[haiku-commits] r35322 - haiku/trunk/src/system/kernel/vm
- From: ingo_weinhold@xxxxxx
- To: haiku-commits@xxxxxxxxxxxxx
- Date: Wed, 27 Jan 2010 21:55:02 +0100 (CET)
Author: bonefish
Date: 2010-01-27 21:55:02 +0100 (Wed, 27 Jan 2010)
New Revision: 35322
Changeset: http://dev.haiku-os.org/changeset/35322/haiku
Modified:
haiku/trunk/src/system/kernel/vm/vm_page.cpp
Log:
* Improved the clarity of some loops in the page reservation functions. No
functional change (other than avoiding no-ops like subtracting 0).
* vm_page_try_reserve_pages(): Moved the kernel tracing calls from the top of
the function to the points where the reservation already succeeded.
Modified: haiku/trunk/src/system/kernel/vm/vm_page.cpp
===================================================================
--- haiku/trunk/src/system/kernel/vm/vm_page.cpp 2010-01-27 19:04:46 UTC
(rev 35321)
+++ haiku/trunk/src/system/kernel/vm/vm_page.cpp 2010-01-27 20:55:02 UTC
(rev 35322)
@@ -2171,21 +2171,20 @@
uint32 systemReserve = kPageReserveForPriority[priority];
while (true) {
int32 systemFreePages = sSystemReservedPages;
- uint32 toReserve = 0;
if (systemFreePages > (int32)systemReserve) {
- toReserve = std::min(count, systemFreePages -
systemReserve);
+ uint32 toReserve = std::min(count, systemFreePages -
systemReserve);
if (atomic_test_and_set(&sSystemReservedPages,
systemFreePages - toReserve,
systemFreePages)
!= systemFreePages) {
// the count changed in the meantime -- retry
continue;
}
+
+ count -= toReserve;
+ if (count == 0)
+ return;
}
- count -= toReserve;
- if (count == 0)
- return;
-
break;
}
@@ -2210,13 +2209,11 @@
if (count == 0)
return true;
- T(ReservePages(count));
-
+ uint32 reserved;
while (true) {
// From the requested count reserve as many pages as possible
from the
// general reserve.
int32 freePages = sUnreservedFreePages;
- uint32 reserved = 0;
if (freePages > 0) {
reserved = std::min((int32)count, freePages);
if (atomic_test_and_set(&sUnreservedFreePages,
@@ -2225,31 +2222,36 @@
// the count changed in the meantime -- retry
continue;
}
- }
- if (reserved == count)
- return true;
-
- // Try to get the remaining pages from the system reserve.
- uint32 systemReserve = kPageReserveForPriority[priority];
- uint32 leftToReserve = count - reserved;
- while (true) {
- int32 systemFreePages = sSystemReservedPages;
- if ((uint32)systemFreePages < leftToReserve +
systemReserve) {
- // no dice
- vm_page_unreserve_pages(reserved);
- return false;
- }
-
- if (atomic_test_and_set(&sSystemReservedPages,
- systemFreePages -
leftToReserve, systemFreePages)
- == systemFreePages) {
+ if (reserved == count) {
+ T(ReservePages(count));
return true;
}
+ } else
+ reserved = 0;
- // the count changed in the meantime -- retry
- continue;
+ break;
+ }
+
+ // Try to get the remaining pages from the system reserve.
+ uint32 systemReserve = kPageReserveForPriority[priority];
+ uint32 leftToReserve = count - reserved;
+ while (true) {
+ int32 systemFreePages = sSystemReservedPages;
+ if ((uint32)systemFreePages < leftToReserve + systemReserve) {
+ // no dice
+ vm_page_unreserve_pages(reserved);
+ return false;
}
+
+ if (atomic_test_and_set(&sSystemReservedPages,
+ systemFreePages - leftToReserve,
systemFreePages)
+ == systemFreePages) {
+ T(ReservePages(count));
+ return true;
+ }
+
+ // the count changed in the meantime -- retry
}
}
Other related posts:
- » [haiku-commits] r35322 - haiku/trunk/src/system/kernel/vm - ingo_weinhold
