The branch main has been updated by dougm:
URL:
https://cgit.FreeBSD.org/src/commit/?id=557dc337e6cb6664a322c3988632b5ca75ff33ed
commit 557dc337e6cb6664a322c3988632b5ca75ff33ed
Author: Doug Moore <do...@freebsd.org>
AuthorDate: 2022-03-31 21:19:55 +0000
Commit: Doug Moore <do...@freebsd.org>
CommitDate: 2022-03-31 21:19:55 +0000
vm_phys: check small blocks to finish allocation
In vm_phys_alloc_queues_contig, in the case that a sequence of
max-order blocks are sought to fulfill an allocation, a sequence is
ruled out if it does not have enough max-order blocks to satisfy the
allocation. However, there may be smaller blocks of free memory that
follow the last max-order block in the sequence, and they may be big
enough to complete the allocation request, so check for that
possibility before giving up on that block sequence.
Reviewed by: markj
Tested by: pho
Differential Revision: https://reviews.freebsd.org/D34724
---
sys/vm/vm_phys.c | 24 +++++++++++++++++++++---
1 file changed, 21 insertions(+), 3 deletions(-)
diff --git a/sys/vm/vm_phys.c b/sys/vm/vm_phys.c
index 1f4c228b1a84..33c46fe7c481 100644
--- a/sys/vm/vm_phys.c
+++ b/sys/vm/vm_phys.c
@@ -1405,9 +1405,9 @@ vm_phys_alloc_queues_contig(
continue;
/*
- * Determine if a sufficient number of
- * subsequent blocks to satisfy the
- * allocation request are free.
+ * Determine if a series of free oind-blocks
+ * starting here can satisfy the allocation
+ * request.
*/
do {
pa += 1 <<
@@ -1416,6 +1416,23 @@ vm_phys_alloc_queues_contig(
goto done;
} while (VM_NFREEORDER - 1 == seg->first_page[
atop(pa - seg->start)].order);
+
+ /*
+ * Determine if an additional series of free
+ * blocks of diminishing size can help to
+ * satisfy the allocation request.
+ */
+ for (;;) {
+ m = &seg->first_page[
+ atop(pa - seg->start)];
+ if (m->order == VM_NFREEORDER ||
+ pa + (2 << (PAGE_SHIFT + m->order))
+ <= pa_end)
+ break;
+ pa += 1 << (PAGE_SHIFT + m->order);
+ if (pa >= pa_end)
+ goto done;
+ }
}
}
}
@@ -1423,6 +1440,7 @@ vm_phys_alloc_queues_contig(
done:
for (m = m_ret; m < &m_ret[npages]; m = &m[1 << oind]) {
fl = (*queues)[m->pool];
+ oind = m->order;
vm_freelist_rem(fl, m, oind);
if (m->pool != VM_FREEPOOL_DEFAULT)
vm_phys_set_pool(VM_FREEPOOL_DEFAULT, m, oind);
