svn commit: r362189 - stable/12/sys/compat/linux

[Mark Johnston]

Author: markj
Date: Mon Jun 15 03:02:59 2020
New Revision: 362189
URL: https://svnweb.freebsd.org/changeset/base/362189

Log:
  MFC r361945, r362036:
  Stop computing a "sharedram" value when emulating Linux sysinfo(2).

Modified:
  stable/12/sys/compat/linux/linux_misc.c
Directory Properties:
  stable/12/   (props changed)

Modified: stable/12/sys/compat/linux/linux_misc.c
==============================================================================
--- stable/12/sys/compat/linux/linux_misc.c	Mon Jun 15 03:02:19 2020	(r362188)
+++ stable/12/sys/compat/linux/linux_misc.c	Mon Jun 15 03:02:59 2020	(r362189)
@@ -78,7 +78,6 @@ __FBSDID("$FreeBSD$");
 #include <vm/vm_kern.h>
 #include <vm/vm_map.h>
 #include <vm/vm_extern.h>
-#include <vm/vm_object.h>
 #include <vm/swap_pager.h>
 
 #ifdef COMPAT_LINUX32
@@ -150,7 +149,6 @@ int
 linux_sysinfo(struct thread *td, struct linux_sysinfo_args *args)
 {
 	struct l_sysinfo sysinfo;
-	vm_object_t object;
 	int i, j;
 	struct timespec ts;
 
@@ -168,14 +166,13 @@ linux_sysinfo(struct thread *td, struct linux_sysinfo_
 	sysinfo.totalram = physmem * PAGE_SIZE;
 	sysinfo.freeram = sysinfo.totalram - vm_wire_count() * PAGE_SIZE;
 
+	/*
+	 * sharedram counts pages allocated to named, swap-backed objects such
+	 * as shared memory segments and tmpfs files.  There is no cheap way to
+	 * compute this, so just leave the field unpopulated.  Linux itself only
+	 * started setting this field in the 3.x timeframe.
+	 */
 	sysinfo.sharedram = 0;
-	mtx_lock(&vm_object_list_mtx);
-	TAILQ_FOREACH(object, &vm_object_list, object_list)
-		if (object->shadow_count > 1)
-			sysinfo.sharedram += object->resident_page_count;
-	mtx_unlock(&vm_object_list_mtx);
-
-	sysinfo.sharedram *= PAGE_SIZE;
 	sysinfo.bufferram = 0;
 
 	swap_pager_status(&i, &j);