Date: Mon, 3 Jun 2019 05:15:36 +0000 (UTC) From: Alan Cox <alc@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r348525 - head/sys/vm Message-ID: <201906030515.x535Fa4c049045@repo.freebsd.org>
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Author: alc Date: Mon Jun 3 05:15:36 2019 New Revision: 348525 URL: https://svnweb.freebsd.org/changeset/base/348525 Log: Retire vm_reserv_extend_{contig,page}(). These functions were introduced as part of a false start toward fine-grained reservation locking. In the end, they were not needed, so eliminate them. Order the parameters to vm_reserv_alloc_{contig,page}() consistently with the vm_page functions that call them. Update the comments about the locking requirements for vm_reserv_alloc_{contig,page}(). They no longer require a free page queues lock. Wrap several lines that became too long after the "req" and "domain" parameters were added to vm_reserv_alloc_{contig,page}(). Reviewed by: kib, markj MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D20492 Modified: head/sys/vm/vm_page.c head/sys/vm/vm_reserv.c head/sys/vm/vm_reserv.h Modified: head/sys/vm/vm_page.c ============================================================================== --- head/sys/vm/vm_page.c Mon Jun 3 04:38:07 2019 (r348524) +++ head/sys/vm/vm_page.c Mon Jun 3 05:15:36 2019 (r348525) @@ -1834,8 +1834,8 @@ again: * Can we allocate the page from a reservation? */ if (vm_object_reserv(object) && - ((m = vm_reserv_extend(req, object, pindex, domain, mpred)) != NULL || - (m = vm_reserv_alloc_page(req, object, pindex, domain, mpred)) != NULL)) { + (m = vm_reserv_alloc_page(object, pindex, domain, req, mpred)) != + NULL) { domain = vm_phys_domain(m); vmd = VM_DOMAIN(domain); goto found; @@ -2039,10 +2039,8 @@ again: * Can we allocate the pages from a reservation? */ if (vm_object_reserv(object) && - ((m_ret = vm_reserv_extend_contig(req, object, pindex, domain, - npages, low, high, alignment, boundary, mpred)) != NULL || - (m_ret = vm_reserv_alloc_contig(req, object, pindex, domain, - npages, low, high, alignment, boundary, mpred)) != NULL)) { + (m_ret = vm_reserv_alloc_contig(object, pindex, domain, req, + mpred, npages, low, high, alignment, boundary)) != NULL) { domain = vm_phys_domain(m_ret); vmd = VM_DOMAIN(domain); goto found; Modified: head/sys/vm/vm_reserv.c ============================================================================== --- head/sys/vm/vm_reserv.c Mon Jun 3 04:38:07 2019 (r348524) +++ head/sys/vm/vm_reserv.c Mon Jun 3 05:15:36 2019 (r348525) @@ -576,95 +576,8 @@ vm_reserv_populate(vm_reserv_t rv, int index) } /* - * Attempts to allocate a contiguous set of physical pages from existing - * reservations. See vm_reserv_alloc_contig() for a description of the - * function's parameters. - * - * The page "mpred" must immediately precede the offset "pindex" within the - * specified object. - * - * The object must be locked. - */ -vm_page_t -vm_reserv_extend_contig(int req, vm_object_t object, vm_pindex_t pindex, - int domain, u_long npages, vm_paddr_t low, vm_paddr_t high, - u_long alignment, vm_paddr_t boundary, vm_page_t mpred) -{ - struct vm_domain *vmd; - vm_paddr_t pa, size; - vm_page_t m, msucc; - vm_reserv_t rv; - int i, index; - - VM_OBJECT_ASSERT_WLOCKED(object); - KASSERT(npages != 0, ("vm_reserv_alloc_contig: npages is 0")); - - /* - * Is a reservation fundamentally impossible? - */ - if (pindex < VM_RESERV_INDEX(object, pindex) || - pindex + npages > object->size || object->resident_page_count == 0) - return (NULL); - - /* - * All reservations of a particular size have the same alignment. - * Assuming that the first page is allocated from a reservation, the - * least significant bits of its physical address can be determined - * from its offset from the beginning of the reservation and the size - * of the reservation. - * - * Could the specified index within a reservation of the smallest - * possible size satisfy the alignment and boundary requirements? - */ - pa = VM_RESERV_INDEX(object, pindex) << PAGE_SHIFT; - if ((pa & (alignment - 1)) != 0) - return (NULL); - size = npages << PAGE_SHIFT; - if (((pa ^ (pa + size - 1)) & ~(boundary - 1)) != 0) - return (NULL); - - /* - * Look for an existing reservation. - */ - rv = vm_reserv_from_object(object, pindex, mpred, &msucc); - if (rv == NULL) - return (NULL); - KASSERT(object != kernel_object || rv->domain == domain, - ("vm_reserv_extend_contig: Domain mismatch from reservation.")); - index = VM_RESERV_INDEX(object, pindex); - /* Does the allocation fit within the reservation? */ - if (index + npages > VM_LEVEL_0_NPAGES) - return (NULL); - domain = rv->domain; - vmd = VM_DOMAIN(domain); - vm_reserv_lock(rv); - if (rv->object != object) - goto out; - m = &rv->pages[index]; - pa = VM_PAGE_TO_PHYS(m); - if (pa < low || pa + size > high || (pa & (alignment - 1)) != 0 || - ((pa ^ (pa + size - 1)) & ~(boundary - 1)) != 0) - goto out; - /* Handle vm_page_rename(m, new_object, ...). */ - for (i = 0; i < npages; i++) { - if (popmap_is_set(rv->popmap, index + i)) - goto out; - } - if (!vm_domain_allocate(vmd, req, npages)) - goto out; - for (i = 0; i < npages; i++) - vm_reserv_populate(rv, index + i); - vm_reserv_unlock(rv); - return (m); - -out: - vm_reserv_unlock(rv); - return (NULL); -} - -/* * Allocates a contiguous set of physical pages of the given size "npages" - * from newly created reservations. 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 @@ -672,18 +585,15 @@ out: * physical address boundary that is a multiple of that value. Both * "alignment" and "boundary" must be a power of two. * - * Callers should first invoke vm_reserv_extend_contig() to attempt an - * allocation from existing reservations. - * * The page "mpred" must immediately precede the offset "pindex" within the * specified object. * - * The object and free page queue must be locked. + * The object must be locked. */ vm_page_t -vm_reserv_alloc_contig(int req, vm_object_t object, vm_pindex_t pindex, int domain, - u_long npages, vm_paddr_t low, vm_paddr_t high, u_long alignment, - vm_paddr_t boundary, vm_page_t mpred) +vm_reserv_alloc_contig(vm_object_t object, vm_pindex_t pindex, int domain, + int req, vm_page_t mpred, u_long npages, vm_paddr_t low, vm_paddr_t high, + u_long alignment, vm_paddr_t boundary) { struct vm_domain *vmd; vm_paddr_t pa, size; @@ -721,13 +631,42 @@ vm_reserv_alloc_contig(int req, vm_object_t object, vm return (NULL); /* - * Callers should've extended an existing reservation prior to - * calling this function. If a reservation exists it is - * incompatible with the allocation. + * Look for an existing reservation. */ rv = vm_reserv_from_object(object, pindex, mpred, &msucc); - if (rv != NULL) + if (rv != NULL) { + KASSERT(object != kernel_object || rv->domain == domain, + ("vm_reserv_alloc_contig: domain mismatch")); + index = VM_RESERV_INDEX(object, pindex); + /* Does the allocation fit within the reservation? */ + if (index + npages > VM_LEVEL_0_NPAGES) + return (NULL); + domain = rv->domain; + vmd = VM_DOMAIN(domain); + vm_reserv_lock(rv); + /* Handle reclaim race. */ + if (rv->object != object) + goto out; + m = &rv->pages[index]; + pa = VM_PAGE_TO_PHYS(m); + if (pa < low || pa + size > high || + (pa & (alignment - 1)) != 0 || + ((pa ^ (pa + size - 1)) & ~(boundary - 1)) != 0) + goto out; + /* Handle vm_page_rename(m, new_object, ...). */ + for (i = 0; i < npages; i++) + if (popmap_is_set(rv->popmap, index + i)) + goto out; + if (!vm_domain_allocate(vmd, req, npages)) + goto out; + for (i = 0; i < npages; i++) + vm_reserv_populate(rv, index + i); + vm_reserv_unlock(rv); + return (m); +out: + vm_reserv_unlock(rv); return (NULL); + } /* * Could at least one reservation fit between the first index to the @@ -849,8 +788,7 @@ vm_reserv_alloc_contig(int req, vm_object_t object, vm } /* - * Attempts to extend an existing reservation and allocate the page to the - * object. + * Allocate a physical page from an existing or newly created reservation. * * The page "mpred" must immediately precede the offset "pindex" within the * specified object. @@ -858,70 +796,11 @@ vm_reserv_alloc_contig(int req, vm_object_t object, vm * The object must be locked. */ vm_page_t -vm_reserv_extend(int req, vm_object_t object, vm_pindex_t pindex, int domain, - vm_page_t mpred) +vm_reserv_alloc_page(vm_object_t