[infinispan-dev] Initial LIRS implementation

[Bryan Thompson]

Vladimir,

I believe that there is a lock problem with the BufferedConcurrentHashMap.  This code path does not progress.  What is strange is that this is the only thread in the thread dump that is in BufferedConcurrentHashMap, which suggests a lock ordering problem.  I don't see the problem offhand, but this happens everytime I run our application with the BufferedConcurrentHashMap.

Bryan 

"Thread-3" prio=10 tid=0x00002aafec141000 nid=0x41ba runnable [0x0000000040737000]
   java.lang.Thread.State: RUNNABLE
        at sun.misc.Unsafe.$$YJP$$compareAndSwapInt(Native Method)
        at sun.misc.Unsafe.compareAndSwapInt(Unsafe.java)
        at java.util.concurrent.locks.AbstractQueuedSynchronizer.compareAndSetState(AbstractQueuedSynchronizer.java:526)
        at java.util.concurrent.locks.ReentrantLock$NonfairSync.lock(ReentrantLock.java:183)
        at java.util.concurrent.locks.ReentrantLock.lock(ReentrantLock.java:262)
        at org.infinispan.util.concurrent.BufferedConcurrentHashMap$Segment.remove(BufferedConcurrentHashMap.java:745)
        at org.infinispan.util.concurrent.BufferedConcurrentHashMap$Segment$LRU.execute(BufferedConcurrentHashMap.java:832)
        at org.infinispan.util.concurrent.BufferedConcurrentHashMap$Segment.put(BufferedConcurrentHashMap.java:659)
        at org.infinispan.util.concurrent.BufferedConcurrentHashMap.putIfAbsent(BufferedConcurrentHashMap.java:1421)
        at com.bigdata.cache.BCHMGlobalLRU$InnerCacheImpl.putIfAbsent(BCHMGlobalLRU.java:633)
        at com.bigdata.cache.BCHMGlobalLRU$InnerCacheImpl.putIfAbsent(BCHMGlobalLRU.java:557)
        at com.bigdata.btree.AbstractBTree.readNodeOrLeaf(AbstractBTree.java:3624)

________________________________________
From: Bryan Thompson
Sent: Wednesday, February 03, 2010 5:04 PM
To: Vladimir Blagojevic
Cc: infinispan -Dev List
Subject: RE: [infinispan-dev] Initial LIRS implementation

Vladimir,

Does this match up with what you are seeing?  That is a good win for get()/remove() with a loss on put().

Size = 14698
Performance for container ConcurrentHashMap
Average get ops/ms 13931
Average put ops/ms 306
Average remove ops/ms 294

Size = 452
Performance for container BufferedConcurrentHashMap(LRU)
Average get ops/ms 7735
Average put ops/ms 140
Average remove ops/ms 200

Size = 494
Performance for container BufferedConcurrentHashMap(LIRS)
Average get ops/ms 13400
Average put ops/ms 36
Average remove ops/ms 1136

Bryan

> -----Original Message-----
> From: Vladimir Blagojevic [mailto:vblagoje at redhat.com]
> Sent: Wednesday, February 03, 2010 3:36 PM
> To: Bryan Thompson
> Subject: Re: [infinispan-dev] Initial LIRS implementation
>
> Yes,
>
> Have a look at LRU first and leave LIRS for tomorrow :) I'd
> be happiest if you can find a use case for BCHM+LRU in your
> application and test it out that way. Real life scenario!
>
> Cheers
>
> On 2010-02-03, at 3:27 PM, Bryan Thompson wrote:
>
> > Ah. It is inside the same outer class? Bryan
> >
> >
> >> -----Original Message-----
> >> From: Vladimir Blagojevic [mailto:vblagoje at redhat.com]
> >> Sent: Wednesday, February 03, 2010 2:44 PM
> >> To: Bryan Thompson
> >> Subject: Re: [infinispan-dev] Initial LIRS implementation
> >>
> >> Here it is:
> >> http://fisheye.jboss.org/browse/Infinispan/trunk/core/src/main
> >> /java/org/infinispan/util/concurrent/BufferedConcurrentHashMap.java
> >>
> >> Are you familiar with LIRS? If not, don't bother unless you are
> >> willing to dedicate at least a day or two :(
> >>
> >> http://www.ece.eng.wayne.edu/~sjiang/Projects/LIRS/sig02.ppt
> >> http://citeseer.ist.psu.edu/527790.html
> >>
> >> Regards,
> >> Vladimir
> >>
> >>
> >> On 2010-02-03, at 2:31 PM, Bryan Thompson wrote:
> >>
> >>> Can you send me the full class name and I will check it out. Bryan
> >>>
> >>>> -----Original Message-----
> >>>> From: infinispan-dev-bounces at lists.jboss.org
> >>>> [mailto:infinispan-dev-bounces at lists.jboss.org] On Behalf
> >> Of Vladimir
> >>>> Blagojevic
> >>>> Sent: Wednesday, February 03, 2010 2:09 PM
> >>>> To: infinispan -Dev List
> >>>> Subject: [infinispan-dev] Initial LIRS implementation
> >>>>
> >>>> Hi,
> >>>>
> >>>> I've just committed preliminary attempt to implement LIRS.
> >>>> There does not seem to be serious degradation in terms of
> >> performance
> >>>> when it comes to get/remove commands in comparison with
> >> LRU enabled
> >>>> BufferedConcurrentHashMap.
> >>>> However, put command is about three times slower than in
> >> LRU; put in
> >>>> LIRS is as fast as put command of a single lock
> >> synchronized HashMap.
> >>>>
> >>>> Looking for enthusiasts willing to help out with some code
> >> review :)
> >>>>
> >>>> Regards,
> >>>> Vladimir
> >>>>
> >>>>
> >>>> _______________________________________________
> >>>> infinispan-dev mailing list
> >>>> infinispan-dev at lists.jboss.org
> >>>> https://lists.jboss.org/mailman/listinfo/infinispan-dev
> >>>>
> >>
> >>
>
>