Author: markj Date: Tue Aug 15 16:39:49 2017 New Revision: 322547 URL: https://svnweb.freebsd.org/changeset/base/322547
Log: Add vm_page_alloc_after(). This is a variant of vm_page_alloc() which accepts an additional parameter: the page in the object with largest index that is smaller than the requested index. vm_page_alloc() finds this page using a lookup in the object's radix tree, but in some cases its identity is already known, allowing the lookup to be elided. Modify kmem_back() and vm_page_grab_pages() to use vm_page_alloc_after(). vm_page_alloc() is converted into a trivial wrapper of vm_page_alloc_after(). Suggested by: alc Reviewed by: alc, kib MFC after: 2 weeks Differential Revision: https://reviews.freebsd.org/D11984 Modified: head/sys/vm/vm_kern.c head/sys/vm/vm_page.c head/sys/vm/vm_page.h Modified: head/sys/vm/vm_kern.c ============================================================================== --- head/sys/vm/vm_kern.c Tue Aug 15 15:20:04 2017 (r322546) +++ head/sys/vm/vm_kern.c Tue Aug 15 16:39:49 2017 (r322547) @@ -84,6 +84,7 @@ __FBSDID("$FreeBSD$"); #include <vm/vm_object.h> #include <vm/vm_page.h> #include <vm/vm_pageout.h> +#include <vm/vm_radix.h> #include <vm/vm_extern.h> #include <vm/uma.h> @@ -332,7 +333,7 @@ int kmem_back(vm_object_t object, vm_offset_t addr, vm_size_t size, int flags) { vm_offset_t offset, i; - vm_page_t m; + vm_page_t m, mpred; int pflags; KASSERT(object == kmem_object || object == kernel_object, @@ -341,10 +342,13 @@ kmem_back(vm_object_t object, vm_offset_t addr, vm_siz offset = addr - VM_MIN_KERNEL_ADDRESS; pflags = malloc2vm_flags(flags) | VM_ALLOC_NOBUSY | VM_ALLOC_WIRED; - VM_OBJECT_WLOCK(object); - for (i = 0; i < size; i += PAGE_SIZE) { + i = 0; retry: - m = vm_page_alloc(object, atop(offset + i), pflags); + VM_OBJECT_WLOCK(object); + mpred = vm_radix_lookup_le(&object->rtree, atop(offset + i)); + for (; i < size; i += PAGE_SIZE, mpred = m) { + m = vm_page_alloc_after(object, atop(offset + i), pflags, + mpred); /* * Ran out of space, free everything up and return. Don't need @@ -355,7 +359,6 @@ retry: VM_OBJECT_WUNLOCK(object); if ((flags & M_NOWAIT) == 0) { VM_WAIT; - VM_OBJECT_WLOCK(object); goto retry; } kmem_unback(object, addr, i); Modified: head/sys/vm/vm_page.c ============================================================================== --- head/sys/vm/vm_page.c Tue Aug 15 15:20:04 2017 (r322546) +++ head/sys/vm/vm_page.c Tue Aug 15 16:39:49 2017 (r322547) @@ -1540,15 +1540,32 @@ vm_page_rename(vm_page_t m, vm_object_t new_object, vm vm_page_t vm_page_alloc(vm_object_t object, vm_pindex_t pindex, int req) { - vm_page_t m, mpred; + + return (vm_page_alloc_after(object, pindex, req, object != NULL ? + vm_radix_lookup_le(&object->rtree, pindex) : NULL)); +} + +/* + * Allocate a page in the specified object with the given page index. To + * optimize insertion of the page into the object, the caller must also specifiy + * the resident page in the object with largest index smaller than the given + * page index, or NULL if no such page exists. + */ +vm_page_t +vm_page_alloc_after(vm_object_t object, vm_pindex_t pindex, int req, + vm_page_t mpred) +{ + vm_page_t m; int flags, req_class; - mpred = NULL; /* XXX: pacify gcc */ KASSERT((object != NULL) == ((req & VM_ALLOC_NOOBJ) == 0) && (object != NULL || (req & VM_ALLOC_SBUSY) == 0) && ((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) != (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)), - ("vm_page_alloc: inconsistent object(%p)/req(%x)", object, req)); + ("inconsistent object(%p)/req(%x)", object, req)); + KASSERT(mpred == NULL || mpred->pindex < pindex, + ("mpred %p doesn't precede pindex 0x%jx", mpred, + (uintmax_t)pindex)); if (object != NULL) VM_OBJECT_ASSERT_WLOCKED(object); @@ -1560,12 +1577,6 @@ vm_page_alloc(vm_object_t object, vm_pindex_t pindex, if (curproc == pageproc && req_class != VM_ALLOC_INTERRUPT) req_class = VM_ALLOC_SYSTEM; - if (object != NULL) { - mpred = vm_radix_lookup_le(&object->rtree, pindex); - KASSERT(mpred == NULL || mpred->pindex != pindex, - ("vm_page_alloc: pindex already allocated")); - } - /* * Allocate a page if the number of free pages exceeds the minimum * for the request class. @@ -1612,7 +1623,7 @@ vm_page_alloc(vm_object_t object, vm_pindex_t pindex, /* * At this point we had better have found a good page. */ - KASSERT(m != NULL, ("vm_page_alloc: missing page")); + KASSERT(m != NULL, ("missing page")); vm_phys_freecnt_adj(m, -1); mtx_unlock(&vm_page_queue_free_mtx); vm_page_alloc_check(m); @@ -3185,7 +3196,7 @@ int vm_page_grab_pages(vm_object_t object, vm_pindex_t pindex, int allocflags, vm_page_t *ma, int count) { - vm_page_t m; + vm_page_t m, mpred; int i; bool sleep; @@ -3202,7 +3213,12 @@ vm_page_grab_pages(vm_object_t object, vm_pindex_t pin return (0); i = 0; retrylookup: - m = vm_page_lookup(object, pindex + i); + m = vm_radix_lookup_le(&object->rtree, pindex + i); + if (m == NULL || m->pindex != pindex + i) { + mpred = m; + m = NULL; + } else + mpred = TAILQ_PREV(m, pglist, listq); for (; i < count; i++) { if (m != NULL) { sleep = (allocflags & VM_ALLOC_IGN_SBUSY) != 0 ? @@ -3234,8 +3250,9 @@ retrylookup: if ((allocflags & VM_ALLOC_SBUSY) != 0) vm_page_sbusy(m); } else { - m = vm_page_alloc(object, pindex + i, (allocflags & - ~VM_ALLOC_IGN_SBUSY) | VM_ALLOC_COUNT(count - i)); + m = vm_page_alloc_after(object, pindex + i, + (allocflags & ~VM_ALLOC_IGN_SBUSY) | + VM_ALLOC_COUNT(count - i), mpred); if (m == NULL) { if ((allocflags & VM_ALLOC_NOWAIT) != 0) break; @@ -3250,7 +3267,7 @@ retrylookup: pmap_zero_page(m); m->valid = VM_PAGE_BITS_ALL; } - ma[i] = m; + ma[i] = mpred = m; m = vm_page_next(m); } return (i); Modified: head/sys/vm/vm_page.h ============================================================================== --- head/sys/vm/vm_page.h Tue Aug 15 15:20:04 2017 (r322546) +++ head/sys/vm/vm_page.h Tue Aug 15 16:39:49 2017 (r322547) @@ -464,7 +464,8 @@ void vm_page_free_zero(vm_page_t m); void vm_page_activate (vm_page_t); void vm_page_advise(vm_page_t m, int advice); -vm_page_t vm_page_alloc (vm_object_t, vm_pindex_t, int); +vm_page_t vm_page_alloc(vm_object_t, vm_pindex_t, int); +vm_page_t vm_page_alloc_after(vm_object_t, vm_pindex_t, int, vm_page_t); vm_page_t vm_page_alloc_contig(vm_object_t object, vm_pindex_t pindex, int req, u_long npages, vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary, vm_memattr_t memattr); _______________________________________________ [email protected] mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "[email protected]"
