I just found out ByteBuffer.allocateDirect is ridiculously slow, that's why the Buffer reuse on Journal made a lot of difference on the performance for us. | final int TIMES = 50; | | final long numberOfIteractions = 1000000; | | | public void testJustAllocateBufferDirect() throws Exception | { | | long start = System.currentTimeMillis(); | | for (int c = 0; c < TIMES; c++) | { | for (long i = 0; i < numberOfIteractions; i++) | { | if (i == 10000) | { | start = System.currentTimeMillis(); | } | MessagingBuffer bufferSend = ChannelBuffers.wrappedBuffer(ByteBuffer.allocateDirect(1024)); | | bufferSend.writeBytes(new byte[1024]); | } | | long spentTime = System.currentTimeMillis() - start; | | System.out.println("Time BuffersDirect = " + spentTime); | } | | } | | public void testOurBuffers() throws Exception | { | | long start = System.currentTimeMillis(); | | for (int c = 0; c < TIMES; c++) | { | for (long i = 0; i < numberOfIteractions; i++) | { | if (i == 10000) | { | start = System.currentTimeMillis(); | } | ChannelBuffer bufferSend = ChannelBuffers.wrappedBuffer(AsynchronousFileImpl.newNativeBuffer(1024)); | | bufferSend.writeBytes(new byte[1024]); | | AsynchronousFileImpl.destroyBuffer(bufferSend.toByteBuffer()); | } | | long spentTime = System.currentTimeMillis() - start; | | System.out.println("Time JBM JNI Buffers = " + spentTime); | } | | On the Above test, ByteBuffer.allocateDirect needed 100 seconds to complete the 1 million buffers. While our code, allocating ByteBuffers directly through JNI, needed 2 seconds to complete 1 million buffers. That *is* ridiculous. The new Buffers were slicing the direct ByteBuffer, what affected the capacity, breaking buffer reuse, what raised this issue to my eyes. I have made a few changes on the Journal, where we will allocate buffers directly, and I could get very good numbers with some simple tests. (Even thought I was not targeting any optimizations.. just looking after this bug on ByteBuffer). We can talk about this tomorrow on the meeting. View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4214338#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...