The branch main has been updated by kib:
URL:
https://cgit.FreeBSD.org/src/commit/?id=1aa249c935884d4c0c096c00facbb22f214128cc
commit 1aa249c935884d4c0c096c00facbb22f214128cc
Author: Konstantin Belousov <k...@freebsd.org>
AuthorDate: 2021-11-29 16:30:09 +0000
Commit: Konstantin Belousov <k...@freebsd.org>
CommitDate: 2021-12-04 22:20:58 +0000
swapoff(8): add -f flag
to force swapout by ignoring the heuristic that calculates amount of
allocated memory against total of RAM plus remaining swap.
Reviewed by: markj
Discussed with: alc
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D33165
---
sbin/swapon/swapon.8 | 16 +++++++++++-----
sbin/swapon/swapon.c | 23 ++++++++++++++++++-----
2 files changed, 29 insertions(+), 10 deletions(-)
diff --git a/sbin/swapon/swapon.8 b/sbin/swapon/swapon.8
index 7ae28031dc1e..0146a7750e12 100644
--- a/sbin/swapon/swapon.8
+++ b/sbin/swapon/swapon.8
@@ -28,7 +28,7 @@
.\" @(#)swapon.8 8.1 (Berkeley) 6/5/93
.\" $FreeBSD$
.\"
-.Dd May 19, 2020
+.Dd November 29, 2021
.Dt SWAPON 8
.Os
.Sh NAME
@@ -42,9 +42,9 @@
.Nm swapoff
.Oo Fl F Ar fstab
.Oc
-.Fl aLq | Ar
+.Fl afLq | Ar
.Nm swapctl
-.Op Fl AghklmsU
+.Op Fl AfghklmsU
.Oo
.Fl a Ar
|
@@ -125,8 +125,14 @@ informational messages will not be
written to standard output when a swap device is removed.
Note that
.Nm swapoff
-will fail and refuse to remove a swap device if there is insufficient
-VM (memory + remaining swap devices) to run the system.
+will fail and refuse to remove a swap device if a very conservative
+check does not conclude that there is sufficient VM (memory +
+remaining swap devices) to run the system.
+The
+.Fl f
+option turns off this check, which could deadlock the system
+if there is insufficient swap space remaining.
+.Pp
The
.Nm swapoff
utility
diff --git a/sbin/swapon/swapon.c b/sbin/swapon/swapon.c
index 5adc870adf59..d644d99e7913 100644
--- a/sbin/swapon/swapon.c
+++ b/sbin/swapon/swapon.c
@@ -51,6 +51,7 @@ __FBSDID("$FreeBSD$");
#include <sys/sysctl.h>
#include <sys/wait.h>
#include <vm/vm_param.h>
+#include <vm/swap_pager.h>
#include <err.h>
#include <errno.h>
@@ -78,7 +79,7 @@ static int run_cmd(int *, const char *, ...) __printflike(2,
3);
static enum { SWAPON, SWAPOFF, SWAPCTL } orig_prog, which_prog = SWAPCTL;
-static int Eflag, qflag;
+static int Eflag, fflag, qflag;
int
main(int argc, char **argv)
@@ -101,7 +102,7 @@ main(int argc, char **argv)
doall = 0;
etc_fstab = NULL;
- while ((ch = getopt(argc, argv, "AadEghklLmqsUF:")) != -1) {
+ while ((ch = getopt(argc, argv, "AadEfghklLmqsUF:")) != -1) {
switch(ch) {
case 'A':
if (which_prog == SWAPCTL) {
@@ -128,6 +129,12 @@ main(int argc, char **argv)
else
usage();
break;
+ case 'f':
+ if (which_prog == SWAPOFF)
+ fflag = 1;
+ else
+ usage();
+ break;
case 'g':
hflag = 'G';
break;
@@ -782,12 +789,18 @@ swapon_trim(const char *name)
static const char *
swap_on_off_sfile(const char *name, int doingall)
{
+ struct swapoff_new_args sa;
int error;
if (which_prog == SWAPON)
error = Eflag ? swapon_trim(name) : swapon(name);
- else /* SWAPOFF */
- error = swapoff(name);
+ else { /* SWAPOFF */
+ bzero(&sa, sizeof(sa));
+ sa.name = name;
+ if (fflag)
+ sa.flags |= SWAPOFF_FORCE;
+ error = swapoff((const char *)&sa);
+ }
if (error == -1) {
switch (errno) {
@@ -820,7 +833,7 @@ usage(void)
fprintf(stderr, "[-F fstab] -aLq | [-E] file ...\n");
break;
case SWAPOFF:
- fprintf(stderr, "[-F fstab] -aLq | file ...\n");
+ fprintf(stderr, "[-F fstab] -afLq | file ...\n");
break;
case SWAPCTL:
fprintf(stderr, "[-AghklmsU] [-a file ... | -d file ...]\n");
