git: 42812ccc969f - main - Add vm.swap_objects sysctl

The branch main has been updated by kib:

URL: https://cgit.FreeBSD.org/src/commit/?id=42812ccc969f174b3e5827c1c320b1738a1e0985

commit 42812ccc969f174b3e5827c1c320b1738a1e0985
Author:     Konstantin Belousov <kib@FreeBSD.org>
AuthorDate: 2021-07-13 10:27:36 +0000
Commit:     Konstantin Belousov <kib@FreeBSD.org>
CommitDate: 2021-10-25 17:34:01 +0000

    Add vm.swap_objects sysctl
    
    Reviewed by:    markj
    Sponsored by:   The FreeBSD Foundation
    MFC after:      1 week
    Differential revision:  https://reviews.freebsd.org/D31163
---
 sys/vm/vm_object.c | 28 ++++++++++++++++++++++++----
 1 file changed, 24 insertions(+), 4 deletions(-)

diff --git a/sys/vm/vm_object.c b/sys/vm/vm_object.c
index 533d1e37318e..addcf5f2c686 100644
--- a/sys/vm/vm_object.c
+++ b/sys/vm/vm_object.c
@@ -2471,7 +2471,7 @@ vm_object_busy_wait(vm_object_t obj, const char *wmesg)
 }
 
 static int
-vm_object_list_handler(struct sysctl_req *req)
+vm_object_list_handler(struct sysctl_req *req, bool swap_only)
 {
 	struct kinfo_vmobject *kvo;
 	char *fullpath, *freepath;
@@ -2509,10 +2509,12 @@ vm_object_list_handler(struct sysctl_req *req)
 	 */
 	mtx_lock(&vm_object_list_mtx);
 	TAILQ_FOREACH(obj, &vm_object_list, object_list) {
-		if (obj->type == OBJT_DEAD)
+		if (obj->type == OBJT_DEAD ||
+		    (swap_only && (obj->flags & (OBJ_ANON | OBJ_SWAP)) == 0))
 			continue;
 		VM_OBJECT_RLOCK(obj);
-		if (obj->type == OBJT_DEAD) {
+		if (obj->type == OBJT_DEAD ||
+		    (swap_only && (obj->flags & (OBJ_ANON | OBJ_SWAP)) == 0)) {
 			VM_OBJECT_RUNLOCK(obj);
 			continue;
 		}
@@ -2592,13 +2594,31 @@ vm_object_list_handler(struct sysctl_req *req)
 static int
 sysctl_vm_object_list(SYSCTL_HANDLER_ARGS)
 {
-	return (vm_object_list_handler(req));
+	return (vm_object_list_handler(req, false));
 }
 
 SYSCTL_PROC(_vm, OID_AUTO, objects, CTLTYPE_STRUCT | CTLFLAG_RW | CTLFLAG_SKIP |
     CTLFLAG_MPSAFE, NULL, 0, sysctl_vm_object_list, "S,kinfo_vmobject",
     "List of VM objects");
 
+static int
+sysctl_vm_object_list_swap(SYSCTL_HANDLER_ARGS)
+{
+	return (vm_object_list_handler(req, true));
+}
+
+/*
+ * This sysctl returns list of the anonymous or swap objects. Intent
+ * is to provide stripped optimized list useful to analyze swap use.
+ * Since technically non-swap (default) objects participate in the
+ * shadow chains, and are converted to swap type as needed by swap
+ * pager, we must report them.
+ */
+SYSCTL_PROC(_vm, OID_AUTO, swap_objects,
+    CTLTYPE_STRUCT | CTLFLAG_RW | CTLFLAG_SKIP | CTLFLAG_MPSAFE, NULL, 0,
+    sysctl_vm_object_list_swap, "S,kinfo_vmobject",
+    "List of swap VM objects");
+
 #include "opt_ddb.h"
 #ifdef DDB
 #include <sys/kernel.h>