On the unified hierarchy, blkio controller is renamed to io and the interface
is changed significantly.
* blkio.weight and blkio.weight_device are consolidated into io.weight which
uses the standardized weight range [1, 10000] with 100 as the default value.
* blkio.throttle.{read|write}_{bps|iops}_device are consolidated into io.max.
Expansion of throttling features is being worked on to support
work-conserving absolute limits (io.low and io.high).
* All stats are consolidated into io.stats.
This patchset adds support for the new interface. As the interface has been
revamped and new features are expected to be added, it seems best to treat it
as a separate controller rather than trying to expand the blkio settings
although we might add automatic translation if only blkio settings are
specified.
* io.weight handling is mostly identical to blkio.weight[_device] handling
except that the weight range is different.
* Both read and write bandwidth settings are consolidated into
CGroupIODeviceLimit which describes all limits applicable to the device.
This makes it less painful to add new limits.
* "max" can be used to specify the maximum limit which is equivalent to no
config for max limits and treated as such. If a given CGroupIODeviceLimit
doesn't contain any non-default configs, the config struct is discarded once
the no limit config is applied to cgroup.
* lookup_blkio_device() is renamed to lookup_block_device().
Signed-off-by: Tejun Heo <htejun@fb.com>
The "resources" error is really just the generic error we return when
we hit some kind of error and we have no more appropriate error for the case to
return, for example because of some OS error.
Hence, reword the explanation and don't claim any relation to resource limits.
Admittedly, the "resources" service error is a bit of a misnomer, but I figure
it's kind of API now.
Fixes: #2716
Previously we'd have generally useful sd-bus utilities in bust-util.h,
intermixed with code that is specifically for writing clients for PID 1,
wrapping job and unit handling. Let's split the latter out and move it into
bus-unit-util.c, to make the sources a bit short and easier to grok.
This adds a new GetProcesses() bus call to the Unit object which returns an
array consisting of all PIDs, their process names, as well as their full cgroup
paths. This is then used by "systemctl status" to show the per-unit process
tree.
This has the benefit that the client-side no longer needs to access the
cgroupfs directly to show the process tree of a unit. Instead, it now uses this
new API, which means it also works if -H or -M are used correctly, as the
information from the specific host is used, and not the one from the local
system.
Fixes: #2945
