The latest webrev looks good to me also.
Thanks,
Paul
From: "linzang(臧琳)" <linz...@tencent.com>
Date: Tuesday, August 11, 2020 at 5:24 PM
To: "serguei.spit...@oracle.com" <serguei.spit...@oracle.com>
Cc: "Hohensee, Paul" <hohen...@amazon.com>, Stefan Karlsson
<stefan.karls...@oracle.com>, David Holmes <david.hol...@oracle.com>,
serviceability-dev <serviceability-dev@openjdk.java.net>,
"hotspot-gc-...@openjdk.java.net" <hotspot-gc-...@openjdk.java.net>
Subject: RE: RFR(L): 8215624: add parallel heap inspection support for jmap
histo(G1)(Internet mail)
Dear Serguei,
Here are the tests I have done:
Generally, the new version of jmap could work with the old
version of hotspot, the “parallel” option tooks no effect.
And the old verdion of jmap could work with the new version of hotspot without
parallel option, and the jvm side works in parallel heap inspection mode by
default. The old jmap could not accept the “parallel” option, so usage
printed.
| histo options | Jmap version | hotspot version
| result |
| no option | latest |
1.8.0.232 | work normally (parallel take no effect) |
| live | latest |
1.8.0_232 | work normally (parallel take no effect) |
| live, parallel=0 | latest | 1.8.0_232
| work normally (parallel take no effect) |
| live, parallel=1 | latest | 1.8.0_232
| work normally (parallel take no effect) |
| live, parallel=2 | latest | 1.8.0_232
| work normally (parallel take no effect) |
| parallel=3 | latest |
1.8.0.232 | work normally (parallel take no effect) |
| no option | latest |
11.0.2 | work normally (parallel take no effect) |
| live | latest |
11.0.2 | work normally (parallel take no effect) |
| live, parallel=0 | latest | 11.0.2
| work normally (parallel take no effect) |
| live, parallel=1 | latest | 11.0.2
| work normally (parallel take no effect) |
| live, parallel=2 | latest | 11.0.2
| work normally (parallel take no effect) |
| parallel=3 | latest |
11.0.2 | work normally (parallel take no effect) |
| no option | latest |
14.0.2 | work normally (parallel take no effect) |
| live | latest |
14.0.2 | work normally (parallel take no effect) |
| live, parallel=0 | latest | 14.0.2
| work normally (parallel take no effect) |
| live, parallel=1 | latest | 14.0.2
| work normally (parallel take no effect) |
| live, parallel=2 | latest | 14.0.2
| work normally (parallel take no effect) |
| parallel=3 | latest |
14.0.2 | work normally (parallel take no effect) |
| no option | 1.8.0.232 | latest
| work normally (parallel by default) |
| live | 1.8.0.232 |
latest | work normally (parallel by default) |
| live, parallel=0 | 1.8.0.232 | latest
| usage printed |
| live, parallel=1 | 1.8.0.232 | latest
| usage printed |
| live, parallel=2 | 1.8.0.232 | latest
| usage printed |
| parallel=3 | 1.8.0.232 | latest
| usage printed |
| no option | 11.0.2 | latest
| work normally (parallel by default) |
| live | 11.0.2 |
latest | work normally (parallel by default) |
| live, parallel=0 | 11.0.2 | latest
| usage printed |
| live, parallel=1 | 11.0.2 | latest
| usage printed |
| live, parallel=2 | 11.0.2 | latest
| usage printed |
| parallel=3 | 11.0.2 | latest
| usage printed |
| no option | 14.0.2 | latest
| work normally (parallel by default) |
| live | 14.0.2 |
latest | work normally (parallel by default) |
| live, parallel=0 | 14.0.2 | latest
| usage printed |
| live, parallel=1 | 14.0.2 | latest
| usage printed |
| live, parallel=2 | 14.0.2 | latest
| usage printed |
| parallel=3 | 14.0.2 | latest
| usage printed |
BRs,
Lin
From: "serguei.spit...@oracle.com" <serguei.spit...@oracle.com>
Date: Wednesday, August 12, 2020 at 4:23 AM
To: "linzang(臧琳)" <linz...@tencent.com>
Cc: "Hohensee, Paul" <hohen...@amazon.com>, Stefan Karlsson
<stefan.karls...@oracle.com>, David Holmes <david.hol...@oracle.com>,
serviceability-dev <serviceability-dev@openjdk.java.net>,
"hotspot-gc-...@openjdk.java.net" <hotspot-gc-...@openjdk.java.net>
Subject: Re: RFR(L): 8215624: add parallel heap inspection support for jmap
histo(G1)(Internet mail)
Hi Lin,
The latest webrev looks good to me.
