P3
In the -Xlog:help, at the bottom it shows using "rt" in the disable example but "rt" is not shown in the "Available log tags" above that. See below.
This is with 9b113.
$ ./build/linux-x64/images/jdk/bin/java -Xlog:help
-Xlog Usage: -Xlog[:[what][:[output][:[decorators][:output-options]]]]
where 'what' is a combination of tags and levels on the form tag1[+tag2...][*][=level][,...]
Unless wildcard (*) is specified, only log messages tagged with exactly the tags specified will be matched.
Available log levels:
off, trace, debug, info, warning, error
Available log decorators:
time (t), uptime (u), timemillis (tm), uptimemillis (um), timenanos (tn), uptimenanos (un), hostname (hn), pid (p), tid (ti), level (l), tags (tg)
Decorators can also be specified as 'none' for no decoration.
Available log tags:
alloc, age, barrier, biasedlocking, bot, census, classhisto, classresolve, classinit, classload, classloaderdata, classunload, classpath, compaction, cpu, cset, defaultmethods, ergo, exceptions, exit, freelist, gc, heap, humongous, ihop, itables, jni, liveness, logging, marking, metaspace, modules, monitorinflation, os, phases, plab, promotion, protectiondomain, ref, refine, region, remset, safepoint, scavenge, scrub, start, startuptime, state, stats, stringdedup, survivor, sweep, task, thread, tlab, time, verify, vmoperation, vtables
Specifying 'all' instead of a tag combination matches all tag combinations.
Available log outputs:
stdout, stderr, file=<filename>
Specifying %p and/or %t in the filename will expand to the JVM's PID and startup timestamp, respectively.
Some examples:
-Xlog
Log all messages using 'info' level to stdout with 'uptime', 'levels' and 'tags' decorations.
(Equivalent to -Xlog:all=info:stdout:uptime,levels,tags).
-Xlog:gc
Log messages tagged with 'gc' tag using 'info' level to stdout, with default decorations.
-Xlog:gc=debug:file=gc.txt:none
Log messages tagged with 'gc' tag using 'debug' level to file 'gc.txt' with no decorations.
-Xlog:gc=trace:file=gctrace.txt:uptimemillis,pids:filecount=5,filesize=1024
Log messages tagged with 'gc' tag using 'trace' level to a rotating fileset of 5 files of size 1MB,
using the base name 'gctrace.txt', with 'uptimemillis' and 'pid' decorations.
-Xlog:gc::uptime,tid
Log messages tagged with 'gc' tag using 'info' level to output 'stdout', using 'uptime' and 'tid' decorations.
-Xlog:gc*=info,rt*=off
Log messages tagged with at least 'gc' using 'info' level, but turn off logging of messages tagged with 'rt'.
(Messages tagged with both 'gc' and 'rt' will not be logged.)
-Xlog:disable -Xlog:rt=trace:rttrace.txt
Turn off all logging, including warnings and errors,
and then enable messages tagged with 'rt' using 'trace' level to file 'rttrace.txt'.
This is with 9b113.
$ ./build/linux-x64/images/jdk/bin/java -Xlog:help
-Xlog Usage: -Xlog[:[what][:[output][:[decorators][:output-options]]]]
where 'what' is a combination of tags and levels on the form tag1[+tag2...][*][=level][,...]
Unless wildcard (*) is specified, only log messages tagged with exactly the tags specified will be matched.
Available log levels:
off, trace, debug, info, warning, error
Available log decorators:
time (t), uptime (u), timemillis (tm), uptimemillis (um), timenanos (tn), uptimenanos (un), hostname (hn), pid (p), tid (ti), level (l), tags (tg)
Decorators can also be specified as 'none' for no decoration.
Available log tags:
alloc, age, barrier, biasedlocking, bot, census, classhisto, classresolve, classinit, classload, classloaderdata, classunload, classpath, compaction, cpu, cset, defaultmethods, ergo, exceptions, exit, freelist, gc, heap, humongous, ihop, itables, jni, liveness, logging, marking, metaspace, modules, monitorinflation, os, phases, plab, promotion, protectiondomain, ref, refine, region, remset, safepoint, scavenge, scrub, start, startuptime, state, stats, stringdedup, survivor, sweep, task, thread, tlab, time, verify, vmoperation, vtables
Specifying 'all' instead of a tag combination matches all tag combinations.
Available log outputs:
stdout, stderr, file=<filename>
Specifying %p and/or %t in the filename will expand to the JVM's PID and startup timestamp, respectively.
Some examples:
-Xlog
Log all messages using 'info' level to stdout with 'uptime', 'levels' and 'tags' decorations.
(Equivalent to -Xlog:all=info:stdout:uptime,levels,tags).
-Xlog:gc
Log messages tagged with 'gc' tag using 'info' level to stdout, with default decorations.
-Xlog:gc=debug:file=gc.txt:none
Log messages tagged with 'gc' tag using 'debug' level to file 'gc.txt' with no decorations.
-Xlog:gc=trace:file=gctrace.txt:uptimemillis,pids:filecount=5,filesize=1024
Log messages tagged with 'gc' tag using 'trace' level to a rotating fileset of 5 files of size 1MB,
using the base name 'gctrace.txt', with 'uptimemillis' and 'pid' decorations.
-Xlog:gc::uptime,tid
Log messages tagged with 'gc' tag using 'info' level to output 'stdout', using 'uptime' and 'tid' decorations.
-Xlog:gc*=info,rt*=off
Log messages tagged with at least 'gc' using 'info' level, but turn off logging of messages tagged with 'rt'.
(Messages tagged with both 'gc' and 'rt' will not be logged.)
-Xlog:disable -Xlog:rt=trace:rttrace.txt
Turn off all logging, including warnings and errors,
and then enable messages tagged with 'rt' using 'trace' level to file 'rttrace.txt'.