object, vm_pindex_t pindex, int domain, + int req, vm_page_t mpred) { struct vm_domain *vmd; vm_page_t m, msucc; - vm_reserv_t rv; - int index; - - VM_OBJECT_ASSERT_WLOCKED(object); - - /* - * Could a reservation currently exist? - */ - if (pindex < VM_RESERV_INDEX(object, pindex) || - pindex >= object->size || object->resident_page_count == 0) - return (NULL); - - /* - * Look for an existing reservation. - */ - rv = vm_reserv_from_object(object, pindex, mpred, &msucc); - if (rv == NULL) - return (NULL); - - KASSERT(object != kernel_object || rv->domain == domain, - ("vm_reserv_extend: Domain mismatch from reservation.")); - domain = rv->domain; - vmd = VM_DOMAIN(domain); - index = VM_RESERV_INDEX(object, pindex); - m = &rv->pages[index]; - vm_reserv_lock(rv); - /* Handle reclaim race. */ - if (rv->object != object || - /* Handle vm_page_rename(m, new_object, ...). */ - popmap_is_set(rv->popmap, index)) { - m = NULL; - goto out; - } - if (vm_domain_allocate(vmd, req, 1) == 0) - m = NULL; - else - vm_reserv_populate(rv, index); -out: - vm_reserv_unlock(rv); - - return (m); -} - -/* - * Attempts to allocate a new reservation for the object, and allocates a - * page from that reservation. Callers should first invoke vm_reserv_extend() - * to attempt an allocation from an existing reservation. - * - * The page "mpred" must immediately precede the offset "pindex" within the - * specified object. - * - * The object and free page queue must be locked. - */ -vm_page_t -vm_reserv_alloc_page(int req, vm_object_t object, vm_pindex_t pindex, int domain, - vm_page_t mpred) -{ - struct vm_domain *vmd; - vm_page_t m, msucc; vm_pindex_t first, leftcap, rightcap; vm_reserv_t rv; int index; @@ -936,13 +815,32 @@ vm_reserv_alloc_page(int req, vm_object_t object, vm_p return (NULL); /* - * Callers should've extended an existing reservation prior to - * calling this function. If a reservation exists it is - * incompatible with the allocation. + * Look for an existing reservation. */ rv = vm_reserv_from_object(object, pindex, mpred, &msucc); - if (rv != NULL) - return (NULL); + if (rv != NULL) { + KASSERT(object != kernel_object || rv->domain == domain, + ("vm_reserv_alloc_page: domain mismatch")); + domain = rv->domain; + vmd = VM_DOMAIN(domain); + index = VM_RESERV_INDEX(object, pindex); + m = &rv->pages[index]; + vm_reserv_lock(rv); + /* Handle reclaim race. */ + if (rv->object != object || + /* Handle vm_page_rename(m, new_object, ...). */ + popmap_is_set(rv->popmap, index)) { + m = NULL; + goto out; + } + if (vm_domain_allocate(vmd, req, 1) == 0) + m = NULL; + else + vm_reserv_populate(rv, index); +out: + vm_reserv_unlock(rv); + return (m); + } /* * Could a reservation fit between the first index to the left that Modified: head/sys/vm/vm_reserv.h ============================================================================== --- head/sys/vm/vm_reserv.h Mon Jun 3 04:38:07 2019 (r348524) +++ head/sys/vm/vm_reserv.h Mon Jun 3 05:15:36 2019 (r348525) @@ -47,17 +47,12 @@ /* * The following functions are only to be used by the virtual memory system. */ -vm_page_t vm_reserv_alloc_contig(int req, vm_object_t object, vm_pindex_t pindex, - int domain, u_long npages, vm_paddr_t low, vm_paddr_t high, - u_long alignment, vm_paddr_t boundary, vm_page_t mpred); -vm_page_t vm_reserv_extend_contig(int req, vm_object_t object, - vm_pindex_t pindex, int domain, u_long npages, +vm_page_t vm_reserv_alloc_contig(vm_object_t object, vm_pindex_t pindex, + int domain, int req, vm_page_t mpred, u_long npages, vm_paddr_t low, vm_paddr_t high, u_long alignment, - vm_paddr_t boundary, vm_page_t mpred); -vm_page_t vm_reserv_alloc_page(int req, vm_object_t object, vm_pindex_t pindex, - int domain, vm_page_t mpred); -vm_page_t vm_reserv_extend(int req, vm_object_t object, - vm_pindex_t pindex, int domain, vm_page_t mpred); + vm_paddr_t boundary); +vm_page_t vm_reserv_alloc_page(vm_object_t object, vm_pindex_t pindex, + int domain, int req, vm_page_t mpred); void vm_reserv_break_all(vm_object_t object); boolean_t vm_reserv_free_page(vm_page_t m); void vm_reserv_init(void);
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