Just want to double check, how did you check no regressions are introduced with
your fix?
Thanks,
Serguei
On 8/11/20 08:22, linzang(臧琳) wrote:
Hi Serguei,
Thanks a lot for your advice. I agree your concern and will
take care of it in future.
Here is the latest webrev based on your comments: (delta is
just retrieving the usage(1))
http://cr.openjdk.java.net/~lzang/jmap-8214535/8215624/webrev14/
So may I assume that the patch is OK with you now?
Hi All,
In summary, Here are the status of this change at present:
* Paul and Serguei have helped review the runtime/JMap part and
the changes now is Okay with them.
* Stefan has helped review the GC part and it is Okay with him
now.
So does it need more review and approval for pushing this
change?
BRs,
Lin
On 2020/8/11, 2:40 PM,
"serguei.spit...@oracle.com"<mailto:serguei.spit...@oracle.com>
<serguei.spit...@oracle.com><mailto:serguei.spit...@oracle.com> wrote:
Hi Lin,
I prefer a conservative approach and do not change things without a real
need.
Thanks,
Serguei
On 8/10/20 20:23, linzang(臧琳) wrote:
> Hi Serguei
> I got your point, just thought usage may be a little verbosity, it
prints almost my whole screen which could flush the error message. And I
checked that other jcmd tools usually use System.exit() after print errors. So
I made the change.
>
> Thanks!
> Lin
>
>> On Aug 11, 2020, at 11:05 AM,
"serguei.spit...@oracle.com"<mailto:serguei.spit...@oracle.com>
<serguei.spit...@oracle.com><mailto:serguei.spit...@oracle.com> wrote:
>>
>> Hi Lin,
>>
>> I've re-reviewed the JMap.java only.
>> It looks good except there was no need to replace the usage(1) call with
the System.exit(1).
>> I did not say usage is not needed, just that it is not enough.
>>
>> Thanks,
>> Serguei
>>
>>
>>> On 8/10/20 19:25, linzang(臧琳) wrote:
>>> Hi Serguei,
>>> >> First, the CSR does not include any update for 'live' and
'all' options, does it?
>>> >> If so, then I'm confused why do you need all these changes
related to these two options.
>>> >> Did you intend to really change anything?
>>> Yes, you’re correct, CSR doesn’t mention any thing about “live”
and “all”. so all those changes related become unnecessary.
>>>
>>> Webrev:
http://cr.openjdk.java.net/~lzang/jmap-8214535/8215624/webrev_13
>>> Delta:
http://cr.openjdk.java.net/~lzang/jmap-8214535/8215624/webrev_13_delta
>>>
>>> BTW, during refining this changeset I also found an issue that
jmap -dump could accept undefined options, will setup a new issue in JBS and
fix it separately soon.
