svn commit: r1864 - logback/trunk/logback-core/src/test/java/ch/qos/logback/core/joran
Author: ceki Date: Thu Oct 23 15:13:49 2008 New Revision: 1864 Modified: logback/trunk/logback-core/src/test/java/ch/qos/logback/core/joran/SkippingInInterpreterTest.java Log: - bug hunting Modified: logback/trunk/logback-core/src/test/java/ch/qos/logback/core/joran/SkippingInInterpreterTest.java ============================================================================== --- logback/trunk/logback-core/src/test/java/ch/qos/logback/core/joran/SkippingInInterpreterTest.java (original) +++ logback/trunk/logback-core/src/test/java/ch/qos/logback/core/joran/SkippingInInterpreterTest.java Thu Oct 23 15:13:49 2008 @@ -34,6 +34,7 @@ import ch.qos.logback.core.status.Status; import ch.qos.logback.core.status.StatusManager; import ch.qos.logback.core.util.Constants; +import ch.qos.logback.core.util.StatusPrinter; /** * Test the way Interpreter skips child elements in case of exceptions thrown by @@ -82,6 +83,7 @@ assertEquals(expectedInt, i); } + StatusPrinter.print(context); // check the existence of an ERROR status List<Status> statusList = sm.getCopyOfStatusList(); Status s0 = statusList.get(0);
I'm making a guess, but where I'd be looking is in SLF4J at bogoInstruction. It is using Random to presumably compute the speed of the processor. But many CPUs have optimizations for this while some don't. And the processor's efficiency in computing a random number probably has little to do with most of the work being done in Logback. Just a guess though. Ralph noreply.ceki@qos.ch wrote:
Author: ceki Date: Thu Oct 23 15:13:49 2008 New Revision: 1864
Modified: logback/trunk/logback-core/src/test/java/ch/qos/logback/core/joran/SkippingInInterpreterTest.java
Log: - bug hunting
Modified: logback/trunk/logback-core/src/test/java/ch/qos/logback/core/joran/SkippingInInterpreterTest.java ============================================================================== --- logback/trunk/logback-core/src/test/java/ch/qos/logback/core/joran/SkippingInInterpreterTest.java (original) +++ logback/trunk/logback-core/src/test/java/ch/qos/logback/core/joran/SkippingInInterpreterTest.java Thu Oct 23 15:13:49 2008 @@ -34,6 +34,7 @@ import ch.qos.logback.core.status.Status; import ch.qos.logback.core.status.StatusManager; import ch.qos.logback.core.util.Constants; +import ch.qos.logback.core.util.StatusPrinter;
/** * Test the way Interpreter skips child elements in case of exceptions thrown by @@ -82,6 +83,7 @@ assertEquals(expectedInt, i); }
+ StatusPrinter.print(context); // check the existence of an ERROR status List<Status> statusList = sm.getCopyOfStatusList(); Status s0 = statusList.get(0); _______________________________________________ logback-dev mailing list logback-dev@qos.ch http://qos.ch/mailman/listinfo/logback-dev
Ralph Goers wrote:
I'm making a guess, but where I'd be looking is in SLF4J at bogoInstruction. It is using Random to presumably compute the speed of the processor. But many CPUs have optimizations for this while some don't. And the processor's efficiency in computing a random number probably has little to do with most of the work being done in Logback.
Just a guess though.
I had similar hunch. Checking the code for Random.nextInt(int) on Windows, I see protected int next(int bits) { long oldseed, nextseed; AtomicLong seed = this.seed; do { oldseed = seed.get(); nextseed = (oldseed * multiplier + addend) & mask; } while (!seed.compareAndSet(oldseed, nextseed)); return (int)(nextseed >>> (48 - bits)); } and on Linux, I see protected synchronized int next(int bits) { seed = (seed * multiplier + 0xbL) & ((1L << 48) - 1); return (int) (seed >>> (48 - bits)); } The Linux version of the next(int) method seems lighter and consequently should run faster. Thus, the observed bogoIPS on the Linux machine is higher. I also suspect that my Linux machine is in reality slower because it is older and has a relatively slow AMD CPU. BogoPerf, thinking that the Linux machine is faster, adjusts its numbers in the wrong direction. I will attempt to force BogoPerf to use the same Random.next(int) implementation and see if things improve. -- Ceki Gülcü Logback: The reliable, generic, fast and flexible logging framework for Java. http://logback.qos.ch
participants (3)
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Ceki Gulcu -
noreply.ceki＠qos.ch -
Ralph Goers