integ/base/systemd/centos/patches/901-sd-event-don-t-touch-fd-s-accross-forks.patch
Li Zhou ccfeeef59d systemd: Prevent excessive /proc/1/mountinfo reparsing
Backport the patches for this issue:
https://bugzilla.redhat.com/show_bug.cgi?id=1819868

We met such an issue:
When testing a large number of pods (> 230), occasionally observed a
number of issues related to systemd process:
    systemd ran continually 90-100% cpu usage
    systemd memory usage started increasing rapidly (20GB/hour)
    systemctl commands would always timeout (Failed to get properties:
        Connection timed out)
    sm services failed and can't recover: open-ldap,
        registry-token-server, docker-distribution, etcd
    new pods can't start, and got stuck in state ContainerCreating

Those patches work to prevent excessive /proc/1/mountinfo reparsing.
It has been verified that those patches can improve this performance
greatly.

16 commits are listed in sequence (from [1] to [16]) at below link
for the issue:
https://github.com/systemd-rhel/rhel-8/pull/154/commits

[16](10)core: prevent excessive /proc/self/mountinfo parsing
[15][Dropped-6]test: add ratelimiting test
[14](9)sd-event: add ability to ratelimit event sources
[13](8)sd-event: increase n_enabled_child_sources just once
[12](7)sd-event: update state at the end in event_source_enable
[11](6)sd-event: remove earliest_index/latest_index into common part of
event source objects
[10][Dropped-5]sd-event: follow coding style with naming return
parameter
[9] [Dropped-4]sd-event: ref event loop while in sd_event_prepare() ot
sd_event_run()
[8] (5)sd-event: refuse running default event loops in any other thread
than the one they are default for
[7] [Dropped-3]sd-event: let's suffix last_run/last_log with "_usec"
[6] [Dropped-2]sd-event: fix delays assert brain-o (#17790)
[5] (4)sd-event: split out code to add/remove timer event sources to
earliest/latest prioq
[4] (3)sd-event: split clock data allocation out of sd_event_add_time()
[3] [Dropped-1]sd-event: mention that two debug logged events are
ignored
[2] (2)sd-event: split out enable and disable codepaths from
sd_event_source_set_enabled()
[1] (1)sd-event: split out helper functions for reshuffling prioqs

I ported 10 of them back (from (1) to (10)) to fix this issue
and dropped the other 6 (from [Dropped-1] to [Dropped-6]) for those
reasons:
[Dropped-1]Only changes error log.
[Dropped-2]Fixes a bug introduced in a commit which doesn't exist in
this version.
[Dropped-3]Only changes vars' names and there is no functional change.
[Dropped-4]More commits are needed for merging it, while I don't see
any help on adding the rate-limiting ability.
[Dropped-5]Change coding style for a function which isn't really used
by anyone.
[Dropped-6]Add test cases.

Closes-Bug: #1924686
Signed-off-by: Li Zhou <li.zhou@windriver.com>
Change-Id: Ia4c8f162cb1a47b40d1b26cf4d604976b97e92d6
2021-04-22 22:09:33 -04:00

55 lines
1.7 KiB
Diff

From 5de71cb7d887a569bfb987efdceda493338990bf Mon Sep 17 00:00:00 2001
From: Tom Gundersen <teg@jklm.no>
Date: Thu, 4 Jun 2015 16:54:45 +0200
Subject: [PATCH 01/20] sd-event: don't touch fd's accross forks
We protect most of the API from use accross forks, but we still allow both
sd_event and sd_event_source objects to be unref'ed. This would cause
problems as it would unregister sources from the underlying eventfd, hence
also affecting the original instance in the parent process.
This fixes the issue by not touching the fds on unref when done accross a fork,
but still free the memory.
This fixes a regression introduced by
"udevd: move main-loop to sd-event": 693d371d30fee
where the worker processes were disabling the inotify event source in the
main daemon.
[commit f68067348f58cd08d8f4f5325ce22f9a9d2c2140 from
https://github.com/systemd-rhel/rhel-8/]
Signed-off-by: Li Zhou <li.zhou@windriver.com>
---
src/libsystemd/sd-event/sd-event.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/src/libsystemd/sd-event/sd-event.c b/src/libsystemd/sd-event/sd-event.c
index 9d48e5a..a84bfbb 100644
--- a/src/libsystemd/sd-event/sd-event.c
+++ b/src/libsystemd/sd-event/sd-event.c
@@ -474,6 +474,9 @@ static int source_io_unregister(sd_event_source *s) {
assert(s);
assert(s->type == SOURCE_IO);
+ if (event_pid_changed(s->event))
+ return 0;
+
if (!s->io.registered)
return 0;
@@ -604,6 +607,9 @@ static int event_update_signal_fd(sd_event *e) {
assert(e);
+ if (event_pid_changed(e))
+ return 0;
+
add_to_epoll = e->signal_fd < 0;
r = signalfd(e->signal_fd, &e->sigset, SFD_NONBLOCK|SFD_CLOEXEC);
--
2.17.1