>>>
>>>
>>> BRs,
>>> Lin
>>>
>>> From: "serguei.spit...@oracle.com"<mailto:serguei.spit...@oracle.com>
<serguei.spit...@oracle.com><mailto:serguei.spit...@oracle.com>
>>> Date: Tuesday, August 11, 2020 at 8:40 AM
>>> To: "linzang(臧琳)" <linz...@tencent.com><mailto:linz...@tencent.com>,
"Hohensee, Paul" <hohen...@amazon.com><mailto:hohen...@amazon.com>, Stefan
Karlsson <stefan.karls...@oracle.com><mailto:stefan.karls...@oracle.com>, David
Holmes <david.hol...@oracle.com><mailto:david.hol...@oracle.com>,
serviceability-dev
<serviceability-dev@openjdk.java.net><mailto:serviceability-dev@openjdk.java.net>,
"hotspot-gc-...@openjdk.java.net"<mailto:hotspot-gc-...@openjdk.java.net>
<hotspot-gc-...@openjdk.java.net><mailto:hotspot-gc-...@openjdk.java.net>
>>> Subject: Re: RFR(L): 8215624: add parallel heap inspection support for
jmap histo(G1)(Internet mail)
>>>
>>> Hi Lin,
>>>
>>> A couple of things.
>>>
>>> First, the CSR does not include any update for 'live' and 'all'
options, does it?
>>> If so, then I'm confused why do you need all these changes related to
these two options.
>>> Did you intend to really change anything?
>>>
>>> Second, new error messages do not look useful as they say nothing about
what is wrong.
>>> Printing usage does not help either.
>>> Could these messages be more specific?
>>> My suggestions are:
>>> 188 if (filename == null) {
>>> 189 System.err.println("Fail at processing option
'" + subopt +"'");
>>> 190 usage(1); // invalid options or no filename
>>> 191 }
>>> System.err.println("Fail: invalid option or no file name: '" +
subopt +"'");
>>> 194 if (parallel == null) {
>>> 195 System.err.println("Fail at processing option
'" + subopt + "'");
>>> 196 usage(1);
>>> 197 }
>>> System.err.println("Fail: no number provided in option: '" + subopt
+"'");
>>> 198 } else {
>>> 199 System.err.println("Fail at processing option '"
+ subopt + "'");
>>> 200 usage(1);
>>> 201 }
>>> System.err.println("Fail: invalid option: '" + subopt +"'");
>>>
>>>
>>> The default value is listed in the 'parallel' flag description:
>>> parallel=<count> generate histogram using this many parallel
threads, default 0
>>> It means that the flag is optionl.
>>>
>>> I'm okay to file a separate enhancement to add a clarification for
'live' and 'all' flags.
>>>
>>> Thanks,
>>> Serguei
>>>
>>>
>>> On 8/10/20 16:46, linzang(臧琳) wrote:
>>> And Here is the latest refined changeset
>>> Webrev:
http://cr.openjdk.java.net/~lzang/jmap-8214535/8215624/webrev_12/
>>> Delta:
http://cr.openjdk.java.net/~lzang/jmap-8214535/8215624/webrev_12_delta/
>>>
>>> BRs,
>>> Lin
>>>
>>> On 2020/8/11, 7:23 AM, "linzang(臧琳)" mailto:linz...@tencent.com wrote:
>>>
>>> Dear Serguei,
>>> Here is my reply for your question about non-numeric
value for “parallel” (somehow the thread of replay became out of order, not
sure why).
>>>
>>> > >> What is going to happen if the resulting 'parallel'
substring above is not a number?
>>> > The error handling logic locates at
http://cr.openjdk.java.net/~lzang/jmap-8214535/8215624/webrev_11/src/hotspot/share/services/attachListener.cpp.frames.html,
(line 276-284)
>>> > Generally, the result is error message will be print if
“parallel” is illegal. An example output would be:
>>> > ############################
>>> > $ time jmap -histo:parallel=c 26233
>>> > Exception in thread "main"
com.sun.tools.attach.AttachOperationFailedException: Invalid parallel thread
number: [c]
>>> > at
jdk.attach/sun.tools.attach.VirtualMachineImpl.execute(VirtualMachineImpl.java:227)
>>> > at
jdk.attach/sun.tools.attach.HotSpotVirtualMachine.executeCommand(HotSpotVirtualMachine.java:309)
>>> > at
jdk.jcmd/sun.tools.jmap.JMap.executeCommandForPid(JMap.java:133)
>>> > at
jdk.jcmd/sun.tools.jmap.JMap.histo(JMap.java:206)
>>> > at
jdk.jcmd/sun.tools.jmap.JMap.main(JMap.java:112)
>>> >
>>> > ############################
>>> >
>>> > Hi Serguei, Paul and Stefan.
