mechanical-sympathy

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Welcome to the Mechanical Sympathy group. This group is for discussing how to code sympathetically for the underlying stack/platform so good performance can be extracted.

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Steven Stewart-Gallus, Richard Startin5

1/28/19

Do modern JVMs use aliasing information?

Ahah! I believe I might have a possible hacky workaround! Instead of doing: static void mul(int[]

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Do modern JVMs use aliasing information?

Ahah! I believe I might have a possible hacky workaround! Instead of doing: static void mul(int[]

1/28/19

Mark E. Dawson, Jr., … Gil Tene6

8/29/18

jHiccup for .NET?

If the .NET profiler api can be used to launch a managed code thread without modifying the

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CoordinatedOmission

feedback-requested

jHiccup for .NET?

If the .NET profiler api can be used to launch a managed code thread without modifying the

8/29/18

Ruslan Cheremin, … Gil Tene16

3/30/19

Avoid stepping on page faults while writing to MappedByteBuffer

On Saturday, March 30, 2019 at 10:17:15 AM UTC-7, Steven Stewart-Gallus wrote: I feel like this is

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Avoid stepping on page faults while writing to MappedByteBuffer

On Saturday, March 30, 2019 at 10:17:15 AM UTC-7, Steven Stewart-Gallus wrote: I feel like this is

3/30/19

Ionut Balosin, Vitaly Davidovich2

5/6/18

Varargs vs. explicit param method call

Your understanding of how varargs calls are made is correct - it's nothing more than sugar for an

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Varargs vs. explicit param method call

Your understanding of how varargs calls are made is correct - it's nothing more than sugar for an

5/6/18

yang liu, … Nitsan Wakart4

9/28/17

jvm stuck in SafepointSynchronize::begin()

Thanks Alex! For future reference to all here: AFAIK lightweight-java-profiler has never progressed

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jvm stuck in SafepointSynchronize::begin()

Thanks Alex! For future reference to all here: AFAIK lightweight-java-profiler has never progressed

9/28/17

Alexandr Nikitin, … Kirk Pepperdine9

6/5/17

Why does the G1 GC shrink number of regions?

On Jun 5, 2017, at 9:02 PM, Gil Tene <g...@azul.com> wrote: On Monday, June 5, 2017 at 9:47:56

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Why does the G1 GC shrink number of regions?

On Jun 5, 2017, at 9:02 PM, Gil Tene <g...@azul.com> wrote: On Monday, June 5, 2017 at 9:47:56

6/5/17

Chris Newland, … Nitsan Wakart6

2/10/17

HotSpot code cache and instruction prefetching

We have no availability based heuristics, nor does anyone else AFAIK, for dynamically enabling/

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HotSpot code cache and instruction prefetching

We have no availability based heuristics, nor does anyone else AFAIK, for dynamically enabling/

2/10/17

Duarte Nunes, … Nitsan Wakart14

2/6/17

Prefetching and false sharing

I'm a bit late to the party, yes JCTools pads 128, this was based on measurement and was visible

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Prefetching and false sharing

I'm a bit late to the party, yes JCTools pads 128, this was based on measurement and was visible

2/6/17

Gaurav Abbi, … Gil Tene5

12/21/16

Does percentile metrics follow the rules of summations?

The right way to deal with percentiles (especially when it comes to latency) is to assume nothing

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SequentialConsistency

Does percentile metrics follow the rules of summations?

The right way to deal with percentiles (especially when it comes to latency) is to assume nothing

12/21/16

Alexey Pirogov, … Steve Gury8

12/12/16

Profiling using hardware counters on Mac OS X

If you're ok with disabling macOS kernel security (loading only signed kernel module), you can

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Profiling using hardware counters on Mac OS X

If you're ok with disabling macOS kernel security (loading only signed kernel module), you can

12/12/16

Miron Aseev, Avi Kivity3

9/18/16

Batching strategies in Netty

Yeah, I think you're right. I'm going to create a topic on the Netty mailing list. Thanks. On

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Batching strategies in Netty

Yeah, I think you're right. I'm going to create a topic on the Netty mailing list. Thanks. On

9/18/16

Dain Ironfoot, … Gil Tene9

7/10/16

Making sense of Memory Barriers

Gil, thank you so very much! I think I speak on behalf of a lot of developers that this is pure gold.

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Making sense of Memory Barriers

Gil, thank you so very much! I think I speak on behalf of a lot of developers that this is pure gold.

7/10/16

Remko Popma, … Anthony Maire55

6/7/16

Garbage-free Log4j docs preview

On Friday, May 27, 2016 at 12:00:44 AM UTC+9, Kirk Pepperdine wrote: Hi Remko, A simple way to start

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Garbage-free Log4j docs preview

On Friday, May 27, 2016 at 12:00:44 AM UTC+9, Kirk Pepperdine wrote: Hi Remko, A simple way to start

6/7/16

Sumit Srivastava, ymo2

2/25/16

Time bounded code section, without threads

Assuming you have multiple computing threads and one collector thread. All you need is : 1) a

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Time bounded code section, without threads

Assuming you have multiple computing threads and one collector thread. All you need is : 1) a

2/25/16

Attila-Mihaly Balazs, … Aleksey Shipilev39

4/1/16

Surprising result when copying arrays of primitives

Thank you all for your great input and I'm looking forward to a new build encompassing all these

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Surprising result when copying arrays of primitives

Thank you all for your great input and I'm looking forward to a new build encompassing all these

4/1/16

Jean Dagenais, … Jean-Philippe BEMPEL23

1/6/17

Systematic Process to Reduce Linux OS Jitter

Hi, Those servers seem nice, but there is a huge no-go for us and our workload: There is only one

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Systematic Process to Reduce Linux OS Jitter

Hi, Those servers seem nice, but there is a huge no-go for us and our workload: There is only one

1/6/17

Vladimir Ozerov, … Jan van Oort8

12/10/14

JNI performance question.

