Author: markj Date: Wed Jun 26 17:37:51 2019 New Revision: 349432 URL: https://svnweb.freebsd.org/changeset/base/349432
Log: Add a return value to vm_page_remove(). Use it to indicate whether the page may be safely freed following its removal from the object. Also change vm_page_remove() to assume that the page's object pointer is non-NULL, and have callers perform this check instead. This is a step towards an implementation of an atomic reference counter for each physical page structure. Reviewed by: alc, dougm, kib MFC after: 1 week Sponsored by: Netflix Differential Revision: https://reviews.freebsd.org/D20758 Modified: head/sys/amd64/sgx/sgx.c head/sys/dev/drm2/ttm/ttm_bo_vm.c head/sys/vm/device_pager.c head/sys/vm/vm_fault.c head/sys/vm/vm_object.c head/sys/vm/vm_page.c head/sys/vm/vm_page.h Modified: head/sys/amd64/sgx/sgx.c ============================================================================== --- head/sys/amd64/sgx/sgx.c Wed Jun 26 17:32:31 2019 (r349431) +++ head/sys/amd64/sgx/sgx.c Wed Jun 26 17:37:51 2019 (r349432) @@ -358,7 +358,7 @@ sgx_page_remove(struct sgx_softc *sc, vm_page_t p) uint64_t offs; vm_page_lock(p); - vm_page_remove(p); + (void)vm_page_remove(p); vm_page_unlock(p); dprintf("%s: p->pidx %ld\n", __func__, p->pindex); Modified: head/sys/dev/drm2/ttm/ttm_bo_vm.c ============================================================================== --- head/sys/dev/drm2/ttm/ttm_bo_vm.c Wed Jun 26 17:32:31 2019 (r349431) +++ head/sys/dev/drm2/ttm/ttm_bo_vm.c Wed Jun 26 17:37:51 2019 (r349432) @@ -115,7 +115,7 @@ ttm_bo_vm_fault(vm_object_t vm_obj, vm_ooffset_t offse vm_object_pip_add(vm_obj, 1); if (*mres != NULL) { vm_page_lock(*mres); - vm_page_remove(*mres); + (void)vm_page_remove(*mres); vm_page_unlock(*mres); } retry: Modified: head/sys/vm/device_pager.c ============================================================================== --- head/sys/vm/device_pager.c Wed Jun 26 17:32:31 2019 (r349431) +++ head/sys/vm/device_pager.c Wed Jun 26 17:37:51 2019 (r349432) @@ -236,7 +236,7 @@ cdev_pager_free_page(vm_object_t object, vm_page_t m) KASSERT((m->oflags & VPO_UNMANAGED) == 0, ("unmanaged %p", m)); pmap_remove_all(m); vm_page_lock(m); - vm_page_remove(m); + (void)vm_page_remove(m); vm_page_unlock(m); } else if (object->type == OBJT_DEVICE) dev_pager_free_page(object, m); Modified: head/sys/vm/vm_fault.c ============================================================================== --- head/sys/vm/vm_fault.c Wed Jun 26 17:32:31 2019 (r349431) +++ head/sys/vm/vm_fault.c Wed Jun 26 17:37:51 2019 (r349432) @@ -1144,7 +1144,7 @@ readrest: fs.object == fs.first_object->backing_object) { vm_page_lock(fs.m); vm_page_dequeue(fs.m); - vm_page_remove(fs.m); + (void)vm_page_remove(fs.m); vm_page_unlock(fs.m); vm_page_lock(fs.first_m); vm_page_replace_checked(fs.m, fs.first_object, Modified: head/sys/vm/vm_object.c ============================================================================== --- head/sys/vm/vm_object.c Wed Jun 26 17:32:31 2019 (r349431) +++ head/sys/vm/vm_object.c Wed Jun 26 17:37:51 2019 (r349432) @@ -1595,10 +1595,8 @@ vm_object_collapse_scan(vm_object_t object, int op) vm_page_lock(p); KASSERT(!pmap_page_is_mapped(p), ("freeing mapped page %p", p)); - if (!vm_page_wired(p)) + if (vm_page_remove(p)) vm_page_free(p); - else - vm_page_remove(p); vm_page_unlock(p); continue; } @@ -1639,10 +1637,8 @@ vm_object_collapse_scan(vm_object_t object, int op) vm_page_lock(p); KASSERT(!pmap_page_is_mapped(p), ("freeing mapped page %p", p)); - if (!vm_page_wired(p)) + if (vm_page_remove(p)) vm_page_free(p); - else - vm_page_remove(p); vm_page_unlock(p); continue; } Modified: head/sys/vm/vm_page.c ============================================================================== --- head/sys/vm/vm_page.c Wed Jun 26 17:32:31 2019 (r349431) +++ head/sys/vm/vm_page.c Wed Jun 26 17:37:51 2019 (r349432) @@ -1458,20 +1458,21 @@ vm_page_insert_radixdone(vm_page_t m, vm_object_t obje * vm_page_remove: * * Removes the specified page from its containing object, but does not - * invalidate any backing storage. + * invalidate any backing storage. Return true if the page may be safely + * freed and false otherwise. * * The object must be locked. The page must be locked if it is managed. */ -void +bool vm_page_remove(vm_page_t m) { vm_object_t object; vm_page_t mrem; + object = m->object; + if ((m->oflags & VPO_UNMANAGED) == 0) vm_page_assert_locked(m); - if ((object = m->object) == NULL) - return; VM_OBJECT_ASSERT_WLOCKED(object); if (vm_page_xbusied(m)) vm_page_xunbusy_maybelocked(m); @@ -1495,6 +1496,7 @@ vm_page_remove(vm_page_t m) vdrop(object->handle); m->object = NULL; + return (!vm_page_wired(m)); } /* @@ -1665,7 +1667,7 @@ vm_page_rename(vm_page_t m, vm_object_t new_object, vm */ m->pindex = opidx; vm_page_lock(m); - vm_page_remove(m); + (void)vm_page_remove(m); /* Return back to the new pindex to complete vm_page_insert(). */ m->pindex = new_pindex; @@ -3436,7 +3438,8 @@ vm_page_free_prep(vm_page_t m) if (vm_page_sbusied(m)) panic("vm_page_free_prep: freeing busy page %p", m); - vm_page_remove(m); + if (m->object != NULL) + (void)vm_page_remove(m); /* * If fictitious remove object association and Modified: head/sys/vm/vm_page.h ============================================================================== --- head/sys/vm/vm_page.h Wed Jun 26 17:32:31 2019 (r349431) +++ head/sys/vm/vm_page.h Wed Jun 26 17:37:51 2019 (r349432) @@ -561,7 +561,7 @@ bool vm_page_reclaim_contig(int req, u_long npages, vm bool vm_page_reclaim_contig_domain(int domain, int req, u_long npages, vm_paddr_t low, vm_paddr_t high, u_long alignment, vm_paddr_t boundary); void vm_page_reference(vm_page_t m); -void vm_page_remove (vm_page_t); +bool vm_page_remove(vm_page_t); int vm_page_rename (vm_page_t, vm_object_t, vm_pindex_t); vm_page_t vm_page_replace(vm_page_t mnew, vm_object_t object, vm_pindex_t pindex); _______________________________________________ svn-src-all@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
