Author: jeff Date: Tue Oct 15 03:48:22 2019 New Revision: 353540 URL: https://svnweb.freebsd.org/changeset/base/353540
Log: (5/6) Move the VPO_NOSYNC to PGA_NOSYNC to eliminate the dependency on the object lock in vm_page_set_validclean(). Reviewed by: kib, markj Tested by: pho Sponsored by: Netflix, Intel Differential Revision: https://reviews.freebsd.org/D21595 Modified: head/sys/vm/vm_fault.c head/sys/vm/vm_object.c head/sys/vm/vm_object.h head/sys/vm/vm_page.c head/sys/vm/vm_page.h Modified: head/sys/vm/vm_fault.c ============================================================================== --- head/sys/vm/vm_fault.c Tue Oct 15 03:45:41 2019 (r353539) +++ head/sys/vm/vm_fault.c Tue Oct 15 03:48:22 2019 (r353540) @@ -225,15 +225,14 @@ vm_fault_dirty(vm_map_entry_t entry, vm_page_t m, vm_p * FALSE, one for the map entry with MAP_ENTRY_NOSYNC * flag set, other with flag clear, race, it is * possible for the no-NOSYNC thread to see m->dirty - * != 0 and not clear VPO_NOSYNC. Take vm_page lock - * around manipulation of VPO_NOSYNC and - * vm_page_dirty() call, to avoid the race and keep - * m->oflags consistent. + * != 0 and not clear PGA_NOSYNC. Take vm_page lock + * around manipulation of PGA_NOSYNC and + * vm_page_dirty() call to avoid the race. */ vm_page_lock(m); /* - * If this is a NOSYNC mmap we do not want to set VPO_NOSYNC + * If this is a NOSYNC mmap we do not want to set PGA_NOSYNC * if the page is already dirty to prevent data written with * the expectation of being synced from not being synced. * Likewise if this entry does not request NOSYNC then make @@ -242,10 +241,10 @@ vm_fault_dirty(vm_map_entry_t entry, vm_page_t m, vm_p */ if ((entry->eflags & MAP_ENTRY_NOSYNC) != 0) { if (m->dirty == 0) { - m->oflags |= VPO_NOSYNC; + vm_page_aflag_set(m, PGA_NOSYNC); } } else { - m->oflags &= ~VPO_NOSYNC; + vm_page_aflag_clear(m, PGA_NOSYNC); } /* Modified: head/sys/vm/vm_object.c ============================================================================== --- head/sys/vm/vm_object.c Tue Oct 15 03:45:41 2019 (r353539) +++ head/sys/vm/vm_object.c Tue Oct 15 03:48:22 2019 (r353540) @@ -772,12 +772,14 @@ static boolean_t vm_object_page_remove_write(vm_page_t p, int flags, boolean_t *clearobjflags) { + vm_page_assert_busied(p); + /* * If we have been asked to skip nosync pages and this is a * nosync page, skip it. Note that the object flags were not * cleared in this case so we do not have to set them. */ - if ((flags & OBJPC_NOSYNC) != 0 && (p->oflags & VPO_NOSYNC) != 0) { + if ((flags & OBJPC_NOSYNC) != 0 && (p->aflags & PGA_NOSYNC) != 0) { *clearobjflags = FALSE; return (FALSE); } else { @@ -791,7 +793,7 @@ vm_object_page_remove_write(vm_page_t p, int flags, bo * * Clean all dirty pages in the specified range of object. Leaves page * on whatever queue it is currently on. If NOSYNC is set then do not - * write out pages with VPO_NOSYNC set (originally comes from MAP_NOSYNC), + * write out pages with PGA_NOSYNC set (originally comes from MAP_NOSYNC), * leaving the object dirty. * * When stuffing pages asynchronously, allow clustering. XXX we need a @@ -2270,7 +2272,6 @@ void vm_object_unbusy(vm_object_t obj) { - VM_OBJECT_ASSERT_LOCKED(obj); refcount_release(&obj->busy); } Modified: head/sys/vm/vm_object.h ============================================================================== --- head/sys/vm/vm_object.h Tue Oct 15 03:45:41 2019 (r353539) +++ head/sys/vm/vm_object.h Tue Oct 15 03:48:22 2019 (r353540) @@ -209,7 +209,7 @@ struct vm_object { #define OBJPC_SYNC 0x1 /* sync I/O */ #define OBJPC_INVAL 0x2 /* invalidate */ -#define OBJPC_NOSYNC 