[RFR]8215623: Add incremental dump for jmap histo
Jean Christophe Beyler
jcbeyler at google.com
Fri Apr 12 18:15:24 UTC 2019
Hi Lin,
You could state in the CSR:
- That not using the new flags makes the system behave as before; so it
is a nop if you don't use the new flags
- What happens if the flags are passed negative values?
- What happens if the flags are passed crazy big numbers?
Finally, I'd put a link to the current webrev if someone wanted more
information.
Apart from that, it looks good to me (I might skip the diff as you put the
output below) the text could just say: here is the new usage text
(maxchunk and maxfilesize are new)
Thanks,
Jc
On Wed, Apr 10, 2019 at 11:56 PM 臧琳 <zanglin5 at jd.com> wrote:
> Dear All,
> I have created a CSR at
> https://bugs.openjdk.java.net/browse/JDK-8222319.
> May I ask your help to review it? Thanks!
>
>
> BRs,
> Lin
>
> 在 2019年4月11日，上午11:22，臧琳 <zanglin5 at jd.com> 写道：
>
> Sorry, it should be CSR ticket
>
> Thanks，
> Lin
>
> 在 2019年4月11日，上午11:16，臧琳 <zanglin5 at jd.com> 写道：
>
> Also realized it requires a JCP ticket, I will create it.
>
>
> Cheers,
> Lin
>
> 在 2019年4月11日，上午10:26，臧琳 <zanglin5 at jd.com> 写道：
>
>
> Dear JC,
> Thanks so much, I suddenly realized your way is exactly what I want.
> And here is new wehbrev.
> http://cr.openjdk.java.net/~lzang/jmap-8214535/8215623/webrev.06/
>
>
> BRs,
> Lin
>
> 在 2019年4月11日，上午4:40，Jean Christophe Beyler <jcbeyler at google.com> 写道：
>
> Hi Lin,
>
> What I meant about the helper method was to not do this:
>
>
> + private static String add_option(String cmd, String opt) {
> + if (opt.equals("")) {
> + return cmd;
> + }
> + return cmd + opt + ",";
> + }
> +
>
> but to do this:
>
> + private static String add_option(String cmd, String opt) {
> + if (cmd.isEmpty()) {
> + return opt;
> + }
> + return cmd + "," + opt;
> + }
> +
>
> That way you only put the ',' when needed,
> Jc
>
>
>
> On Wed, Apr 10, 2019 at 5:33 AM 臧琳 <zanglin5 at jd.com> wrote:
>
>> Dear Jc,
>> Thanks a lot for your comments, here is the refined webrev. May I
>> ask your help to review again?
>> http://cr.openjdk.java.net/~lzang/jmap-8214535/8215623/webrev.05/
>>
>> BRs,
>> Lin
>>
>> 在 2019年4月4日，上午4:57，Jean Christophe Beyler <jcbeyler at google.com> 写道：
>>
>> Hi Lin,
>>
>> Just a few nits to be honest:
>>
>> -
>> http://cr.openjdk.java.net/~lzang/jmap-8214535/8215623/webrev.04/src/hotspot/share/utilities/ostream.cpp.udiff.html
>>
>> -> I don't think it's a good idea to just pass a char* and implicitly
>> imagine it is 256 in length
>> -> Should we not add that length as a parameter? btw, the test you have
>> len > 255 is a bit too restrictive no? Technically you should wait until
>> you find the last '/' and then test there no?
>> (technically we could use strrchr, no?)
>>
>>
>> http://cr.openjdk.java.net/~lzang/jmap-8214535/8215623/webrev.04/src/jdk.jcmd/share/classes/sun/tools/jmap/JMap.java.udiff.html
>> -> the adding of the "," seems a bit off; I think it would be smarter
>> to just have a helper add_option to cmdline that checks if it is not empty,
>> then add "," and the new option
>> -> otherwise you always end the "," if there are more options even
>> if you are ignoring them, no?
>>
>> Finally:
>> } else if (subopt.equals("live")) {
>> - liveopt = "-live";
>> + // Add '-' for compatibility.
>> + cmdline += "-" + subopt;
>>
>> for consistency with how you do it for "all", should this not be:
>> } else if (subopt.equals("live")) {
>> - liveopt = "-live";
>> + // Add '-' for compatibility.
