sleep: introduce SuspendEstimationSec=

Before v252, HibernateDelaySec= specifies the maximum timespan that the
system in suspend state, and the system hibernate after the timespan.

However, after 96d662fa4c8cab24da57523c5e49e6ef3967fc13, the setting is
repurposed as the default interval to measure battery charge level and
estimate the battery discharging late. And if the system has enough
battery capacity, then the system will stay in suspend state and not
hibernate even if the time passed. See issue #25269.

To keep the backward compatibility, let's introduce another setting
SuspendEstimationSec= for controlling the interval to measure
battery charge level, and make HibernateDelaySec= work as of v251.

This also drops implementation details from the man page.

Fixes #25269.

diff --git a/man/systemd-sleep.conf.xml b/man/systemd-sleep.conf.xml
index be04f2cdf1e0bad5f2618f41f9fba5cfa0bb7a49..79ebef1fefc01f1e03118e204a6636d3bb77cb7b 100644 (file)
--- a/man/systemd-sleep.conf.xml
+++ b/man/systemd-sleep.conf.xml
@@ -77,29 +77,16 @@
       <varlistentry>
         <term>suspend-then-hibernate</term>
 
-        <listitem><para>A low power state where initially user.slice unit is freezed.
-        If the hardware supports low-battery alarms (ACPI _BTP), then the system is
-        first suspended (the state is stored in RAM) and then hibernates if the system
-        is woken up by the hardware via ACPI low-battery signal. Unit user.slice is
-        thawed when system returns from hibernation. If the hardware does not support
-        low-battery alarms (ACPI _BTP), then the system is suspended based on battery's
-        current percentage capacity. If the current battery capacity is higher than 5%, the
-        system suspends for interval calculated using battery discharge rate per hour or
-        <command>HibernateDelaySec=</command>
-        if former is not available.
-        Battery discharge rate per hour is stored in a file which is created after
-        initial suspend-resume cycle. The value is calculated using battery decreasing
-        charge level over a timespan for which system was suspended. For each battery
-        connected to the system, there is a unique entry. After RTC alarm wakeup from
-        suspend, battery discharge rate per hour is again estimated. If the current battery
-        charge level is equal to or less than 5%, the system will be hibernated (the state
-        is then stored on disk) else the system goes back to suspend for the interval
-        calculated using battery discharge rate per hour.
-        In case of manual wakeup, if the battery was discharged while the system was
-        suspended, the battery discharge rate is estimated and stored on the filesystem.
-        In case the system is woken up by the hardware via the ACPI low-battery signal,
-        then it hibernates.
-        </para></listitem>
+        <listitem>
+          <para>A low power state where the system is initially suspended (the state is stored in
+          RAM). If the system supports low-battery alarms (ACPI _BTP), then the system will be woken up by
+          the ACPI low-battery signal and hibernated (the state is then stored on disk). Also, if not
+          interrupted within the timespan specified by <varname>HibernateDelaySec=</varname> or the estimated
+          timespan until the system battery charge level goes down to 5%, then the system will be woken up by the
+          RTC alarm and hibernated. The estimated timespan is calculated from the change of the battery
+          capacity level after the time specified by <varname>SuspendEstimationSec=</varname> or when
+          the system is woken up from the suspend.</para>
+        </listitem>
       </varlistentry>
 
     </variablelist>
@@ -189,13 +176,28 @@
         uses the value of <varname>SuspendState=</varname> when suspending and the value of <varname>HibernateState=</varname> when hibernating.
         </para></listitem>
       </varlistentry>
+
       <varlistentry>
         <term><varname>HibernateDelaySec=</varname></term>
-        <listitem><para>The amount of time the system spends in suspend mode
-        before the RTC alarm wakes the system, before the battery discharge rate
-        can be estimated and used instead to calculate the suspension interval.
-        <citerefentry><refentrytitle>systemd-suspend-then-hibernate.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>. Defaults
-        to 2h.</para></listitem>
+
+        <listitem>
+          <para>The amount of time the system spends in suspend mode before the system is
+          automatically put into hibernate mode. Only used by
+          <citerefentry><refentrytitle>systemd-suspend-then-hibernate.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
+          If the system has a battery, then defaults to the estimated timespan until the system battery charge level goes down to 5%.
+          If the system has no battery, then defaults to 2h.</para>
+        </listitem>
+      </varlistentry>
+
+      <varlistentry>
+        <term><varname>SuspendEstimationSec=</varname></term>
+
+        <listitem>
+          <para>The RTC alarm will wake the system after the specified timespan to measure the system battery
+          capacity level and estimate battery discharging rate, which is used for estimating timespan until the system battery charge
+          level goes down to 5%. Only used by
+          <citerefentry><refentrytitle>systemd-suspend-then-hibernate.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
+          Defaults to 2h.</para></listitem>
       </varlistentry>
     </variablelist>
   </refsect1>

