svn commit: r251423 - in head/sys: compat/linprocfs dev/hwpmc fs/procfs

[Alan Cox]

Author: alc
Date: Wed Jun  5 17:00:10 2013
New Revision: 251423
URL: http://svnweb.freebsd.org/changeset/base/251423

Log:
  Relax the vm object locking.  Use a read lock.
  
  Sponsored by:	EMC / Isilon Storage Division

Modified:
  head/sys/compat/linprocfs/linprocfs.c
  head/sys/dev/hwpmc/hwpmc_mod.c
  head/sys/fs/procfs/procfs_map.c

Modified: head/sys/compat/linprocfs/linprocfs.c
==============================================================================
--- head/sys/compat/linprocfs/linprocfs.c	Wed Jun  5 16:12:50 2013	(r251422)
+++ head/sys/compat/linprocfs/linprocfs.c	Wed Jun  5 17:00:10 2013	(r251423)
@@ -1031,9 +1031,9 @@ linprocfs_doprocmaps(PFS_FILL_ARGS)
 		e_end = entry->end;
 		obj = entry->object.vm_object;
 		for (lobj = tobj = obj; tobj; tobj = tobj->backing_object) {
-			VM_OBJECT_WLOCK(tobj);
+			VM_OBJECT_RLOCK(tobj);
 			if (lobj != obj)
-				VM_OBJECT_WUNLOCK(lobj);
+				VM_OBJECT_RUNLOCK(lobj);
 			lobj = tobj;
 		}
 		last_timestamp = map->timestamp;
@@ -1049,11 +1049,11 @@ linprocfs_doprocmaps(PFS_FILL_ARGS)
 			else
 				vp = NULL;
 			if (lobj != obj)
-				VM_OBJECT_WUNLOCK(lobj);
+				VM_OBJECT_RUNLOCK(lobj);
 			flags = obj->flags;
 			ref_count = obj->ref_count;
 			shadow_count = obj->shadow_count;
-			VM_OBJECT_WUNLOCK(obj);
+			VM_OBJECT_RUNLOCK(obj);
 			if (vp) {
 				vn_fullpath(td, vp, &name, &freename);
 				vn_lock(vp, LK_SHARED | LK_RETRY);

Modified: head/sys/dev/hwpmc/hwpmc_mod.c
==============================================================================
--- head/sys/dev/hwpmc/hwpmc_mod.c	Wed Jun  5 16:12:50 2013	(r251422)
+++ head/sys/dev/hwpmc/hwpmc_mod.c	Wed Jun  5 17:00:10 2013	(r251423)
@@ -1672,7 +1672,7 @@ pmc_log_process_mappings(struct pmc_owne
 		}
 
 		obj = entry->object.vm_object;
-		VM_OBJECT_WLOCK(obj);
+		VM_OBJECT_RLOCK(obj);
 
 		/* 
 		 * Walk the backing_object list to find the base
@@ -1680,9 +1680,9 @@ pmc_log_process_mappings(struct pmc_owne
 		 */
 		for (lobj = tobj = obj; tobj != NULL; tobj = tobj->backing_object) {
 			if (tobj != obj)
-				VM_OBJECT_WLOCK(tobj);
+				VM_OBJECT_RLOCK(tobj);
 			if (lobj != obj)
-				VM_OBJECT_WUNLOCK(lobj);
+				VM_OBJECT_RUNLOCK(lobj);
 			lobj = tobj;
 		}
 
@@ -1692,14 +1692,14 @@ pmc_log_process_mappings(struct pmc_owne
 		if (lobj == NULL) {
 			PMCDBG(LOG,OPS,2, "hwpmc: lobj unexpectedly NULL! pid=%d "
 			    "vm_map=%p vm_obj=%p\n", p->p_pid, map, obj);
-			VM_OBJECT_WUNLOCK(obj);
+			VM_OBJECT_RUNLOCK(obj);
 			continue;
 		}
 
 		if (lobj->type != OBJT_VNODE || lobj->handle == NULL) {
 			if (lobj != obj)
-				VM_OBJECT_WUNLOCK(lobj);
-			VM_OBJECT_WUNLOCK(obj);
+				VM_OBJECT_RUNLOCK(lobj);
+			VM_OBJECT_RUNLOCK(obj);
 			continue;
 		}
 
@@ -1711,8 +1711,8 @@ pmc_log_process_mappings(struct pmc_owne
 		if (entry->start == last_end && lobj->handle == last_vp) {
 			last_end = entry->end;
 			if (lobj != obj)
-				VM_OBJECT_WUNLOCK(lobj);
-			VM_OBJECT_WUNLOCK(obj);
+				VM_OBJECT_RUNLOCK(lobj);
+			VM_OBJECT_RUNLOCK(obj);
 			continue;
 		}
 
@@ -1734,9 +1734,9 @@ pmc_log_process_mappings(struct pmc_owne
 		vp = lobj->handle;
 		vref(vp);
 		if (lobj != obj)
-			VM_OBJECT_WUNLOCK(lobj);
+			VM_OBJECT_RUNLOCK(lobj);
 
-		VM_OBJECT_WUNLOCK(obj);
+		VM_OBJECT_RUNLOCK(obj);
 
 		freepath = NULL;
 		pmc_getfilename(vp, &fullpath, &freepath);

Modified: head/sys/fs/procfs/procfs_map.c
==============================================================================
--- head/sys/fs/procfs/procfs_map.c	Wed Jun  5 16:12:50 2013	(r251422)
+++ head/sys/fs/procfs/procfs_map.c	Wed Jun  5 17:00:10 2013	(r251423)
@@ -132,7 +132,7 @@ procfs_doprocmap(PFS_FILL_ARGS)
 		privateresident = 0;
 		obj = entry->object.vm_object;
 		if (obj != NULL) {
-			VM_OBJECT_WLOCK(obj);
+			VM_OBJECT_RLOCK(obj);
 			if (obj->shadow_count == 1)
 				privateresident = obj->resident_page_count;
 		}
@@ -148,9 +148,9 @@ procfs_doprocmap(PFS_FILL_ARGS)
 
 		for (lobj = tobj = obj; tobj; tobj = tobj->backing_object) {
 			if (tobj != obj)
-				VM_OBJECT_WLOCK(tobj);
+				VM_OBJECT_RLOCK(tobj);
 			if (lobj != obj)
-				VM_OBJECT_WUNLOCK(lobj);
+				VM_OBJECT_RUNLOCK(lobj);
 			lobj = tobj;
 		}
 		last_timestamp = map->timestamp;
@@ -181,12 +181,12 @@ procfs_doprocmap(PFS_FILL_ARGS)
 				break;
 			}
 			if (lobj != obj)
-				VM_OBJECT_WUNLOCK(lobj);
+				VM_OBJECT_RUNLOCK(lobj);
 
 			flags = obj->flags;
 			ref_count = obj->ref_count;
 			shadow_count = obj->shadow_count;
-			VM_OBJECT_WUNLOCK(obj);
+			VM_OBJECT_RUNLOCK(obj);
 			if (vp != NULL) {
 				vn_fullpath(td, vp, &fullpath, &freepath);
 				vrele(vp);