>> + cmdline += "-live";
>>
>> Thanks,
>> Jc
>>
>> On Mon, Apr 1, 2019 at 5:18 AM 臧琳 <zanglin5 at jd.com> wrote:
>>
>>> Dear All，
>>> Here I updated the latest changeset which did the following refine:
>>> * fixed the compatibility issues so that old version of jmap can
>>> work normally with latest changeset.
>>> * revised the code for parsing the jmap histo arguments.
>>> * revised the logic for incremental dumping of jmap histo.
>>> The main change of this webrev is making all arguments passed to
>>> virtual machine as one line. So there is no need to care about the max
>>> argument count limitation. And hence resolved the compatibility issues as
>>> discussed in
>>> http://mail.openjdk.java.net/pipermail/serviceability-dev/2019-March/027338.html
>>>
>>> May I ask your help to review?
>>> http://cr.openjdk.java.net/~lzang/jmap-8214535/8215623/webrev.04/
>>>
>>>
>>> BRs,
>>> Lin
>>>
>>> 在 2019年2月26日，上午10:50，臧琳 <zanglin5 at jd.com> 写道：
>>>
>>> Dear All,
>>> I have revised the webrev at
>>> http://cr.openjdk.java.net/~xiaofeya/8215623/webrev.02/.
>>> May I ask your help for reviewing? Thanks
>>>
>>>
>>> BRs,
>>> Lin
>>>
>>> -----Original Message-----
>>> From: 臧琳
>>> Sent: Friday, January 25, 2019 9:01 AM
>>> To: Hohensee, Paul <hohensee at amazon.com>; serviceability-
>>> dev at openjdk.java.net
>>> Subject: Re: [RFR]8215623: Add incremental dump for jmap histo
>>>
>>> Dear All,
>>> May I get more review about this webrev?
>>> Webrev: http://cr.openjdk.java.net/~xiaofeya/8215623/webrev.01/
>>> Bug: https://bugs.openjdk.java.net/browse/JDK-8215623
>>>
>>>
>>> Thanks!
>>> Lin
>>> ________________________________________
>>> From: 臧琳
>>> Sent: Wednesday, January 9, 2019 9:46:55 AM
>>> To: Hohensee, Paul; serviceability-dev at openjdk.java.net
>>> Subject: RE: [RFR]8215623: Add incremental dump for jmap histo
>>>
>>> Hi Paul and All,
>>> Thanks a lot for your review and comments, I have updated the webrev
>>> to
>>>
>>> Webrev: http://cr.openjdk.java.net/~xiaofeya/8215623/webrev.01/
>>>
>>> Bug: https://bugs.openjdk.java.net/browse/JDK-8215623
>>> Would you like to help review it. Thanks.
>>>
>>> BRs
>>> Lin
>>>
>>> From: 臧琳
>>> Sent: Monday, January 7, 2019 7:14 PM
>>> To: Hohensee, Paul <hohensee at amazon.com>; serviceability-
>>> dev at openjdk.java.net; 臧琳 <zanglin5 at jd.com>
>>> Subject: RE: [RFR]8215623: Add incremental dump for jmap histo
>>>
>>> And another way is to add a argument “IncrementalFile=<path>”,which
>>> specifies the location for saving the intermediate data file. And if it
>>> is not
>>> specified, incremental data will dump to “out”.
>>>
>>> What do you think?
>>>
>>> Thanks,
>>> Lin
>>> From: 臧琳
>>> Sent: Monday, January 7, 2019 7:02 PM
>>> To: Hohensee, Paul
>>> <hohensee at amazon.com<mailto:hohensee at amazon.com>>; serviceability-
>>> dev at openjdk.java.net<mailto:serviceability-dev at openjdk.java.net>
>>> Subject: 答复: [RFR]8215623: Add incremental dump for jmap histo
>>>
>>>
>>> Dear Paul,
>>>
>>> Thanks for your review, I agree your suggestion to make
>>> incremental
>>> general. and
>>>
>>> I think the incremental file is better to be different with the
>>> file or the
>>> "out", because
>>>
>>> in future the parallel histo will have each thread individually dump
>>> their data,
>>> and I want
>>>
>>> it to be lock-free, so each thread need to dump to their own file. The
>>> final
>>> data
>>>
>>> will be sum up and dump to the file that "filename=<file>" specified.
>>> Moreover, the incremental
>>>
>>> file contains intermediate data, if it is dumped to "<file>", it more or
>>> less
>>> "pollute" the final file (final file that contains lots intermediate
>>> data).
