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author | jchandra <jchandra@FreeBSD.org> | 2010-07-21 09:27:00 +0000 |
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committer | jchandra <jchandra@FreeBSD.org> | 2010-07-21 09:27:00 +0000 |
commit | 10dfd55de4c36ba1bf848c6973ffea562904c58a (patch) | |
tree | 3eec17c60bcda26e4e936937b8f883b4c7a68bb7 /sys/vm/vm_phys.c | |
parent | fbd45b20c30db99fedc41b36dfb0d325d0c2cec3 (diff) | |
download | FreeBSD-src-10dfd55de4c36ba1bf848c6973ffea562904c58a.zip FreeBSD-src-10dfd55de4c36ba1bf848c6973ffea562904c58a.tar.gz |
Redo the page table page allocation on MIPS, as suggested by
alc@.
The UMA zone based allocation is replaced by a scheme that creates
a new free page list for the KSEG0 region, and a new function
in sys/vm that allocates pages from a specific free page list.
This also fixes a race condition introduced by the UMA based page table
page allocation code. Dropping the page queue and pmap locks before
the call to uma_zfree, and re-acquiring them afterwards will introduce
a race condtion(noted by alc@).
The changes are :
- Revert the earlier changes in MIPS pmap.c that added UMA zone for
page table pages.
- Add a new freelist VM_FREELIST_HIGHMEM to MIPS vmparam.h for memory that
is not directly mapped (in 32bit kernel). Normal page allocations will first
try the HIGHMEM freelist and then the default(direct mapped) freelist.
- Add a new function 'vm_page_t vm_page_alloc_freelist(int flind, int
order, int req)' to vm/vm_page.c to allocate a page from a specified
freelist. The MIPS page table pages will be allocated using this function
from the freelist containing direct mapped pages.
- Move the page initialization code from vm_phys_alloc_contig() to a
new function vm_page_alloc_init(), and use this function to initialize
pages in vm_page_alloc_freelist() too.
- Split the function vm_phys_alloc_pages(int pool, int order) to create
vm_phys_alloc_freelist_pages(int flind, int pool, int order), and use
this function from both vm_page_alloc_freelist() and vm_phys_alloc_pages().
Reviewed by: alc
Diffstat (limited to 'sys/vm/vm_phys.c')
-rw-r--r-- | sys/vm/vm_phys.c | 135 |
1 files changed, 61 insertions, 74 deletions
diff --git a/sys/vm/vm_phys.c b/sys/vm/vm_phys.c index a245462..3482337 100644 --- a/sys/vm/vm_phys.c +++ b/sys/vm/vm_phys.c @@ -301,49 +301,67 @@ vm_phys_add_page(vm_paddr_t pa) vm_page_t vm_phys_alloc_pages(int pool, int order) { + vm_page_t m; + int flind; + + for (flind = 0; flind < vm_nfreelists; flind++) { + m = vm_phys_alloc_freelist_pages(flind, pool, order); + if (m != NULL) + return (m); + } + return (NULL); +} + +/* + * Find and dequeue a free page on the given free list, with the + * specified pool and order + */ +vm_page_t +vm_phys_alloc_freelist_pages(int flind, int pool, int order) +{ struct vm_freelist *fl; struct vm_freelist *alt; - int flind, oind, pind; + int oind, pind; vm_page_t m; + KASSERT(flind < VM_NFREELIST, + ("vm_phys_alloc_freelist_pages: freelist %d is out of range", flind)); KASSERT(pool < VM_NFREEPOOL, - ("vm_phys_alloc_pages: pool %d is out of range", pool)); + ("vm_phys_alloc_freelist_pages: pool %d is out of range", pool)); KASSERT(order < VM_NFREEORDER, - ("vm_phys_alloc_pages: order %d is out of range", order)); + ("vm_phys_alloc_freelist_pages: order %d is out of range", order)); mtx_assert(&vm_page_queue_free_mtx, MA_OWNED); - for (flind = 0; flind < vm_nfreelists; flind++) { - fl = vm_phys_free_queues[flind][pool]; - for (oind = order; oind < VM_NFREEORDER; oind++) { - m = TAILQ_FIRST(&fl[oind].pl); + fl = vm_phys_free_queues[flind][pool]; + for (oind = order; oind < VM_NFREEORDER; oind++) { + m = TAILQ_FIRST(&fl[oind].pl); + if (m != NULL) { + TAILQ_REMOVE(&fl[oind].pl, m, pageq); + fl[oind].lcnt--; + m->order = VM_NFREEORDER; + vm_phys_split_pages(m, oind, fl, order); + return (m); + } + } + + /* + * The given pool was empty. Find the largest + * contiguous, power-of-two-sized set of pages in any + * pool. Transfer these pages to the given pool, and + * use them to satisfy the allocation. + */ + for (oind = VM_NFREEORDER - 1; oind >= order; oind--) { + for (pind = 0; pind < VM_NFREEPOOL; pind++) { + alt = vm_phys_free_queues[flind][pind]; + m = TAILQ_FIRST(&alt[oind].pl); if (m != NULL) { - TAILQ_REMOVE(&fl[oind].pl, m, pageq); - fl[oind].lcnt--; + TAILQ_REMOVE(&alt[oind].pl, m, pageq); + alt[oind].lcnt--; m->order = VM_NFREEORDER; + vm_phys_set_pool(pool, m, oind); vm_phys_split_pages(m, oind, fl, order); return (m); } } - - /* - * The given pool was empty. Find the largest - * contiguous, power-of-two-sized set of pages in any - * pool. Transfer these pages to the given pool, and - * use them to satisfy the allocation. - */ - for (oind = VM_NFREEORDER - 1; oind >= order; oind--) { - for (pind = 0; pind < VM_NFREEPOOL; pind++) { - alt = vm_phys_free_queues[flind][pind]; - m = TAILQ_FIRST(&alt[oind].pl); - if (m != NULL) { - TAILQ_REMOVE(&alt[oind].pl, m, pageq); - alt[oind].lcnt--; - m->order = VM_NFREEORDER; - vm_phys_set_pool(pool, m, oind); - vm_phys_split_pages(m, oind, fl, order); - return (m); - } - } - } } return (NULL); } @@ -592,7 +610,7 @@ vm_phys_alloc_contig(unsigned long npages, vm_paddr_t low, vm_paddr_t high, { struct vm_freelist *fl; struct vm_phys_seg *seg; - vm_object_t m_object; + struct vnode *vp; vm_paddr_t pa, pa_last, size; vm_page_t deferred_vdrop_list, m, m_ret; int flind, i, oind, order, pind; @@ -687,50 +705,19 @@ done: vm_phys_split_pages(m_ret, oind, fl, order); for (i = 0; i < npages; i++) { m = &m_ret[i]; - KASSERT(m->queue == PQ_NONE, - ("vm_phys_alloc_contig: page %p has unexpected queue %d", - m, m->queue)); - KASSERT(m->wire_count == 0, - ("vm_phys_alloc_contig: page %p is wired", m)); - KASSERT(m->hold_count == 0, - ("vm_phys_alloc_contig: page %p is held", m)); - KASSERT(m->busy == 0, - ("vm_phys_alloc_contig: page %p is busy", m)); - KASSERT(m->dirty == 0, - ("vm_phys_alloc_contig: page %p is dirty", m)); - KASSERT(pmap_page_get_memattr(m) == VM_MEMATTR_DEFAULT, - ("vm_phys_alloc_contig: page %p has unexpected memattr %d", - m, pmap_page_get_memattr(m))); - if ((m->flags & PG_CACHED) != 0) { - m->valid = 0; - m_object = m->object; - vm_page_cache_remove(m); - if (m_object->type == OBJT_VNODE && - m_object->cache == NULL) { - /* - * Enqueue the vnode for deferred vdrop(). - * - * Unmanaged pages don't use "pageq", so it - * can be safely abused to construct a short- - * lived queue of vnodes. - */ - m->pageq.tqe_prev = m_object->handle; - m->pageq.tqe_next = deferred_vdrop_list; - deferred_vdrop_list = m; - } - } else { - KASSERT(VM_PAGE_IS_FREE(m), - ("vm_phys_alloc_contig: page %p is not free", m)); - KASSERT(m->valid == 0, - ("vm_phys_alloc_contig: free page %p is valid", m)); - cnt.v_free_count--; + vp = vm_page_alloc_init(m); + if (vp != NULL) { + /* + * Enqueue the vnode for deferred vdrop(). + * + * Unmanaged pages don't use "pageq", so it + * can be safely abused to construct a short- + * lived queue of vnodes. + */ + m->pageq.tqe_prev = (void *)vp; + m->pageq.tqe_next = deferred_vdrop_list; + deferred_vdrop_list = m; } - if (m->flags & PG_ZERO) - vm_page_zero_count--; - /* Don't clear the PG_ZERO flag; we'll need it later. */ - m->flags = PG_UNMANAGED | (m->flags & PG_ZERO); - m->oflags = 0; - /* Unmanaged pages don't use "act_count". */ } for (; i < roundup2(npages, 1 << imin(oind, order)); i++) { m = &m_ret[i]; |