Re: [systemd-devel] [PATCH] Drop Before=paths/sockets/timers.target from DefaultDependencies.
On Wed, 29.01.14 19:37, Andrey Borzenkov (arvidj...@gmail.com) wrote: So, in order to understand DefaultDependencies, you need to read the related bits in systemd.unit(5), systemd.service(5), systemd.timer(5), systemd.socket(5), systemd.path(5), systemd.slice(5), systemd.swap(5) and systemd.target(5). The manpages systemd.mount(5) and systemd.automount(5) seem to lack any information about default dependencies. In theory you need just two of them - for two units in question, for which you try to understand why they have these specific relations. This is really annoying to learn - I'd suggest collecting all this information in one place - IMO, it belongs either into systemd.unit(5) or into its own manpage. Actually I think having default dependency for a unit type in the man page for this unit type is logical. May be some magic to auto-generate cross-reference man page would be nice. Maintaining this manually is too error prone. Yeah, I agree, this belongs in the individual type-specific man pages, whith maybe a longer discussion what this is about next to the generic DefaultDependencies= setting in systemd.unit(5), with hints that the precise rules are documented in the indiviudal pages... Lennart -- Lennart Poettering, Red Hat ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] [PATCH] Drop Before=paths/sockets/timers.target from DefaultDependencies.
Am 29.01.2014 03:49, schrieb Andrey Borzenkov: Zbyszek's argument for the patch, however, is that following the recommended WantedBy= behavior already applies the same Before= dependency, Where is *this* documented? Unless I misunderstand what you say. The documentation (and code) regarding the sometimes unexpected behaviour of DefaultDependencies is scattered in a few places - this cost me some time when I first learned how to systemd. From systemd.unit(5): If true, (the default), a few default dependencies will implicitly be created for the unit. The actual dependencies created depend on the unit type. Now, it is true that when you look at systemd.service(5) and friends, there is no mention of this implicit Before= dependency mentioned above. Even when you look at the code, you won't find it directly. Eventually, you'll find this bit in systemd.target(5): Unless DefaultDependencies= is set to false, target units will implicitly complement all configured dependencies of type Wants=, Requires=, RequiresOverridable= with dependencies of type After= if the units in question also have DefaultDependencies=true So, in order to understand DefaultDependencies, you need to read the related bits in systemd.unit(5), systemd.service(5), systemd.timer(5), systemd.socket(5), systemd.path(5), systemd.slice(5), systemd.swap(5) and systemd.target(5). The manpages systemd.mount(5) and systemd.automount(5) seem to lack any information about default dependencies. This is really annoying to learn - I'd suggest collecting all this information in one place - IMO, it belongs either into systemd.unit(5) or into its own manpage. signature.asc Description: OpenPGP digital signature ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] [PATCH] Drop Before=paths/sockets/timers.target from DefaultDependencies.
On Tue, 28.01.14 13:12, da...@davidstrauss.net (da...@davidstrauss.net) wrote:
From: David Strauss da...@davidstrauss.net
What's the rationale here?
Documenting what DEfaultDependencies= does is something that has been on
the todo list since a long time, we really should document this.
---
src/core/path.c | 5 -
src/core/socket.c | 4
src/core/timer.c | 4
3 files changed, 13 deletions(-)
diff --git a/src/core/path.c b/src/core/path.c
index fc7069e..95ed015 100644
--- a/src/core/path.c
+++ b/src/core/path.c
@@ -336,11 +336,6 @@ static int path_add_default_dependencies(Path *p) {
assert(p);
-r = unit_add_dependency_by_name(UNIT(p), UNIT_BEFORE,
-SPECIAL_PATHS_TARGET, NULL, true);
-if (r 0)
-return r;
-
if (UNIT(p)-manager-running_as == SYSTEMD_SYSTEM) {
r = unit_add_two_dependencies_by_name(UNIT(p), UNIT_AFTER,
UNIT_REQUIRES,
SPECIAL_SYSINIT_TARGET, NULL, true);
diff --git a/src/core/socket.c b/src/core/socket.c
index 7eac0eb..4917185 100644
--- a/src/core/socket.c
+++ b/src/core/socket.c
@@ -283,10 +283,6 @@ static int socket_add_default_dependencies(Socket *s) {
int r;
assert(s);
-r = unit_add_dependency_by_name(UNIT(s), UNIT_BEFORE,
SPECIAL_SOCKETS_TARGET, NULL, true);
-if (r 0)
-return r;
-
if (UNIT(s)-manager-running_as == SYSTEMD_SYSTEM) {
r = unit_add_two_dependencies_by_name(UNIT(s), UNIT_AFTER,
UNIT_REQUIRES, SPECIAL_SYSINIT_TARGET, NULL, true);
if (r 0)
diff --git a/src/core/timer.c b/src/core/timer.c
index a4ff662..ae7a07f 100644
--- a/src/core/timer.c
+++ b/src/core/timer.c
@@ -96,10 +96,6 @@ static int timer_add_default_dependencies(Timer *t) {
assert(t);
-r = unit_add_dependency_by_name(UNIT(t), UNIT_BEFORE,
SPECIAL_TIMERS_TARGET, NULL, true);
-if (r 0)
-return r;
-
if (UNIT(t)-manager-running_as == SYSTEMD_SYSTEM) {
r = unit_add_two_dependencies_by_name(UNIT(t), UNIT_AFTER,
UNIT_REQUIRES, SPECIAL_SYSINIT_TARGET, NULL, true);
if (r 0)
Lennart
--
Lennart Poettering, Red Hat
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Re: [systemd-devel] [PATCH] Drop Before=paths/sockets/timers.target from DefaultDependencies.
В Wed, 29 Jan 2014 10:16:06 +0100 Thomas Bächler tho...@archlinux.org пишет: Am 29.01.2014 03:49, schrieb Andrey Borzenkov: Zbyszek's argument for the patch, however, is that following the recommended WantedBy= behavior already applies the same Before= dependency, Where is *this* documented? Unless I misunderstand what you say. The documentation (and code) regarding the sometimes unexpected behaviour of DefaultDependencies is scattered in a few places - this cost me some time when I first learned how to systemd. From systemd.unit(5): If true, (the default), a few default dependencies will implicitly be created for the unit. The actual dependencies created depend on the unit type. Now, it is true that when you look at systemd.service(5) and friends, there is no mention of this implicit Before= dependency mentioned above. Even when you look at the code, you won't find it directly. Eventually, you'll find this bit in systemd.target(5): Unless DefaultDependencies= is set to false, target units will implicitly complement all configured dependencies of type Wants=, Requires=, RequiresOverridable= with dependencies of type After= if the units in question also have DefaultDependencies=true Ah! of course. Thank you. Somehow amount of documentation in systemd may also become a disadvantage :) So, in order to understand DefaultDependencies, you need to read the related bits in systemd.unit(5), systemd.service(5), systemd.timer(5), systemd.socket(5), systemd.path(5), systemd.slice(5), systemd.swap(5) and systemd.target(5). The manpages systemd.mount(5) and systemd.automount(5) seem to lack any information about default dependencies. In theory you need just two of them - for two units in question, for which you try to understand why they have these specific relations. This is really annoying to learn - I'd suggest collecting all this information in one place - IMO, it belongs either into systemd.unit(5) or into its own manpage. Actually I think having default dependency for a unit type in the man page for this unit type is logical. May be some magic to auto-generate cross-reference man page would be nice. Maintaining this manually is too error prone. signature.asc Description: PGP signature ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] [PATCH] Drop Before=paths/sockets/timers.target from DefaultDependencies.