>>> > Moreover, I will made a new changeset with following
changes:
>>> > * Print error message + usage when parameter check fail in
Jmap.java
>>> > *Retrive the histo logic that if “all” and “live” are set at
same time, use “live”, rather than print error message. (not sure which one is
better :P)
>>>
>>> My last point is to retrive the behavior for compatibility. And
do you think make a separate enhancement about spec is reasonable ?
>>>
>>> Thanks!
>>>
>>> BRs,
>>> Lin
>>>
>>> From: mailto:serguei.spit...@oracle.com
mailto:serguei.spit...@oracle.com
>>> Date: Tuesday, August 11, 2020 at 5:11 AM
>>> To: "linzang(臧琳)" mailto:linz...@tencent.com,
"<mailto:linz...@tencent.com,>Hohensee, Paul" mailto:hohen...@amazon.com,
Stefan Karlsson mailto:stefan.karls...@oracle.com, David Holmes
mailto:david.hol...@oracle.com, serviceability-dev
mailto:serviceability-dev@openjdk.java.net,
mailto:hotspot-gc-...@openjdk.java.net mailto:hotspot-gc-...@openjdk.java.net
>>> Subject: Re: RFR(L): 8215624: add parallel heap inspection support
for jmap histo(G1)(Internet mail)
>>>
>>> Hi Lin,
>>>
>>>
>>> On 8/7/20 03:41, linzang(臧琳) wrote:
>>> Dear Serguei,
>>> Thanks a lot for your review!
>>> >> The spec says nothing if the new option 'parallel' is mandatory
or optional.
>>> >> Also, (it was before your fix) the spec does not say if the
options 'live' and 'all' are mutually exclusive.
>>> For “parallel”, the spec adds “parallel=0” is the
default behavior. So my assumption is if parallel is not used, it will be 0.
Do you think it is ok ? is it necessary to obviously add comments like “if no
parallel is set, use the default value 0”?
>>>
>>> It'd be nice to make it clear.
>>> But the CSR will need to be updated.
>>> In fact, I did not want you to go through this cycle again.
>>> But maybe it is worth to improve the specs in this regard.
>>> May be Paul has some alternative suggestions.
>>>
>>>
>>> For “live” and “all”, before the changeset , I see the
logic from the code is that both of them can be set at the same time, and the
“live” will take effect. IMHO this may be a little confused. So I made the
change, not sure whether I should keep the same behavior as before in this
change?
>>>
>>> This is better to clearly specify what is allowed and what is the
behavior.
>>>
>>>
>>> And I like your idea of printing more error msg if
something wrong with the options setting, but I checked that before the change,
if there is not a match option, it only print usage. and not only jmap -histo
but also jmap -dump has this issue, do you agree if I fix both in the changeset?
>>>
>>> Yes, it'd be nice to make it clear in both specs.
>>>
>>> >> What is going to happen if null is passed in
place of parallel here? :
>>> The default value 0 will be used if no “parallel” option
is set.
>>>
>>> Okay, thanks.
>>>
>>>
>>> >> Should the lines 193-195 be
moved after the line 202?
>>> I don’t think so, the logic is a little different. At
line 193, the case is “parallel=<blank>”. If move them to line 203, it mean
“parallel” is not optional.
>>> Okay, I see what you mean.
>>> The problem is that the help/spec says nothing about the flag
'parallel' as being optional.
>>>
>>>
>>> I also asked this question:
>>> Q: What is going to happen if the resulting 'parallel'
sub-string above is not a number?
>>>
>>>
>>> Thanks,
>>> Serguei
>>>
>>>
>>>
>>> Thanks!
