forked from pool/systemd
76 lines
2.7 KiB
Diff
76 lines
2.7 KiB
Diff
|
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:
|