>>>
>>> so the logic is that incremental data will be dumped to a file
>>> named
>>> "Histo_Dump_Temp.dump",
>>>
>>> if the "filename" is assigned, the "Histo_Dump_Temp.dump" will be
>>> generated under the same folder,
>>>
>>> if "filename" not specified, it will dump to current dir. And if
>>> "chunkcount" is 0
>>> or max_int, or "maxfilesize" is 0, the incremental dump will be disabled.
>>>
>>> ________________________________
>>> 发件人: Hohensee, Paul
>>> <hohensee at amazon.com<mailto:hohensee at amazon.com>>
>>> 发送时间: 2019年1月1日 4:56
>>> 收件人: 臧琳; serviceability-dev at openjdk.java.net<mailto:serviceability-
>>> dev at openjdk.java.net>
>>> 主题: Re: [RFR]8215623: Add incremental dump for jmap histo
>>>
>>>
>>> As for 8215622, update the copyright dates to 2019 please, since this
>>> won’t
>>> get pushed until then.
>>>
>>>
>>>
>>> You might generalize the implementation so that all inspections are done
>>> incrementally, and parameterize RecordInstanceClosure with the
>>> incremental
>>> threshold. “incremental” could become “chunkcount=<n>”, where <n>
>>> defaults to infinity (max value of size_t).
>>>
>>>
>>>
>>> I’d not use a default file name when “chunkcount” is specified, I’d just
>>> write to
>>> whatever the output stream is. “chunkcount” is then independent of
>>> “file”.
>>>
>>>
>>>
>>> I’d add another histo argument for the maximum file size, call it
>>> “maxfilesize”,
>>> and parameterize RecordInstanceClosure with it. Default would be infinity
>>> (max value of size_t).
>>>
>>>
>>>
>>> If you want to make it easy to use your 8k and 5mb chunkcount and
>>> maxfilesize combination, you could redefine your original “incremental”
>>> argument as syntactic sugar for “chunkcount=8k,maxfilesize=5m”.
>>>
>>>
>>>
>>> INCREMENTAL_THRESHOLD and MAX_INCREMENTAL_FILESIZE become
>>> DEFAULT_CHUNKSIZE and MAX_FILE_SIZE, are both set to max size_t, and
>>> should be defined as “const int” within RecordInstanceClosure.
>>>
>>>
>>>
>>> Thanks,
>>>
>>>
>>>
>>> Paul
>>>
>>>
>>>
>>> From: serviceability-dev <serviceability-dev-
>>> bounces at openjdk.java.net<mailto:serviceability-dev-
>>> bounces at openjdk.java.net>> on behalf of 臧琳
>>> <zanglin5 at jd.com<mailto:zanglin5 at jd.com>>
>>> Date: Thursday, December 20, 2018 at 11:13 PM
>>> To: "serviceability-dev at openjdk.java.net<mailto:serviceability-
>>> dev at openjdk.java.net>" <serviceability-
>>> dev at openjdk.java.net<mailto:serviceability-dev at openjdk.java.net>>
>>> Subject: [RFR]8215623: Add incremental dump for jmap histo
>>>
>>>
>>>
>>> Hi All,
>>>
>>> May I ask your help to review this patch for enhance jmap –histo.
>>>
>>> It adds the “incremental” arguments that allow jmap –histo to
>>> incrementally
>>> save the intermediate data into a temp file.
>>>
>>> The intermediate data is dumped incrementally and write to a rolling
>>> file,
>>> which limit the size of the temp file to be small.
>>>
>>> This is useful for user to get intermediate results when jmap/jvm
>>> process is
>>> killed accidentally. Especially when the heap is large.
>>>
>>>
>>>
>>> This patch is also part of the enhancement described in
>>> https://bugs.openjdk.java.net/browse/JDK-8214535.
>>>
>>>
>>>
>>> Webrev: http://cr.openjdk.java.net/~xiaofeya/8215623/webrev.00/
>>>
>>> Bug: https://bugs.openjdk.java.net/browse/JDK-8215623
>>>
>>>
>>>
>>> Thanks.
>>>
>>>
>>>
>>> BRs,
>>>
>>> Lin
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>
>> --
>>
>> Thanks,
>> Jc
>>
>>
>>
>
> --
>
> Thanks,
> Jc
>
>
>
>
>
>
--
Thanks,
Jc
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