The branch main has been updated by bnovkov:
URL:
https://cgit.FreeBSD.org/src/commit/?id=92b9138991dd2829ac744592cb9f9f3415be146c
commit 92b9138991dd2829ac744592cb9f9f3415be146c
Author: Bojan Novković <bnov...@freebsd.org>
AuthorDate: 2024-07-14 13:13:56 +0000
Commit: Bojan Novković <bnov...@freebsd.org>
CommitDate: 2024-07-30 15:38:24 +0000
vm: Introduce VM_ALLOC_NOFREE and PG_NOFREE
This patch adds two additional vm_page flags to distinguish pages that
never get released while the system is running (e.g. UMA_ZONE_NOFREE slabs).
Differential Revision: https://reviews.freebsd.org/D45970
Reviewed by: alc, kib, markj
Tested by: alc
---
sys/vm/vm_page.c | 13 ++++++++++---
sys/vm/vm_page.h | 5 ++++-
2 files changed, 14 insertions(+), 4 deletions(-)
diff --git a/sys/vm/vm_page.c b/sys/vm/vm_page.c
index 64413ba10bfa..3b6b88e4eb32 100644
--- a/sys/vm/vm_page.c
+++ b/sys/vm/vm_page.c
@@ -2082,7 +2082,8 @@ vm_page_alloc_domain_after(vm_object_t object,
vm_pindex_t pindex, int domain,
#define VPA_FLAGS (VM_ALLOC_CLASS_MASK | VM_ALLOC_WAITFAIL |
\
VM_ALLOC_NOWAIT | VM_ALLOC_NOBUSY | \
VM_ALLOC_SBUSY | VM_ALLOC_WIRED | \
- VM_ALLOC_NODUMP | VM_ALLOC_ZERO | VM_ALLOC_COUNT_MASK)
+ VM_ALLOC_NODUMP | VM_ALLOC_ZERO | \
+ VM_ALLOC_NOFREE | VM_ALLOC_COUNT_MASK)
KASSERT((req & ~VPA_FLAGS) == 0,
("invalid request %#x", req));
KASSERT(((req & (VM_ALLOC_NOBUSY | VM_ALLOC_SBUSY)) !=
@@ -2154,6 +2155,8 @@ found:
flags |= m->flags & PG_ZERO;
if ((req & VM_ALLOC_NODUMP) != 0)
flags |= PG_NODUMP;
+ if ((req & VM_ALLOC_NOFREE) != 0)
+ flags |= PG_NOFREE;
m->flags = flags;
m->a.flags = 0;
m->oflags = (object->flags & OBJ_UNMANAGED) != 0 ? VPO_UNMANAGED : 0;
@@ -2418,11 +2421,13 @@ vm_page_alloc_noobj_domain(int domain, int req)
#define VPAN_FLAGS (VM_ALLOC_CLASS_MASK | VM_ALLOC_WAITFAIL |
\
VM_ALLOC_NOWAIT | VM_ALLOC_WAITOK | \
VM_ALLOC_NOBUSY | VM_ALLOC_WIRED | \
- VM_ALLOC_NODUMP | VM_ALLOC_ZERO | VM_ALLOC_COUNT_MASK)
+ VM_ALLOC_NODUMP | VM_ALLOC_ZERO | \
+ VM_ALLOC_NOFREE | VM_ALLOC_COUNT_MASK)
KASSERT((req & ~VPAN_FLAGS) == 0,
("invalid request %#x", req));
- flags = (req & VM_ALLOC_NODUMP) != 0 ? PG_NODUMP : 0;
+ flags = ((req & VM_ALLOC_NODUMP) != 0 ? PG_NODUMP : 0) |
+ ((req & VM_ALLOC_NOFREE) != 0 ? PG_NOFREE : 0);
vmd = VM_DOMAIN(domain);
again:
if (vmd->vmd_pgcache[VM_FREEPOOL_DIRECT].zone != NULL) {
@@ -3937,6 +3942,8 @@ vm_page_free_prep(vm_page_t m)
m, i, (uintmax_t)*p));
}
#endif
+ KASSERT((m->flags & PG_NOFREE) == 0,
+ ("%s: attempting to free a PG_NOFREE page", __func__));
if ((m->oflags & VPO_UNMANAGED) == 0) {
KASSERT(!pmap_page_is_mapped(m),
("vm_page_free_prep: freeing mapped page %p", m));
diff --git a/sys/vm/vm_page.h b/sys/vm/vm_page.h
index 61a0228273c2..07a6c98c8ee8 100644
--- a/sys/vm/vm_page.h
+++ b/sys/vm/vm_page.h
@@ -457,6 +457,7 @@ extern struct mtx_padalign pa_lock[];
#define PG_ZERO 0x04 /* page is zeroed */
#define PG_MARKER 0x08 /* special queue marker page */
#define PG_NODUMP 0x10 /* don't include this page in a
dump */
+#define PG_NOFREE 0x20 /* page should never be freed.
*/
/*
* Misc constants.
@@ -537,7 +538,7 @@ vm_page_t PHYS_TO_VM_PAGE(vm_paddr_t pa);
#define VM_ALLOC_WIRED 0x0020 /* (acgnp) Allocate a wired
page */
#define VM_ALLOC_ZERO 0x0040 /* (acgnp) Allocate a zeroed
page */
#define VM_ALLOC_NORECLAIM 0x0080 /* (c) Do not reclaim after
failure */
-#define VM_ALLOC_AVAIL0 0x0100
+#define VM_ALLOC_NOFREE 0x0100 /* (an) Page will never be
released */
#define VM_ALLOC_NOBUSY 0x0200 /* (acgp) Do not excl busy the
page */
#define VM_ALLOC_NOCREAT 0x0400 /* (gp) Don't create a page */
#define VM_ALLOC_AVAIL1 0x0800
@@ -575,6 +576,8 @@ malloc2vm_flags(int malloc_flags)
pflags |= VM_ALLOC_WAITOK;
if ((malloc_flags & M_NORECLAIM))
pflags |= VM_ALLOC_NORECLAIM;
+ if ((malloc_flags & M_NEVERFREED))
+ pflags |= VM_ALLOC_NOFREE;
return (pflags);
}
#endif
