When traversing entry array chains for a bisection or for retrieving an
item by index we previously always started at the beginning of the
chain. Since we tend to look at the same chains repeatedly, let's cache
where we have been the last time, and maybe we can skip ahead with this
the next time.
This turns most bisections and index lookups from O(log(n)*log(n)) into
O(log(n)). More importantly however, we seek around on disk much less,
which is good to reduce buffer cache and seek times on rotational disks.
https://bugs.freedesktop.org/show_bug.cgi?id=55890
Fixed typos, serial comma, and removed "either" as there were more
than two options. Also did an extra rename of "system-shutdown"
to "systemd-shutdown" that was forgotten in commit
8bd3b8620c
I hit an "assert(j->installed)" failure in transaction_apply(). Looking
into the backtrace I saw what happened:
1. The system was booting. var.mount/start was an installed job.
2. I pressed Ctrl+Alt+Del.
3. reboot.target was going to be isolated.
4. transaction_apply() proceeded to install a var.mount/stop job.
5. job_install() canceled the conflicting start job.
6. Depending jobs ended recursively with JOB_DEPENDENCY, among them was
local-fs.target/start.
7. Its OnFailure action triggered - emergency.target was now going to be
isolated.
8. We recursed back into transaction_apply() where the half-installed
var.mount/stop job confused us.
Recursing from job installation back into the transaction code cannot be
a good idea. Avoid the problem by canceling the conflicting job
non-recursively in job_install(). I don't think we'll miss anything by
not recursing here. After all, we are called from transaction_apply().
We will not be installing just this one job, but all jobs from a
transaction. All requirement dependencies will be included in it and
will be installed separately. Every transaction job will get a chance
to cancel its own conflicting installed job.
Mostly useful for testing purposes. Setting Age to 1s works just as
well, but it is surprising that using 0s (or just 0) does not work.
Also clarify this in the documentation.
HP iLO fw versions below 1.50 incorrectly report that HP iLO virtual
Kbd/Mouse supports remote wakeup. With the rules change in commit
3bfc7a97b1, the HP iLO was listed for
power control.
In iLO fw versions less than 1.50, the iLO Kbd/Mouse become unresponsive
once they are suspended. HP iLO fw versions 1.50+ correctly report that
they don't support remote wakeup, which makes the rules moot in any case.
If you enter unit_add_exec_dependencies with m->where = NULL, you'll
very likely end up aborting somewhere under socket_needs_mount.
(When systemd goes to check to see if the journald socket requires your
mount, it'll do path_startswith(path, m->where)... *kaboom*)
This patch should ensure that:
a) both branches in mount_add_one() set m->where, and
b) mount_add_extras() calls unit_add_exec_dependencies() *after*
setting m->where.
