RFR(S, tedious): 8217250: Optimize CodeHeap Analytics

Tobias Hartmann tobias.hartmann at oracle.com
Fri Jan 18 09:49:14 UTC 2019


Hi Lutz,

looks good to me too.

Best regards,
Tobias

On 17.01.19 19:39, Vladimir Kozlov wrote:
> Looks good
> 
> Thanks,
> Vladimir
> 
> On 1/17/19 7:47 AM, Schmidt, Lutz wrote:
>> Hi Vladimir & all,
>> there is a new webrev available: http://cr.openjdk.java.net/~lucy/webrevs/8217250.01/
>> What's new (in addition to some comments) is the macro
>>
>>    // Flush the buffer contents if the remaining capacity is less
>>    // than the calculated threshold (256 bytes + capacity/16)
>>    // That should suffice for all reasonably sized output lines.
>>    #define BUFFEREDSTREAM_FLUSH_AUTO(_termString)                \
>>        BUFFEREDSTREAM_FLUSH_IF(_termString, 256+(_capacity>>4))
>>
>> It replaced the previous BUFFEREDSTREAM_FLUSH_IF("string", 512) occurrences.
>> Regards,
>> Lutz
>>
>> On 16.01.19, 22:53, "Vladimir Kozlov" <vladimir.kozlov at oracle.com> wrote:
>>
>>      On 1/16/19 12:37 PM, Schmidt, Lutz wrote:
>>      > Hi Vladimir,
>>      >
>>      > thanks a lot for looking at this so quickly.
>>      >
>>      > Sure, I could declare a specialized "BUFFEREDSTREAM_FLUSH_512" for this. The "512"
>> originated from the thought "its large enough for a well-behaved line and small enough to save
>> some flushes".
>>      >
>>      > I was also thinking about a "BUFFEREDSTREAM_FLUSH_AUTO", where the spare space is derived
>> from the buffer capacity, maybe something like 10 percent of the capacity, 256 bytes minimum. I
>> wasn't sure if that could be categorized as over-engineered.
>>           Yes, I think BUFFEREDSTREAM_FLUSH_AUTO is better than fixed size.
>>           Vladimir
>>           >
>>      > Your thoughts?
>>      >
>>      > Thanks,
>>      > Lutz
>>      >
>>      > On 16.01.19, 19:10, "hotspot-compiler-dev on behalf of Vladimir Kozlov"
>> <hotspot-compiler-dev-bounces at openjdk.java.net on behalf of vladimir.kozlov at oracle.com> wrote:
>>      >
>>      >      Hi Lutz,
>>      >
>>      >      I see that you have only one usage in all cases for:
>>      >      BUFFEREDSTREAM_FLUSH_IF("", 512)
>>      >
>>      >      Can you simple declare simplified macro for this?
>>      >
>>      >      Otherwise looks good.
>>      >
>>      >      Thanks,
>>      >      Vladimir
>>      >
>>      >      On 1/16/19 6:52 AM, Schmidt, Lutz wrote:
>>      >      > Dear all,
>>      >      >
>>      >      > may I please have reviews for this (semantically) small change. Its purpose is to
>> reduce the bufferedStream buffer flushes while printing CodeHeap Analytics.
>>      >      >
>>      >      > Bug:    https://bugs.openjdk.java.net/browse/JDK-8217250
>>      >      > Webrev: http://cr.openjdk.java.net/~lucy/webrevs/8217250.00/
>>      >      >
>>      >      > Thank you!
>>      >      > Lutz
>>      >      >
>>      >      >
>>      >
>>      >
>>     


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