Module Name: src
Committed By: maxv
Date: Fri Feb 21 18:31:56 UTC 2020
Modified Files:
src/sys/arch/x86/x86: pmap.c
Log Message:
Add comments.
To generate a diff of this commit:
cvs rdiff -u -r1.355 -r1.356 src/sys/arch/x86/x86/pmap.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/arch/x86/x86/pmap.c
diff -u src/sys/arch/x86/x86/pmap.c:1.355 src/sys/arch/x86/x86/pmap.c:1.356
--- src/sys/arch/x86/x86/pmap.c:1.355 Sun Jan 12 13:01:11 2020
+++ src/sys/arch/x86/x86/pmap.c Fri Feb 21 18:31:55 2020
@@ -1,4 +1,4 @@
-/* $NetBSD: pmap.c,v 1.355 2020/01/12 13:01:11 ad Exp $ */
+/* $NetBSD: pmap.c,v 1.356 2020/02/21 18:31:55 maxv Exp $ */
/*
* Copyright (c) 2008, 2010, 2016, 2017, 2019, 2020 The NetBSD Foundation, Inc.
@@ -130,7 +130,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.355 2020/01/12 13:01:11 ad Exp $");
+__KERNEL_RCSID(0, "$NetBSD: pmap.c,v 1.356 2020/02/21 18:31:55 maxv Exp $");
#include "opt_user_ldt.h"
#include "opt_lockdebug.h"
@@ -1258,6 +1258,17 @@ slotspace_rand(int type, size_t sz, size
vaddr_t startva, va;
sz = roundup(sz, align);
+
+ /*
+ * Take one more slot with +NBPD_L4, because we may end up choosing
+ * an area that crosses slots:
+ * +------+------+------+
+ * | Slot | Slot | Slot |
+ * +------+------+------+
+ * [Chosen Area]
+ * And in that case we must take into account the additional slot
+ * consumed.
+ */
nslots = roundup(sz+NBPD_L4, NBPD_L4) / NBPD_L4;
/* Get the holes. */
@@ -1279,16 +1290,20 @@ slotspace_rand(int type, size_t sz, size
minnslot = slotspace.area[i].nslot;
}
}
+
+ /* No hole anymore, stop here. */
if (minsslot == 512) {
break;
}
+ /* Register the hole. */
if (minsslot - curslot >= nslots) {
holes[nholes].start = curslot;
holes[nholes].end = minsslot;
nholes++;
}
+ /* Skip that hole, and iterate again. */
curslot = minsslot + minnslot;
}
