[8u] RFR: 8217766: Container Support doesn't work for some Join Controllers combinations

[Andrew Hughes]

On 15:32 Tue 27 Oct     , Severin Gehwolf wrote:
> Hi!
> 
> Could I please get a review for this 8u backport of 8217766. I see
> Oracle backported it too to 8u281. The JDK 11 patch does not apply
> cleanly, because a) no unified logging in hotspot in 8u b) split of jdk
> and hotspot repositories in 8u.
> 
> I've manually backported hotspot changes. The JDK changes actually
> applied cleanly. While this fixes part of the problem. JDK-8254854 will
> be fixed separately and as a follow-up.
> 
> Bug: https://bugs.openjdk.java.net/browse/JDK-8217766
> webrev: http://cr.openjdk.java.net/~sgehwolf/webrevs/JDK-8217766/01/
> 
> Testing: Manually on affected system with join controllers[1].
> Container tests on Linux x86_64: no regressions.
> 
> Thoughts?
> 
> Thanks,
> Severin
> 
> [1] https://bugs.openjdk.java.net/browse/JDK-8217766?focusedCommentId=14373516&page=com.atlassian.jira.plugin.system.issuetabpanels%3Acomment-tabpanel#comment-14373516
> 

A blank line (before the mountinfo comment) gets lost in the backport
from 11u to 8u, causing the diffs of osContainer_linux.cpp to not line
up. You can see this after applying your patch and comparing the two
files:

@@ -262,13 +324,14 @@
     char tmpcgroups[MAXPATHLEN+1];
     char *cptr = tmpcgroups;
     char *token;
+
     // mountinfo format is documented at https://www.kernel.org/doc/Documentation/filesystems/proc.txt
     if (sscanf(p, "%*d %*d %*d:%*d %s %s %*[^-]- cgroup %*s %s", tmproot, tmpmount, tmpcgroups) != 3) {
       continue;
     }
     while ((token = strsep(&cptr, ",")) != NULL) {
       if (strcmp(token, "memory") == 0) {
-        memory = new CgroupSubsystem(tmproot, tmpmount);
+        memory = new CgroupMemorySubsystem(tmproot, tmpmount);
       } else if (strcmp(token, "cpuset") == 0) {
         cpuset = new CgroupSubsystem(tmproot, tmpmount);
       } else if (strcmp(token, "cpu") == 0) {

Not only does this make it hard to compare your backport with the
original to see what changed, it will cause unnecessary context
differences for future backports. Please rectify this.

Thanks,
-- 
Andrew :)

Senior Free Java Software Engineer
OpenJDK Package Owner
Red Hat, Inc. (http://www.redhat.com)

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