>> + vm_offset_t failed_addr);
>>
>> #define ENTRY_CHARGED(e) ((e)->cred != NULL || \
>> ((e)->object.vm_object != NULL && (e)->object.vm_object->cred != NULL && \
>> @@ -2418,6 +2420,42 @@ done:
>> }
>>
>> /*
>> + * vm_map_wire_entry_failure:
>> + *
>> + * Handle a wiring failure on the given entry.
>> + *
>> + * The map should be locked.
>> + */
>> +static void
>> +vm_map_wire_entry_failure(vm_map_t map, vm_map_entry_t entry,
>> + vm_offset_t failed_addr)
>> +{
>> +
>> + VM_MAP_ASSERT_LOCKED(map);
>> + KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0 &&
>> + entry->wired_count == 1,
>> + ("vm_map_wire_entry_failure: entry %p isn't being wired", entry));
>> + KASSERT(failed_addr < entry->end,
>> + ("vm_map_wire_entry_failure: entry %p was fully wired", entry));
>> +
>> + /*
>> + * If any pages at the start of this entry were successfully wired,
>> + * then unwire them.
>> + */
>> + if (failed_addr > entry->start) {
>> + pmap_unwire(map->pmap, entry->start, failed_addr);
>> + vm_object_unwire(entry->object.vm_object, entry->offset,
>> + failed_addr - entry->start, PQ_ACTIVE);
>> + }
>> +
>> + /*
>> + * Assign an out-of-range value to represent the failure to wire this
>> + * entry.
>> + */
>> + entry->wired_count = -1;
>> +}
>> +
>> +/*
>> * vm_map_wire:
>> *
>> * Implements both kernel and user wiring.
>> @@ -2427,10 +2465,10 @@ vm_map_wire(vm_map_t map, vm_offset_t st
>> int flags)
>> {
>> vm_map_entry_t entry, first_entry, tmp_entry;
>> - vm_offset_t saved_end, saved_start;
>> + vm_offset_t faddr, saved_end, saved_start;
>> unsigned int last_timestamp;
>> int rv;
>> - boolean_t fictitious, need_wakeup, result, user_wire;
>> + boolean_t need_wakeup, result, user_wire;
>> vm_prot_t prot;
>>
>> if (start == end)
>> @@ -2523,17 +2561,24 @@ vm_map_wire(vm_map_t map, vm_offset_t st
>> entry->wired_count++;
>> saved_start = entry->start;
>> saved_end = entry->end;
>> - fictitious = entry->object.vm_object != NULL &&
>> - (entry->object.vm_object->flags &
>> - OBJ_FICTITIOUS) != 0;
>> +
>> /*
>> * Release the map lock, relying on the in-transition
>> * mark. Mark the map busy for fork.
>> */
>> vm_map_busy(map);
>> vm_map_unlock(map);
>> - rv = vm_fault_wire(map, saved_start, saved_end,
>> - fictitious);
>> +
>> + for (faddr = saved_start; faddr < saved_end; faddr +=
>> + PAGE_SIZE) {
>> + /*
>> + * Simulate a fault to get the page and enter
>> + * it into the physical map.
>> + */
>> + if ((rv = vm_fault(map, faddr, VM_PROT_NONE,
>> + VM_FAULT_CHANGE_WIRING)) != KERN_SUCCESS)
>> + break;
>> + }
>> vm_map_lock(map);
>> vm_map_unbusy(map);
>> if (last_timestamp + 1 != map->timestamp) {
>> @@ -2552,23 +2597,22 @@ vm_map_wire(vm_map_t map, vm_offset_t st
>> first_entry = NULL;
>> entry = tmp_entry;
>> while (entry->end < saved_end) {
>> - if (rv != KERN_SUCCESS) {
>> - KASSERT(entry->wired_count == 1,
>> - ("vm_map_wire: bad count"));
>> - entry->wired_count = -1;
>> - }
>> + /*
>> + * In case of failure, handle entries
>> + * that were not fully wired here;
>> + * fully wired entries are handled
>> + * later.
>> + */
>> + if (rv != KERN_SUCCESS &&
>> + faddr < entry->end)
>> + vm_map_wire_entry_failure(map,
>> + entry, faddr);
>> entry = entry->next;
>> }
>> }
>> last_timestamp = map->timestamp;
>> if (rv != KERN_SUCCESS) {
>> - KASSERT(entry->wired_count == 1,
>> - ("vm_map_wire: bad count"));
>> - /*
>> - * Assign an out-of-range value to represent
>> - * the failure to wire this entry.
>> - */
>> - entry->wired_count = -1;
>> + vm_map_wire_entry_failure(map, entry, faddr);
>> end = entry->end;
>> goto done;
>> }
>> @@ -2632,6 +2676,10 @@ done:
>> entry->wired_count = 0;
>> } else if (!user_wire ||
>> (entry->eflags & MAP_ENTRY_USER_WIRED) == 0) {
>> + /*
>> + * Undo the wiring. Wiring succeeded on this entry
>> + * but failed on a later entry.
>> + */
>> if (entry->wired_count == 1)
>> vm_map_entry_unwire(map, entry);
>> else
>>
> —
> Bjoern A. Zeeb "Come on. Learn, goddamn it.", WarGames, 1983
>
>
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