0x4 /* skip if VPO_NOSYNC */ +#define OBJPC_NOSYNC 0x4 /* skip if PGA_NOSYNC */ /* * The following options are supported by vm_object_page_remove(). Modified: head/sys/vm/vm_page.c ============================================================================== --- head/sys/vm/vm_page.c Tue Oct 15 03:45:41 2019 (r353539) +++ head/sys/vm/vm_page.c Tue Oct 15 03:48:22 2019 (r353540) @@ -2506,7 +2506,7 @@ retry: KASSERT((m->oflags & (VPO_SWAPINPROG | VPO_SWAPSLEEP | VPO_UNMANAGED)) == 0, ("page %p has unexpected oflags", m)); - /* Don't care: VPO_NOSYNC. */ + /* Don't care: PGA_NOSYNC. */ run_ext = 1; } else run_ext = 0; @@ -2655,7 +2655,7 @@ retry: KASSERT((m->oflags & (VPO_SWAPINPROG | VPO_SWAPSLEEP | VPO_UNMANAGED)) == 0, ("page %p has unexpected oflags", m)); - /* Don't care: VPO_NOSYNC. */ + /* Don't care: PGA_NOSYNC. */ if (!vm_page_none_valid(m)) { /* * First, try to allocate a new page @@ -2721,7 +2721,6 @@ retry: ~PGA_QUEUE_STATE_MASK; KASSERT(m_new->oflags == VPO_UNMANAGED, ("page %p is managed", m_new)); - m_new->oflags = m->oflags & VPO_NOSYNC; pmap_copy_page(m, m_new); m_new->valid = m->valid; m_new->dirty = m->dirty; @@ -4703,8 +4702,6 @@ vm_page_set_validclean(vm_page_t m, int base, int size vm_page_bits_t oldvalid, pagebits; int endoff, frag; - /* Object lock for VPO_NOSYNC */ - VM_OBJECT_ASSERT_WLOCKED(m->object); vm_page_assert_busied(m); if (size == 0) /* handle degenerate case */ return; @@ -4732,7 +4729,7 @@ vm_page_set_validclean(vm_page_t m, int base, int size /* * Set valid, clear dirty bits. If validating the entire * page we can safely clear the pmap modify bit. We also - * use this opportunity to clear the VPO_NOSYNC flag. If a process + * use this opportunity to clear the PGA_NOSYNC flag. If a process * takes a write fault on a MAP_NOSYNC memory area the flag will * be set again. * @@ -4773,7 +4770,7 @@ vm_page_set_validclean(vm_page_t m, int base, int size */ pmap_clear_modify(m); m->dirty = 0; - m->oflags &= ~VPO_NOSYNC; + vm_page_aflag_clear(m, PGA_NOSYNC); } else if (oldvalid != VM_PAGE_BITS_ALL && vm_page_xbusied(m)) m->dirty &= ~pagebits; else Modified: head/sys/vm/vm_page.h ============================================================================== --- head/sys/vm/vm_page.h Tue Oct 15 03:45:41 2019 (r353539) +++ head/sys/vm/vm_page.h Tue Oct 15 03:48:22 2019 (r353540) @@ -287,7 +287,6 @@ struct vm_page { #define VPO_SWAPSLEEP 0x02 /* waiting for swap to finish */ #define VPO_UNMANAGED 0x04 /* no PV management for page */ #define VPO_SWAPINPROG 0x08 /* swap I/O in progress on page */ -#define VPO_NOSYNC 0x10 /* do not collect for syncer */ /* * Busy page implementation details. @@ -390,6 +389,8 @@ extern struct mtx_padalign pa_lock[]; * PGA_EXECUTABLE may be set by pmap routines, and indicates that a page has * at least one executable mapping. It is not consumed by the MI VM layer. * + * PGA_NOSYNC must be set and cleared with the page busy lock held. + * * PGA_ENQUEUED is set and cleared when a page is inserted into or removed * from a page queue, respectively. It determines whether the plinks.q field * of the page is valid. To set or clear this flag, the queue lock for the @@ -420,6 +421,7 @@ extern struct mtx_padalign pa_lock[]; #define PGA_DEQUEUE 0x10 /* page is due to be dequeued */ #define PGA_REQUEUE 0x20 /* page is due to be requeued */ #define PGA_REQUEUE_HEAD 0x40 /* page requeue should bypass LRU */ +#define PGA_NOSYNC 0x80 /* do not collect for syncer */ #define PGA_QUEUE_STATE_MASK (PGA_ENQUEUED | PGA_DEQUEUE | PGA_REQUEUE | \ PGA_REQUEUE_HEAD) _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
