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systemd/0006-sd-event-initialization-perturbation-value-right-bef.patch

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From 52444dc478fe38b5b69a771923ab429a41927aa5 Mon Sep 17 00:00:00 2001
From: Lennart Poettering <lennart@poettering.net>
Date: Mon, 24 Mar 2014 23:54:21 +0100
Subject: [PATCH] sd-event: initialization perturbation value right before we
use it
That way, we don't forget to initialize it when the watchdog is
initialized before all event sources.
---
src/libsystemd/sd-event/sd-event.c | 34 +++++++++++++++++++++-------------
1 file changed, 21 insertions(+), 13 deletions(-)
--- src/libsystemd/sd-event/sd-event.c
+++ src/libsystemd/sd-event/sd-event.c 2014-03-28 12:44:05.652327044 +0000
@@ -648,13 +648,31 @@ _public_ int sd_event_add_io(
return 0;
}
+static void initialize_perturb(sd_event *e) {
+ sd_id128_t bootid = {};
+
+ /* When we sleep for longer, we try to realign the wakeup to
+ the same time wihtin each minute/second/250ms, so that
+ events all across the system can be coalesced into a single
+ CPU wakeup. However, let's take some system-specific
+ randomness for this value, so that in a network of systems
+ with synced clocks timer events are distributed a
+ bit. Here, we calculate a perturbation usec offset from the
+ boot ID. */
+
+ if (_likely_(e->perturb != (usec_t) -1))
+ return;
+
+ if (sd_id128_get_boot(&bootid) >= 0)
+ e->perturb = (bootid.qwords[0] ^ bootid.qwords[1]) % USEC_PER_MINUTE;
+}
+
static int event_setup_timer_fd(
sd_event *e,
EventSourceType type,
int *timer_fd,
clockid_t id) {
- sd_id128_t bootid = {};
struct epoll_event ev = {};
int r, fd;
@@ -677,18 +695,6 @@ static int event_setup_timer_fd(
return -errno;
}
- /* When we sleep for longer, we try to realign the wakeup to
- the same time wihtin each minute/second/250ms, so that
- events all across the system can be coalesced into a single
- CPU wakeup. However, let's take some system-specific
- randomness for this value, so that in a network of systems
- with synced clocks timer events are distributed a
- bit. Here, we calculate a perturbation usec offset from the
- boot ID. */
-
- if (sd_id128_get_boot(&bootid) >= 0)
- e->perturb = (bootid.qwords[0] ^ bootid.qwords[1]) % USEC_PER_MINUTE;
-
*timer_fd = fd;
return 0;
}
@@ -1506,6 +1512,8 @@ static usec_t sleep_between(sd_event *e,
if (b <= a + 1)
return a;
+ initialize_perturb(e);
+
/*
Find a good time to wake up again between times a and b. We
have two goals here: