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From "Mikhail Loenko" <mloe...@gmail.com>
Subject Re: [drlvm] things feel slow...
Date Sat, 23 Dec 2006 17:48:45 GMT
Can you publish most common stacks for the
"157114 Ljava/io/ByteArrayOutputStream;.write(I)V"

Thanks,
Mikhail


2006/12/23, Gregory Shimansky <gshimansky@gmail.com>:
> On Saturday 23 December 2006 04:09 Stefano Mazzocchi wrote:
> > Gregory Shimansky wrote:
> > > I was not aware that drlvm didn't generate MethodEnter/Exit events for
> > > native methods when I wrote this email. Now after applying HARMONY-2828
> > > which fills this gap I've rerun my test agent and the top10 for most
> > > called methods to run hello world application has changed. The new top10
> > > list looks like this:
> > >
> > >  157114 Ljava/io/ByteArrayOutputStream;.write(I)V
> > >   20093 Ljava/lang/Object;.<init>()V
> > >   13975 Ljava/lang/String;.hashCode()I
> > >    9301 Ljava/lang/Character;.toLowerCase(C)C
> > >    7842 Ljava/io/ByteArrayOutputStream;.size()I
> > >    7692 Ljava/lang/String;.<init>(II[C)V
> > >    6300
> > > Ljava/lang/VMMemoryManager;.arrayCopy(Ljava/lang/Object;ILjava/lang/Objec
> > >t;II)V 6300
> > > Ljava/lang/System;.arraycopy(Ljava/lang/Object;ILjava/lang/Object;II)V
> > > 6248 Ljava/lang/String;.length()I
> > >    6130 Ljava/lang/String;.substring(II)Ljava/lang/String;
> > >
> > > We seem to copy memory really too much...
> >
> > Not sure I get these results: assuming a "hello world" application reads
> > only, why is 80% of the time spent writing?
>
> Most of the executed code in the table is what it takes for the system java
> class loader to find and load hello world application class. I think many of
> those java.io.ByteArrayOutputStream.write calls are used in JAR files
> manifest parser which writes to memory byte by byte. Maybe there are other
> places too.
>
> --
> Gregory
>

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