Date: Sun, 19 May 2013 14:59:24 +0000 (UTC) From: Attilio Rao <attilio@FreeBSD.org> To: src-committers@freebsd.org, svn-src-user@freebsd.org Subject: svn commit: r250807 - user/attilio/vmobj-readlock/sys/vm Message-ID: <201305191459.r4JExOkh007506@svn.freebsd.org>
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Author: attilio Date: Sun May 19 14:59:24 2013 New Revision: 250807 URL: http://svnweb.freebsd.org/changeset/base/250807 Log: Remove the necessity to define VM_OBJECT_LOCK_DOWNGRADE() and handle the race differently. Sponsored by: EMC / Isilon storage division Modified: user/attilio/vmobj-readlock/sys/vm/vm_map.c user/attilio/vmobj-readlock/sys/vm/vm_object.h Modified: user/attilio/vmobj-readlock/sys/vm/vm_map.c ============================================================================== --- user/attilio/vmobj-readlock/sys/vm/vm_map.c Sun May 19 07:44:01 2013 (r250806) +++ user/attilio/vmobj-readlock/sys/vm/vm_map.c Sun May 19 14:59:24 2013 (r250807) @@ -1806,6 +1806,7 @@ vm_map_pmap_enter(vm_map_t map, vm_offse if ((prot & (VM_PROT_READ | VM_PROT_EXECUTE)) == 0 || object == NULL) return; +relock: VM_OBJECT_RLOCK(object); if (object->type == OBJT_DEVICE || object->type == OBJT_SG) { VM_OBJECT_RUNLOCK(object); @@ -1816,7 +1817,8 @@ vm_map_pmap_enter(vm_map_t map, vm_offse VM_OBJECT_WUNLOCK(object); return; } - VM_OBJECT_LOCK_DOWNGRADE(object); + VM_OBJECT_WUNLOCK(object); + goto relock; } psize = atop(size); Modified: user/attilio/vmobj-readlock/sys/vm/vm_object.h ============================================================================== --- user/attilio/vmobj-readlock/sys/vm/vm_object.h Sun May 19 07:44:01 2013 (r250806) +++ user/attilio/vmobj-readlock/sys/vm/vm_object.h Sun May 19 14:59:24 2013 (r250807) @@ -223,8 +223,6 @@ extern struct vm_object kmem_object_stor rw_assert(&(object)->lock, RA_RLOCKED) #define VM_OBJECT_ASSERT_WLOCKED(object) \ rw_assert(&(object)->lock, RA_WLOCKED) -#define VM_OBJECT_LOCK_DOWNGRADE(object) \ - rw_downgrade(&(object)->lock) #define VM_OBJECT_RLOCK(object) \ rw_rlock(&(object)->lock) #define VM_OBJECT_RUNLOCK(object) \
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