On Wed, Jan 29, 2014 at 3:14 AM, Lennart Poettering lenn...@poettering.net wrote: What's the rationale here? Three possibilities for an *enabled* timer with DefaultDependencies=true: (1) WantedBy=timers.target, which redundantly adds Before=timers.target (because DefaultDependencies already adds it) (2) WantedBy= and After=something-later-than-timers.target (like multi-user.target), which creates a cycle systemd has to break (like Before=timers.target combined with After=multi-user.target). This is our use case, which we have because we want a timer to start at multi-user.target completing. (3) WantedBy=something-earlier-than-timers.target (like sysinit.target), which is transitively redundant because Before=basic.target is already before timers.target So, having Before=timers.target as a default dependency is either redundant or cyclical/conflicting. These same arguments are true for sockets and (probably) paths. Documenting what DEfaultDependencies= does is something that has been on the todo list since a long time, we really should document this. Yes, and documentation is an alternative that I mentioned to the patch. ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
[systemd-devel] [PATCH] Drop Before=paths/sockets/timers.target from DefaultDependencies.
From: David Strauss da...@davidstrauss.net
---
src/core/path.c | 5 -
src/core/socket.c | 4
src/core/timer.c | 4
3 files changed, 13 deletions(-)
diff --git a/src/core/path.c b/src/core/path.c
index fc7069e..95ed015 100644
--- a/src/core/path.c
+++ b/src/core/path.c
@@ -336,11 +336,6 @@ static int path_add_default_dependencies(Path *p) {
assert(p);
-r = unit_add_dependency_by_name(UNIT(p), UNIT_BEFORE,
-SPECIAL_PATHS_TARGET, NULL, true);
-if (r 0)
-return r;
-
if (UNIT(p)-manager-running_as == SYSTEMD_SYSTEM) {
r = unit_add_two_dependencies_by_name(UNIT(p), UNIT_AFTER,
UNIT_REQUIRES,
SPECIAL_SYSINIT_TARGET,
NULL, true);
diff --git a/src/core/socket.c b/src/core/socket.c
index 7eac0eb..4917185 100644
--- a/src/core/socket.c
+++ b/src/core/socket.c
@@ -283,10 +283,6 @@ static int socket_add_default_dependencies(Socket *s) {
int r;
assert(s);
-r = unit_add_dependency_by_name(UNIT(s), UNIT_BEFORE,
SPECIAL_SOCKETS_TARGET, NULL, true);
-if (r 0)
-return r;
-
if (UNIT(s)-manager-running_as == SYSTEMD_SYSTEM) {
r = unit_add_two_dependencies_by_name(UNIT(s), UNIT_AFTER,
UNIT_REQUIRES, SPECIAL_SYSINIT_TARGET, NULL, true);
if (r 0)
diff --git a/src/core/timer.c b/src/core/timer.c
index a4ff662..ae7a07f 100644
--- a/src/core/timer.c
+++ b/src/core/timer.c
@@ -96,10 +96,6 @@ static int timer_add_default_dependencies(Timer *t) {
assert(t);
-r = unit_add_dependency_by_name(UNIT(t), UNIT_BEFORE,
SPECIAL_TIMERS_TARGET, NULL, true);
-if (r 0)
-return r;
-
if (UNIT(t)-manager-running_as == SYSTEMD_SYSTEM) {
r = unit_add_two_dependencies_by_name(UNIT(t), UNIT_AFTER,
UNIT_REQUIRES, SPECIAL_SYSINIT_TARGET, NULL, true);
if (r 0)
--
1.8.5.3
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Re: [systemd-devel] [PATCH] Drop Before=paths/sockets/timers.target from DefaultDependencies.
Alternatively, we should update the man pages to reflect what the DefaultDependencies= option affects. Zbyszek's argument for the patch, however, is that following the recommended WantedBy= behavior already applies the same Before= dependency, and anyone doing otherwise ought not to be subjected to a possibly circular Before= dependency. ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] [PATCH] Drop Before=paths/sockets/timers.target from DefaultDependencies.
В Tue, 28 Jan 2014 13:15:38 -0800 David Timothy Strauss da...@davidstrauss.net пишет: Alternatively, we should update the man pages to reflect what the DefaultDependencies= option affects. Zbyszek's argument for the patch, however, is that following the recommended WantedBy= behavior already applies the same Before= dependency, Where is *this* documented? Unless I misunderstand what you say. and anyone doing otherwise ought not to be subjected to a possibly circular Before= dependency. ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
