Critical It seems the p4 plugin is simply hung on this p4 command. This is the second time it has happened, the first time was probably about two months ago (don't have logs from that time). We usually have at least one build occur every day, if not multiple. So it seems very infrequent but when it does happen, hitting the 'x' to cancel the build does not affect it and that Jenkins executor stays hung. So my only course of action that I know of is to kill the Jenkins service and restart it.
Here is the last output on the Jenkins console:
P4 Task: reverting all pending and shelved revisions. ... p4 revert C:\Jenkins\jobs\Sepac_x.58\workspace\buildType\standard\osType\linux\spec___ - p4 revert C:\Jenkins\jobs\Sepac_x.58\workspace\buildType\standard\osType\linux\specialBuild\none/... C:\Jenkins\jobs\Sepac_x.58\workspace\buildType\standard\osType\linux\specialBuild\none/... - file(s) not opened on this client. ... rm [abandoned files] duration: (78ms) P4 Task: cleaning workspace to match have list. ... p4 reconcile -w -f C:\Jenkins\jobs\Sepac_x.58\workspace\buildType\standard\osType\l___ - p4 reconcile -w -f C:\Jenkins\jobs\Sepac_x.58\workspace\buildType\standard\osType\linux\specialBuild\none/...
Attached is a thread dump of my Jenkins.
[JENKINS-40355] P4 hangs on reconcile call
Brian Collum
added a comment - Hey mksmith, no we never resolved it per se. But we have not actually run into this since I entered this ticket.
Brian Collum
added a comment - Hey mksmith , no we never resolved it per se. But we have not actually run into this since I entered this ticket. 
Paul Allen
added a comment - Closing issue as 'cannot reproduce'.
Reconcile can be quite memory intensive for the client, although back in 1.4.4 I introduced a streaming callback to reduce memory. The streaming callback could be sensitive to packet loss/missing ACKs, which could have caused the issue.
Please reopen if you are experiencing more hang-ups on reconcile.
Paul Allen
added a comment - Closing issue as 'cannot reproduce'.
Reconcile can be quite memory intensive for the client, although back in 1.4.4 I introduced a streaming callback to reduce memory. The streaming callback could be sensitive to packet loss/missing ACKs, which could have caused the issue.
Please reopen if you are experiencing more hang-ups on reconcile. 
Sonam Chakravarti
added a comment - This issue happens on my CI/CD set up quite often and the only way I get rid of the stuck job is by restarting Jenkins Service. Am I missing something as this happens only on particular perforce depot. No other project has its job behaving this way.
Sonam Chakravarti
added a comment - This issue happens on my CI/CD set up quite often and the only way I get rid of the stuck job is by restarting Jenkins Service. Am I missing something as this happens only on particular perforce depot. No other project has its job behaving this way. Hi sonamchakravarti, please can you confirm the p4-plugin version, p4d version and your server configurables 'p4 configure show'. If you have support with Perforce, please raise a ticket with the version information and reference the JIRA issue.
In addition, please find out when your Perforce server performs a checkpoint or other administration tasks that would lock the database.
Paul Allen
added a comment - - edited Hi sonamchakravarti , please can you confirm the p4-plugin version, p4d version and your server configurables 'p4 configure show'. If you have support with Perforce, please raise a ticket with the version information and reference the JIRA issue.
In addition, please find out when your Perforce server performs a checkpoint or other administration tasks that would lock the database. Paul Allen
added a comment - Closing old issue - newer versions of the p4-plugin use streaming callback support for sync and reconcile commands reducing load on memory.
Paul Allen
added a comment - Closing old issue - newer versions of the p4-plugin use streaming callback support for sync and reconcile commands reducing load on memory. 
Hi Brian, did you ever resolve this issue? We are seeing the same thing