diff --git a/src/shared/sleep-config.c b/src/shared/sleep-config.c
index 260e8ccca48d6b1e91e4dc924f0ad255c6d3ba47..45b78bdafa23cc98a4bc636d3b582647d31ebc7e 100644 (file)
--- a/src/shared/sleep-config.c
+++ b/src/shared/sleep-config.c
@@ -65,10 +65,14 @@ int parse_sleep_config(SleepConfig **ret_sleep_config) {
         int allow_suspend = -1, allow_hibernate = -1,
             allow_s2h = -1, allow_hybrid_sleep = -1;
 
-        sc = new0(SleepConfig, 1);
+        sc = new(SleepConfig, 1);
         if (!sc)
                 return log_oom();
 
+        *sc = (SleepConfig) {
+                .hibernate_delay_usec = USEC_INFINITY,
+        };
+
         const ConfigTableItem items[] = {
                 { "Sleep", "AllowSuspend",              config_parse_tristate, 0, &allow_suspend                  },
                 { "Sleep", "AllowHibernation",          config_parse_tristate, 0, &allow_hibernate                },
@@ -83,6 +87,7 @@ int parse_sleep_config(SleepConfig **ret_sleep_config) {
                 { "Sleep", "HybridSleepState",          config_parse_strv,     0, sc->states + SLEEP_HYBRID_SLEEP },
 
                 { "Sleep", "HibernateDelaySec",         config_parse_sec,      0, &sc->hibernate_delay_usec       },
+                { "Sleep", "SuspendEstimationSec",      config_parse_sec,      0, &sc->suspend_estimation_usec    },
                 {}
         };
 
@@ -113,8 +118,8 @@ int parse_sleep_config(SleepConfig **ret_sleep_config) {
                 sc->modes[SLEEP_HYBRID_SLEEP] = strv_new("suspend", "platform", "shutdown");
         if (!sc->states[SLEEP_HYBRID_SLEEP])
                 sc->states[SLEEP_HYBRID_SLEEP] = strv_new("disk");
-        if (sc->hibernate_delay_usec == 0)
-                sc->hibernate_delay_usec = 2 * USEC_PER_HOUR;
+        if (sc->suspend_estimation_usec == 0)
+                sc->suspend_estimation_usec = DEFAULT_SUSPEND_ESTIMATION_USEC;
 
         /* Ensure values set for all required fields */
         if (!sc->states[SLEEP_SUSPEND] || !sc->modes[SLEEP_HIBERNATE]

diff --git a/src/shared/sleep-config.h b/src/shared/sleep-config.h
index 813f33c7c0662edc5a89a1c83ca1b9ee192c4a4a..99423fe3d37b91c81500720bc6189c72469b7eb1 100644 (file)
--- a/src/shared/sleep-config.h
+++ b/src/shared/sleep-config.h
@@ -6,6 +6,8 @@
 #include "hashmap.h"
 #include "time-util.h"
 
+#define DEFAULT_SUSPEND_ESTIMATION_USEC (1 * USEC_PER_HOUR)
+
 typedef enum SleepOperation {
         SLEEP_SUSPEND,
         SLEEP_HIBERNATE,
@@ -20,6 +22,7 @@ typedef struct SleepConfig {
         char **modes[_SLEEP_OPERATION_MAX];
         char **states[_SLEEP_OPERATION_MAX];
         usec_t hibernate_delay_usec;
+        usec_t suspend_estimation_usec;
 } SleepConfig;
 
 SleepConfig* free_sleep_config(SleepConfig *sc);

diff --git a/src/sleep/sleep.c b/src/sleep/sleep.c
index d1c45e264d7cf6edc5d2674a65c1a9e33698b8c2..0611cfb7809cbfb298b3154adedb6ae466d0ec92 100644 (file)
--- a/src/sleep/sleep.c
+++ b/src/sleep/sleep.c
@@ -267,10 +267,13 @@ static int execute(
 }
 
 static int custom_timer_suspend(const SleepConfig *sleep_config) {
+        usec_t hibernate_timestamp;
         int r;
 
         assert(sleep_config);
 
