The branch main has been updated by dougm:
URL:
https://cgit.FreeBSD.org/src/commit/?id=c6c63b92effd6d0662977f11bf429127b9dc4407
commit c6c63b92effd6d0662977f11bf429127b9dc4407
Author: Doug Moore <do...@freebsd.org>
AuthorDate: 2025-03-04 05:31:18 +0000
Commit: Doug Moore <do...@freebsd.org>
CommitDate: 2025-03-04 05:31:18 +0000
vm_object: don't reset new iterator
Don't call pctrie_iter_reset on a just-initialized iterator. Let the
code jumping back up do the resetting. Add an assertion at the jump
destination to check that a reset happened.
Reviewed by: kib
Differential Revision: https://reviews.freebsd.org/D49207
---
sys/sys/pctrie.h | 6 ++++++
sys/vm/device_pager.c | 2 ++
sys/vm/vm_object.c | 9 +++++++--
3 files changed, 15 insertions(+), 2 deletions(-)
diff --git a/sys/sys/pctrie.h b/sys/sys/pctrie.h
index 42473dc8e632..dac18b58498b 100644
--- a/sys/sys/pctrie.h
+++ b/sys/sys/pctrie.h
@@ -47,6 +47,12 @@ pctrie_iter_reset(struct pctrie_iter *it)
it->node = NULL;
}
+static __inline bool
+pctrie_iter_is_reset(struct pctrie_iter *it)
+{
+ return (it->node == NULL);
+}
+
static __inline void
pctrie_iter_init(struct pctrie_iter *it, struct pctrie *ptree)
{
diff --git a/sys/vm/device_pager.c b/sys/vm/device_pager.c
index 0691d43a5946..0b3a2eb54d75 100644
--- a/sys/vm/device_pager.c
+++ b/sys/vm/device_pager.c
@@ -293,6 +293,8 @@ cdev_mgtdev_pager_free_pages(vm_object_t object)
vm_page_iter_init(&pages, object);
VM_OBJECT_WLOCK(object);
retry:
+ KASSERT(pctrie_iter_is_reset(&pages),
+ ("%s: pctrie_iter not reset for retry", __func__));
for (m = vm_radix_iter_lookup_ge(&pages, 0); m != NULL;
m = vm_radix_iter_step(&pages)) {
if (!vm_page_busy_acquire(m, VM_ALLOC_WAITFAIL)) {
diff --git a/sys/vm/vm_object.c b/sys/vm/vm_object.c
index 9269103d8d91..79a28c4d77b0 100644
--- a/sys/vm/vm_object.c
+++ b/sys/vm/vm_object.c
@@ -1576,7 +1576,8 @@ vm_object_split(vm_map_entry_t entry)
vm_object_set_flag(orig_object, OBJ_SPLIT);
vm_page_iter_limit_init(&pages, orig_object, offidxstart + size);
retry:
- pctrie_iter_reset(&pages);
+ KASSERT(pctrie_iter_is_reset(&pages),
+ ("%s: pctrie_iter not reset for retry", __func__));
for (m = vm_radix_iter_lookup_ge(&pages, offidxstart); m != NULL;
m = vm_radix_iter_step(&pages)) {
/*
@@ -1590,6 +1591,7 @@ retry:
VM_OBJECT_WUNLOCK(new_object);
if (vm_page_busy_sleep(m, "spltwt", 0))
VM_OBJECT_WLOCK(orig_object);
+ pctrie_iter_reset(&pages);
VM_OBJECT_WLOCK(new_object);
goto retry;
}
@@ -1611,6 +1613,7 @@ retry:
VM_OBJECT_WUNLOCK(new_object);
VM_OBJECT_WUNLOCK(orig_object);
vm_radix_wait();
+ pctrie_iter_reset(&pages);
VM_OBJECT_WLOCK(orig_object);
VM_OBJECT_WLOCK(new_object);
goto retry;
@@ -1996,7 +1999,8 @@ vm_object_page_remove(vm_object_t object, vm_pindex_t
start, vm_pindex_t end,
vm_object_pip_add(object, 1);
vm_page_iter_limit_init(&pages, object, end);
again:
- pctrie_iter_reset(&pages);
+ KASSERT(pctrie_iter_is_reset(&pages),
+ ("%s: pctrie_iter not reset for retry", __func__));
for (p = vm_radix_iter_lookup_ge(&pages, start); p != NULL;
p = vm_radix_iter_step(&pages)) {
/*
@@ -2025,6 +2029,7 @@ again:
if (vm_page_tryxbusy(p) == 0) {
if (vm_page_busy_sleep(p, "vmopar", 0))
VM_OBJECT_WLOCK(object);
+ pctrie_iter_reset(&pages);
goto again;
}
if ((options & OBJPR_VALIDONLY) != 0 && vm_page_none_valid(p)) {
