From bdbc98abb3aa323f6323b11db39c740e6f8fc5b1 Mon Sep 17 00:00:00 2001 From: Rainer Fiebig Date: Fri, 22 Dec 2017 11:13:59 +0100 Subject: PM: hibernate: Do not subtract NR_FILE_MAPPED in minimum_image_size() s2disk/s2both may fail unnecessarily and erratically if NR_FILE_MAPPED is high - for instance when using VMs with VirtualBox and perhaps VMware Player. In those situations s2disk becomes unreliable and therefore unusable. A typical scenario is: user issues a s2disk and it fails. User issues a second s2disk immediately after that and it succeeds. And user wonders why. The problem is caused by minimum_image_size() in snapshot.c. The value it returns is roughly 100% too high because NR_FILE_MAPPED is subtracted in its calculation. Eventually the number of preallocated image pages is falsely too low. This doesn't matter as long as NR_FILE_MAPPED-values are in a normal range or in 32bit-environments as the code allows for allocation of additional pages from highmem. But with the high values generated by VirtualBox-VMs (a 2-GB-VM causes NR_FILE_MAPPED go up by 2 GB) it may lead to failure in 64bit-systems. Not subtracting NR_FILE_MAPPED in minimum_image_size() solves the problem. I've done at least hundreds of successful s2both/s2disk now on an x86_64 system (with and without VirtualBox) which gives me some confidence that this is right. It has turned s2disk/s2both from unusable into 100% reliable. Link: https://bugzilla.kernel.org/show_bug.cgi?id=97201 Signed-off-by: Rainer Fiebig Signed-off-by: Rafael J. Wysocki --- kernel/power/snapshot.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) (limited to 'kernel') diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c index bce0464524d8..3d37c279c090 100644 --- a/kernel/power/snapshot.c +++ b/kernel/power/snapshot.c @@ -1645,8 +1645,7 @@ static unsigned long free_unnecessary_pages(void) * [number of saveable pages] - [number of pages that can be freed in theory] * * where the second term is the sum of (1) reclaimable slab pages, (2) active - * and (3) inactive anonymous pages, (4) active and (5) inactive file pages, - * minus mapped file pages. + * and (3) inactive anonymous pages, (4) active and (5) inactive file pages. */ static unsigned long minimum_image_size(unsigned long saveable) { @@ -1656,8 +1655,7 @@ static unsigned long minimum_image_size(unsigned long saveable) + global_node_page_state(NR_ACTIVE_ANON) + global_node_page_state(NR_INACTIVE_ANON) + global_node_page_state(NR_ACTIVE_FILE) - + global_node_page_state(NR_INACTIVE_FILE) - - global_node_page_state(NR_FILE_MAPPED); + + global_node_page_state(NR_INACTIVE_FILE); return saveable <= size ? 0 : saveable - size; } -- cgit v1.2.3 From 4bf236a3330e97d275e5848420f7e31948fef07a Mon Sep 17 00:00:00 2001 From: Bart Van Assche Date: Fri, 5 Jan 2018 09:19:08 -0800 Subject: PM / sleep: Make lock/unlock_system_sleep() available to kernel modules Since pm_mutex is not exported using lock/unlock_system_sleep() from inside a kernel module causes a "pm_mutex undefined" linker error. Hence move lock/unlock_system_sleep() into kernel/power/main.c and export these. Signed-off-by: Bart Van Assche Signed-off-by: Rafael J. Wysocki --- kernel/power/main.c | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) (limited to 'kernel') diff --git a/kernel/power/main.c b/kernel/power/main.c index 3a2ca9066583..705c2366dafe 100644 --- a/kernel/power/main.c +++ b/kernel/power/main.c @@ -22,6 +22,35 @@ DEFINE_MUTEX(pm_mutex); #ifdef CONFIG_PM_SLEEP +void lock_system_sleep(void) +{ + current->flags |= PF_FREEZER_SKIP; + mutex_lock(&pm_mutex); +} +EXPORT_SYMBOL_GPL(lock_system_sleep); + +void unlock_system_sleep(void) +{ + /* + * Don't use freezer_count() because we don't want the call to + * try_to_freeze() here. + * + * Reason: + * Fundamentally, we just don't need it, because freezing condition + * doesn't come into effect until we release the pm_mutex lock, + * since the freezer always works with pm_mutex held. + * + * More importantly, in the case of hibernation, + * unlock_system_sleep() gets called in snapshot_read() and + * snapshot_write() when the freezing condition is still in effect. + * Which means, if we use try_to_freeze() here, it would make them + * enter the refrigerator, thus causing hibernation to lockup. + */ + current->flags &= ~PF_FREEZER_SKIP; + mutex_unlock(&pm_mutex); +} +EXPORT_SYMBOL_GPL(unlock_system_sleep); + /* Routines for PM-transition notifications */ static BLOCKING_NOTIFIER_HEAD(pm_chain_head); -- cgit v1.2.3 From 8ffdfe35b8a67e509dee5719807b7f88ed2cda7e Mon Sep 17 00:00:00 2001 From: Kyungsik Lee Date: Tue, 16 Jan 2018 10:19:43 +0900 Subject: PM / hibernate: Drop unused parameter of enough_swap Parameter flags is no longer used, remove it. Signed-off-by: Kyungsik Lee Signed-off-by: Rafael J. Wysocki --- kernel/power/swap.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/power/swap.c b/kernel/power/swap.c index 293ead59eccc..a46be1261c09 100644 --- a/kernel/power/swap.c +++ b/kernel/power/swap.c @@ -879,7 +879,7 @@ out_clean: * space avaiable from the resume partition. */ -static int enough_swap(unsigned int nr_pages, unsigned int flags) +static int enough_swap(unsigned int nr_pages) { unsigned int free_swap = count_swap_pages(root_swap, 1); unsigned int required; @@ -915,7 +915,7 @@ int swsusp_write(unsigned int flags) return error; } if (flags & SF_NOCOMPRESS_MODE) { - if (!enough_swap(pages, flags)) { + if (!enough_swap(pages)) { pr_err("Not enough free swap\n"); error = -ENOSPC; goto out_finish; -- cgit v1.2.3