Author: attilio
Date: Mon Apr 8 19:58:32 2013
New Revision: 249277
URL: http://svnweb.freebsd.org/changeset/base/249277
Log:
Switch some "low-hanging fruit" to acquire read lock on vmobjects
rather than write locks.
Sponsored by: EMC / Isilon storage division
Reviewed by: alc
Tested by: pho
Modified:
head/sys/kern/imgact_elf.c
head/sys/kern/kern_proc.c
head/sys/kern/sys_process.c
Modified: head/sys/kern/imgact_elf.c
==============================================================================
--- head/sys/kern/imgact_elf.c Mon Apr 8 19:57:21 2013 (r249276)
+++ head/sys/kern/imgact_elf.c Mon Apr 8 19:58:32 2013 (r249277)
@@ -1277,15 +1277,15 @@ each_writable_segment(td, func, closure)
continue;
/* Ignore memory-mapped devices and such things. */
- VM_OBJECT_WLOCK(object);
+ VM_OBJECT_RLOCK(object);
while ((backing_object = object->backing_object) != NULL) {
- VM_OBJECT_WLOCK(backing_object);
- VM_OBJECT_WUNLOCK(object);
+ VM_OBJECT_RLOCK(backing_object);
+ VM_OBJECT_RUNLOCK(object);
object = backing_object;
}
ignore_entry = object->type != OBJT_DEFAULT &&
object->type != OBJT_SWAP && object->type != OBJT_VNODE;
- VM_OBJECT_WUNLOCK(object);
+ VM_OBJECT_RUNLOCK(object);
if (ignore_entry)
continue;
Modified: head/sys/kern/kern_proc.c
==============================================================================
--- head/sys/kern/kern_proc.c Mon Apr 8 19:57:21 2013 (r249276)
+++ head/sys/kern/kern_proc.c Mon Apr 8 19:58:32 2013 (r249277)
@@ -1995,7 +1995,7 @@ sysctl_kern_proc_ovmmap(SYSCTL_HANDLER_A
kve->kve_private_resident = 0;
obj = entry->object.vm_object;
if (obj != NULL) {
- VM_OBJECT_WLOCK(obj);
+ VM_OBJECT_RLOCK(obj);
if (obj->shadow_count == 1)
kve->kve_private_resident =
obj->resident_page_count;
@@ -2010,9 +2010,9 @@ sysctl_kern_proc_ovmmap(SYSCTL_HANDLER_A
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;
}
@@ -2072,11 +2072,11 @@ sysctl_kern_proc_ovmmap(SYSCTL_HANDLER_A
break;
}
if (lobj != obj)
- VM_OBJECT_WUNLOCK(lobj);
+ VM_OBJECT_RUNLOCK(lobj);
kve->kve_ref_count = obj->ref_count;
kve->kve_shadow_count = obj->shadow_count;
- VM_OBJECT_WUNLOCK(obj);
+ VM_OBJECT_RUNLOCK(obj);
if (vp != NULL) {
vn_fullpath(curthread, vp, &fullpath,
&freepath);
@@ -2162,7 +2162,7 @@ sysctl_kern_proc_vmmap(SYSCTL_HANDLER_AR
kve->kve_private_resident = 0;
obj = entry->object.vm_object;
if (obj != NULL) {
- VM_OBJECT_WLOCK(obj);
+ VM_OBJECT_RLOCK(obj);
if (obj->shadow_count == 1)
kve->kve_private_resident =
obj->resident_page_count;
@@ -2183,9 +2183,9 @@ sysctl_kern_proc_vmmap(SYSCTL_HANDLER_AR
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;
}
@@ -2247,11 +2247,11 @@ sysctl_kern_proc_vmmap(SYSCTL_HANDLER_AR
break;
}
if (lobj != obj)
- VM_OBJECT_WUNLOCK(lobj);
+ VM_OBJECT_RUNLOCK(lobj);
kve->kve_ref_count = obj->ref_count;
kve->kve_shadow_count = obj->shadow_count;
- VM_OBJECT_WUNLOCK(obj);
+ VM_OBJECT_RUNLOCK(obj);
if (vp != NULL) {
vn_fullpath(curthread, vp, &fullpath,
&freepath);
Modified: head/sys/kern/sys_process.c
==============================================================================
--- head/sys/kern/sys_process.c Mon Apr 8 19:57:21 2013 (r249276)
+++ head/sys/kern/sys_process.c Mon Apr 8 19:58:32 2013 (r249277)
@@ -382,7 +382,7 @@ ptrace_vm_entry(struct thread *td, struc
obj = entry->object.vm_object;
if (obj != NULL)
- VM_OBJECT_WLOCK(obj);
+ VM_OBJECT_RLOCK(obj);
} while (0);
vm_map_unlock_read(map);
@@ -395,9 +395,9 @@ ptrace_vm_entry(struct thread *td, struc
lobj = obj;
for (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;
pve->pve_offset += tobj->backing_object_offset;
}
@@ -405,8 +405,8 @@ ptrace_vm_entry(struct thread *td, struc
if (vp != NULL)
vref(vp);
if (lobj != obj)
- VM_OBJECT_WUNLOCK(lobj);
- VM_OBJECT_WUNLOCK(obj);
+ VM_OBJECT_RUNLOCK(lobj);
+ VM_OBJECT_RUNLOCK(obj);
if (vp != NULL) {
freepath = NULL;
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