1#!/bin/ksh -p
2
3#
4# This file and its contents are supplied under the terms of the
5# Common Development and Distribution License ("CDDL"), version 1.0.
6# You may only use this file in accordance with the terms of version
7# 1.0 of the CDDL.
8#
9# A full copy of the text of the CDDL should have accompanied this
10# source.  A copy of the CDDL is also available via the Internet at
11# http://www.illumos.org/license/CDDL.
12#
13
14#
15# Copyright (c) 2015, 2016 by Delphix. All rights reserved.
16#
17
18. $STF_SUITE/include/libtest.shlib
19
20#
21# DESCRIPTION:
22# msync()s of mmap()'ed file should complete quickly during
23# background dirty page writebacks by the kernel.
24#
25
26function cleanup
27{
28	log_must eval "echo $saved_vm_dirty_expire_centisecs > /proc/sys/vm/dirty_expire_centisecs"
29	log_must eval "echo $saved_vm_dirty_background_ratio > /proc/sys/vm/dirty_background_ratio"
30	log_must eval "echo $saved_vm_dirty_writeback_centisecs > /proc/sys/vm/dirty_writeback_centisecs"
31
32	# revert to some sensible defaults if the values we saved
33	# were incorrect due to a previous run being interrupted
34	if [ $(</proc/sys/vm/dirty_expire_centisecs) -eq 1 ]; then
35		log_must eval "echo 3000 > /proc/sys/vm/dirty_expire_centisecs"
36	fi
37
38	if [ $(</proc/sys/vm/dirty_background_ratio) -eq 0 ]; then
39		log_must eval "echo 10 > /proc/sys/vm/dirty_background_ratio"
40	fi
41
42	if [ $(</proc/sys/vm/dirty_writeback_centisecs) -eq 1 ]; then
43		log_must eval "echo 500 > /proc/sys/vm/dirty_writeback_centisecs"
44	fi
45}
46
47if ! is_linux; then
48	log_unsupported "Only supported on Linux, requires /proc/sys/vm/ tunables"
49fi
50
51log_onexit cleanup
52log_assert "Run the tests for mmap_sync"
53
54read -r saved_vm_dirty_expire_centisecs < /proc/sys/vm/dirty_expire_centisecs
55read -r saved_vm_dirty_background_ratio < /proc/sys/vm/dirty_background_ratio
56read -r saved_vm_dirty_writeback_centisecs < /proc/sys/vm/dirty_writeback_centisecs
57
58log_must eval "echo 1 > /proc/sys/vm/dirty_expire_centisecs"
59log_must eval "echo 1 > /proc/sys/vm/dirty_background_bytes"
60log_must eval "echo 1 > /proc/sys/vm/dirty_writeback_centisecs"
61
62log_must mmap_sync
63log_pass "mmap_sync tests passed."
64