Some functionality in Linux Job may go away in order to make use of a
possible replacement for PAGG/pnotify in the kernel (task notifiers from Jack
Steiner if you follow lse-tech).
There is opposition (not from me) to having locks in similar places that
PAGG/pnotify had, so operations that allow a random process to operate on the
Job data of another random process will no longer be available.
This means these library calls may go away:
job_detachjid
job_detachpid
job_attachpid
These two job commands make use of the above functions and would also be
purged:
jattach
jdetach
Further, due to the same locking issues, looking up a JID given a PID will
not be as efficient. If these operations are in any 'hot paths', performance
will be reduced. I believe job_getjid calls will be the main issue here.
It appears I may need to add two new library calls - a job_detach call
that detaches the current process from a job, and a job_attach function
that attaches the 'current' process to a supplied job. But these
functions would only operateon the current running process, not
other processes on the system.
I need to be aware, ASAP, if we know of any customers, companies, or
community people making use of functionality that may be purged or less
efficient. If the functionality proposed for removal is known to be used by
customers or the community, it would be justification for us to push for
locking similar to PAGG/pnotify. Please let me know.
--
Erik Jacobson - Linux System Software - Silicon Graphics - Eagan, Minnesota
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