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

[Vladimir Kozlov]

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
>      >      >
>      >      >
>      >
>      >
>      
>