+        hibernate_timestamp = usec_add(now(CLOCK_BOOTTIME), sleep_config->hibernate_delay_usec);
+
         while (battery_is_low() == 0) {
                 _cleanup_hashmap_free_ Hashmap *last_capacity = NULL, *current_capacity = NULL;
                 _cleanup_close_ int tfd = -EBADF;
@@ -287,14 +290,25 @@ static int custom_timer_suspend(const SleepConfig *sleep_config) {
                 if (r < 0)
                         return log_error_errno(r, "Error fetching battery capacity percentage: %m");
 
-                r = get_total_suspend_interval(last_capacity, &suspend_interval);
-                if (r < 0) {
-                        log_debug_errno(r, "Failed to estimate suspend interval using previous discharge rate, ignoring: %m");
-                        /* In case of no battery or any errors, system suspend interval will be set to HibernateDelaySec=. */
-                        suspend_interval = sleep_config->hibernate_delay_usec;
+                if (hashmap_isempty(last_capacity))
+                        /* In case of no battery, system suspend interval will be set to HibernateDelaySec= or 2 hours. */
+                        suspend_interval = timestamp_is_set(hibernate_timestamp) ? sleep_config->hibernate_delay_usec : DEFAULT_SUSPEND_ESTIMATION_USEC;
+                else {
+                        r = get_total_suspend_interval(last_capacity, &suspend_interval);
+                        if (r < 0) {
+                                log_debug_errno(r, "Failed to estimate suspend interval using previous discharge rate, ignoring: %m");
+                                /* In case of any errors, especially when we do not know the battery
+                                 * discharging rate, system suspend interval will be set to
+                                 * SuspendEstimationSec=. */
+                                suspend_interval = sleep_config->suspend_estimation_usec;
+                        }
                 }
 
+                /* Do not suspend more than HibernateDelaySec= */
                 usec_t before_timestamp = now(CLOCK_BOOTTIME);
+                suspend_interval = MIN(suspend_interval, usec_sub_unsigned(hibernate_timestamp, before_timestamp));
+                if (suspend_interval <= 0)
+                        break; /* system should hibernate */
 
                 log_debug("Set timerfd wake alarm for %s", FORMAT_TIMESPAN(suspend_interval, USEC_PER_SEC));
                 /* Wake alarm for system with or without battery to hibernate or estimate discharge rate whichever is applicable */
@@ -380,7 +394,7 @@ static int freeze_thaw_user_slice(const char **method) {
 
 static int execute_s2h(const SleepConfig *sleep_config) {
         _unused_ _cleanup_(freeze_thaw_user_slice) const char *auto_method_thaw = "ThawUnit";
-        int r, k;
+        int r;
 
         assert(sleep_config);
 
@@ -388,15 +402,21 @@ static int execute_s2h(const SleepConfig *sleep_config) {
         if (r < 0)
                 log_debug_errno(r, "Failed to freeze unit user.slice, ignoring: %m");
 
-        r = check_wakeup_type();
-        if (r < 0)
-                log_debug_errno(r, "Failed to check hardware wakeup type, ignoring: %m");
-
-        k = battery_trip_point_alarm_exists();
-        if (k < 0)
-                log_debug_errno(k, "Failed to check whether acpi_btp support is enabled or not, ignoring: %m");
+        /* Only check if we have automated battery alarms if HibernateDelaySec= is not set, as in that case
+         * we'll busy poll for the configured interval instead */
+        if (!timestamp_is_set(sleep_config->hibernate_delay_usec)) {
+                r = check_wakeup_type();
+                if (r < 0)
+                        log_debug_errno(r, "Failed to check hardware wakeup type, ignoring: %m");
+                else {
+                        r = battery_trip_point_alarm_exists();
+                        if (r < 0)
+                                log_debug_errno(r, "Failed to check whether acpi_btp support is enabled or not, ignoring: %m");
+                }
+        } else
+                r = 0;  /* Force fallback path */
 
-        if (r >= 0 && k > 0) {
+        if (r > 0) { /* If we have both wakeup alarms and battery trip point support, use them */
                 log_debug("Attempting to suspend...");
                 r = execute(sleep_config, SLEEP_SUSPEND, NULL);
                 if (r < 0)

diff --git a/src/sleep/sleep.conf b/src/sleep/sleep.conf
index a3d31140d8b573a8e3f93092ba9f640548e35341..4c8e8b9680bc42e85d36d2c91b83da1f1e862409 100644 (file)
--- a/src/sleep/sleep.conf
+++ b/src/sleep/sleep.conf
@@ -23,4 +23,5 @@
 #HibernateState=disk
 #HybridSleepMode=suspend platform shutdown
 #HybridSleepState=disk
-#HibernateDelaySec=120min
+#HibernateDelaySec=
+#SuspendEstimationSec=60min