Re: Performance problem with GC enabled
Re: Performance problem with GC enabled
- Subject: Re: Performance problem with GC enabled
- From: Bill Bumgarner <email@hidden>
- Date: Thu, 12 Mar 2009 10:54:01 -0700
On Mar 12, 2009, at 10:29 AM, John Engelhart wrote:
Actually, this isn't a "micro-benchmark".
If you aren't displaying the results, responding to user events,
keeping an application state up to date and otherwise doing all of the
things that need be done in a real world application, it is --
effectively -- a micro-benchmark.
In the context of an application, such processing is likely to be on a
secondary thread and there is likely to be synchronization of data
between threads. The overhead of the write barrier (which is spin
lock contention under the covers, most likely) will be somewhat offset
by the vast decrease in the cost of moving objects between threads,
for example.
Think about processing HTTP server logs, and then
performing more regex operations the further massage the end results
(ie, the host only portion of the referrer).
Sure -- and if I were writing a Cocoa application to do exactly that,
it would be doing all kinds of UI updates during the process to keep
the user up to date on progress, give them a feel for whether the
analysis is moving along in the correct direction, etc,etc,etc.... and
all of that graphics related chatter is very likely going to far
outweigh the CPU cycles consumed by the actual data processing bit.
If I were writing a command line tool to process log files in batches
-- which I have done many times on the scale of 10s of GB of logs
produced per day -- I wouldn't use Cocoa or Objective-C at all.
Don't get me wrong -- I'm not saying that you haven't found a
particular test where, at the extreme, there is a significant chunk of
performance cost for using GC vs. Non. And I still want to see the
bug # with binary attached.
b.bum
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