Thank you all for your answers. Aleksey, I believe that nothing was wrong with JMH. The method I

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JNI performance question.

Thank you all for your answers. Aleksey, I believe that nothing was wrong with JMH. The method I

12/10/14

Dain Ironfoot, Georges Gomes2

11/19/14

Assembling MPSC using SPSC queues

Hi Disclaimer: Measurements are always preferred. But here are my thoughts: If you create your

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feedback-requested

Assembling MPSC using SPSC queues

Hi Disclaimer: Measurements are always preferred. But here are my thoughts: If you create your

11/19/14

ymo, Nathan Tippy3

7/17/14

lock free based load generator

Hi Nathan. I found that in a load simulator environments i need to run a set of tests in a tight loop

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CoordinatedOmission

lock free based load generator

Hi Nathan. I found that in a load simulator environments i need to run a set of tests in a tight loop

7/17/14

Alex Rothberg, … Chris Newland9

4/27/14

Method Deoptimzations after Warmup

Hi Jimmy, (Apologies to all for the pseudo sales pitch) I've built a free and open source tool

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Method Deoptimzations after Warmup

Hi Jimmy, (Apologies to all for the pseudo sales pitch) I've built a free and open source tool

4/27/14

4/24/14

JDK Performance Regression Data

Are there any good source of JDK performance metrics (as measured by some benchmark suite) for

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JDK Performance Regression Data

Are there any good source of JDK performance metrics (as measured by some benchmark suite) for

4/24/14

Denis Orlov, … Rüdiger Möller7

4/10/14

Detecting cause of java app freezing

Just as a blind shot: I have had similar issues caused by stream redirection to an external python

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ResponseTimeMeasurement

Detecting cause of java app freezing

Just as a blind shot: I have had similar issues caused by stream redirection to an external python

4/10/14

Nathan Tippy, … Peter Lawrey8

3/20/14

Supporting mixed sequence of Ints and longs in Java/Android

Afaik android doesn't have intrinsics for ByteBuffer / Unsafe. This should impact performance. On

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Supporting mixed sequence of Ints and longs in Java/Android

Afaik android doesn't have intrinsics for ByteBuffer / Unsafe. This should impact performance. On

3/20/14

Gleb Smirnov, … Nitsan Wakart34

7/27/15

JMH vs Caliper: reference thread

JMH has one type of load which is "All-out", it is very deterministically all out. You can

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JMH vs Caliper: reference thread

JMH has one type of load which is "All-out", it is very deterministically all out. You can

7/27/15

Andriy Plokhotnyuk, … Nitsan Wakart3

1/8/14

SALSA: Scalable and Low Synchronization NUMA-aware Algorithm for Producer-Consumer Pools

For lazy people who dont' want to reda the whole thing to find out what Martin meant ;-) "

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SALSA: Scalable and Low Synchronization NUMA-aware Algorithm for Producer-Consumer Pools

For lazy people who dont' want to reda the whole thing to find out what Martin meant ;-) "

1/8/14

Rajiv Kurian, … Peter Lawrey7

12/24/13

Object pooling on the JVM?

Thanks everyone.

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Object pooling on the JVM?

Thanks everyone.

12/24/13

Rajiv Kurian, … Juergen Donnerstag8

11/23/13

True zero copy writes to a socket in linux

UDT is interesting. Thanks.

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True zero copy writes to a socket in linux

UDT is interesting. Thanks.

11/23/13

Rüdiger Möller, … Jean-Philippe BEMPEL12

11/10/13

Wierd Performance Difference between int and long ...

Thanx for your clarification Jean, I am impressed :-) Am Donnerstag, 7. November 2013 21:18:24 UTC+1

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Wierd Performance Difference between int and long ...

Thanx for your clarification Jean, I am impressed :-) Am Donnerstag, 7. November 2013 21:18:24 UTC+1

11/10/13

Eugene Morozov, … Martin Grajcar12

10/15/13

Forward vs backward loop over array performance

Some more specifics regarding the original forward vs backward. My colleague bind my loops to the

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PrintCompilation

Forward vs backward loop over array performance

Some more specifics regarding the original forward vs backward. My colleague bind my loops to the

10/15/13

Eugene Morozov, … Rüdiger Möller15

10/9/13

[Wrappers vs Primitives] memory footprints measurements

I totally agree, but nobody in their mind will allow such a changes even on a mid size enterprise

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[Wrappers vs Primitives] memory footprints measurements

I totally agree, but nobody in their mind will allow such a changes even on a mid size enterprise

10/9/13

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