>>>
>>>
>>> BRs,
>>> Lin
>>>
>>> From: mailto:serguei.spit...@oracle.com
mailto:serguei.spit...@oracle.com
>>> Date: Friday, August 7, 2020 at 3:28 PM
>>> To: "linzang(臧琳)mailto:linz...@tencent.com,Hohensee,
Paulmailto:hohen...@amazon.com,StefanKarlssonmailto:stefan.karls...@oracle.com,DavidHolmesmailto:david.hol...@oracle.com,serviceability-devmailto:serviceability-dev@openjdk.java.net,mailto:hotspot-gc-...@openjdk.java.netmailto:hotspot-gc-...@openjdk.java.netSubject:Re:RFR<mailto:Paulmailto:hohen...@amazon.com,StefanKarlssonmailto:stefan.karls...@oracle.com,DavidHolmesmailto:david.hol...@oracle.com,serviceability-devmailto:serviceability-dev@openjdk.java.net,mailto:hotspot-gc-...@openjdk.java.netmailto:hotspot-gc-...@openjdk.java.netSubject:Re:RFR>(L):8215624:addparallelheapinspectionsupportforjmaphisto(G1)(Internetmail)HiLin,Notsure,Ifullyunderstandthespecupdateandtheoptionsprocessinginthefile:http://cr.openjdk.java.net/~lzang/jmap-8214535/8215624/webrev_11/src/jdk.jcmd/share/classes/sun/tools/jmap/JMap.java.frames.htmlThespecsaysnothingifthenewoption'parallel'ismandatoryoroptional.Also,(itwasbeforeyourfix)thespecdoesnotsayiftheoptions'live'and'all'aremutuallyexclusive.TheJMap.javaimplementationjustprintusageintwocases:191}elseif(subopt.startsWith(parallel="))
{
>>> 192 parallel =
subopt.substring("parallel=".length());
>>> 193 if (parallel == null) {
>>> 194 usage(1);
>>> 195 }
>>> ...
>>> 200 if (set_live && set_all) {
>>> 201 usage(1);
>>> 202 }
>>> It is not that helpful as the usage does not explain anything
about these corner cases.
>>> Also, it allows to pass no parallel option.
>>> What is going to happen if null is passed in place of parallel
here? :
>>> 206 executeCommandForPid(pid, "inspectheap", liveopt,
filename, parallel);
>>>
>>> Should the lines 193-195 be moved after the line 202?
>>>
>>> Thanks,
>>> Serguei
>>>
>>>
>>> On 8/5/20 18:59, linzang(臧琳) wrote:
>>> Thanks Paul!
>>> And I have verified this change could build success in windows.
>>>
>>> BRs,
>>> Lin
>>>
>>> On 2020/8/6, 4:17 AM, "Hohensee,
Paulmailto:hohensee@amazon.comwrote:Twotinynitsthatdon<mailto:Paulmailto:hohensee@amazon.comwrote:Twotinynitsthatdon>'tneedanewwebrev:InheapInspection.cpp,youdon'tneedtocastmissed_counttouintxinthecalltolog_info().InheapInspection.hpp,youcandeletetwoofthethreeblanklinesbefore#endif//SHARE_MEMORY_HEAPINSPECTION_HPPThanks,PaulOn8/5/20,6:46AM,linzang(臧琳)"
mailto:linz...@tencent.com wrote:
>>>
>>> Hi Paul, Stefan and Serguei,
>>> Here I uploaded a new changeset, would you like to
help review again?
>>> Webrev:
http://cr.openjdk.java.net/~lzang/jmap-8214535/8215624/webrev_11/
>>> Delta (based on webrev10):
http://cr.openjdk.java.net/~lzang/jmap-8214535/8215624/webrev_11_delta/
>>>
>>> P.S. I am in process of building it on windows
environment for a double check. May update result later. Thanks!
>>>
>>>
>>> BRs,
>>> Lin
>>>
>>>
>>>
>>>
>>>
>>
