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authorattilio <attilio@FreeBSD.org>2013-03-09 02:32:23 +0000
committerattilio <attilio@FreeBSD.org>2013-03-09 02:32:23 +0000
commit72f7f3e528d2e900546a7ccbe16525b12d64dd44 (patch)
tree382de98b1c7b142a92ed9c04ab1ea90d5a1c3a06 /sys/vm/vm_reserv.c
parent754f3790b85afd6cd15e69b91ee97848364f75f5 (diff)
parent49c5854731cc608c08a92b35c6e2be2825c64a6c (diff)
downloadFreeBSD-src-72f7f3e528d2e900546a7ccbe16525b12d64dd44.zip
FreeBSD-src-72f7f3e528d2e900546a7ccbe16525b12d64dd44.tar.gz
Switch the vm_object mutex to be a rwlock. This will enable in the
future further optimizations where the vm_object lock will be held in read mode most of the time the page cache resident pool of pages are accessed for reading purposes. The change is mostly mechanical but few notes are reported: * The KPI changes as follow: - VM_OBJECT_LOCK() -> VM_OBJECT_WLOCK() - VM_OBJECT_TRYLOCK() -> VM_OBJECT_TRYWLOCK() - VM_OBJECT_UNLOCK() -> VM_OBJECT_WUNLOCK() - VM_OBJECT_LOCK_ASSERT(MA_OWNED) -> VM_OBJECT_ASSERT_WLOCKED() (in order to avoid visibility of implementation details) - The read-mode operations are added: VM_OBJECT_RLOCK(), VM_OBJECT_TRYRLOCK(), VM_OBJECT_RUNLOCK(), VM_OBJECT_ASSERT_RLOCKED(), VM_OBJECT_ASSERT_LOCKED() * The vm/vm_pager.h namespace pollution avoidance (forcing requiring sys/mutex.h in consumers directly to cater its inlining functions using VM_OBJECT_LOCK()) imposes that all the vm/vm_pager.h consumers now must include also sys/rwlock.h. * zfs requires a quite convoluted fix to include FreeBSD rwlocks into the compat layer because the name clash between FreeBSD and solaris versions must be avoided. At this purpose zfs redefines the vm_object locking functions directly, isolating the FreeBSD components in specific compat stubs. The KPI results heavilly broken by this commit. Thirdy part ports must be updated accordingly (I can think off-hand of VirtualBox, for example). Sponsored by: EMC / Isilon storage division Reviewed by: jeff Reviewed by: pjd (ZFS specific review) Discussed with: alc Tested by: pho
Diffstat (limited to 'sys/vm/vm_reserv.c')
-rw-r--r--sys/vm/vm_reserv.c7
1 files changed, 4 insertions, 3 deletions
diff --git a/sys/vm/vm_reserv.c b/sys/vm/vm_reserv.c
index e5ac1a5..98b0de2 100644
--- a/sys/vm/vm_reserv.c
+++ b/sys/vm/vm_reserv.c
@@ -47,6 +47,7 @@ __FBSDID("$FreeBSD$");
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/queue.h>
+#include <sys/rwlock.h>
#include <sys/sbuf.h>
#include <sys/sysctl.h>
#include <sys/systm.h>
@@ -311,7 +312,7 @@ vm_reserv_alloc_contig(vm_object_t object, vm_pindex_t pindex, u_long npages,
int i, index, n;
mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
- VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
+ VM_OBJECT_ASSERT_WLOCKED(object);
KASSERT(npages != 0, ("vm_reserv_alloc_contig: npages is 0"));
/*
@@ -495,7 +496,7 @@ vm_reserv_alloc_page(vm_object_t object, vm_pindex_t pindex)
vm_reserv_t rv;
mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
- VM_OBJECT_LOCK_ASSERT(object, MA_OWNED);
+ VM_OBJECT_ASSERT_WLOCKED(object);
/*
* Is a reservation fundamentally impossible?
@@ -870,7 +871,7 @@ vm_reserv_rename(vm_page_t m, vm_object_t new_object, vm_object_t old_object,
{
vm_reserv_t rv;
- VM_OBJECT_LOCK_ASSERT(new_object, MA_OWNED);
+ VM_OBJECT_ASSERT_WLOCKED(new_object);
rv = vm_reserv_from_page(m);
if (rv->object == old_object) {
mtx_lock(&vm_page_queue_free_mtx);
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