Maoni Stephens

Work flow of diagnosing memory performance issues – Part 2

April 27th, 2020

Work flow of diagnosing memory performance issues – Part 0 Work flow of diagnosing memory performance issues – Part 1 Work flow of diagnosing memory performance issues – Part 2 (this post) In this blog post I’ll talk a bit about how to spend time wisely and then continue with the analysis. Originally I was going to delve de

Work flow of diagnosing memory performance issues – Part 1

April 12th, 2020

Work flow of diagnosing memory performance issues – Part 0 Work flow of diagnosing memory performance issues – Part 1 (this post) Work flow of diagnosing memory performance issues – Part 2 In this blog post I’ll talk a bit about contributing to PerfView and then continue with the GCStats analysis. You can skip to the anal

Work flow of diagnosing memory performance issues – Part 0

April 5th, 2020

Work flow of diagnosing memory performance issues – Part 0 (this post) Work flow of diagnosing memory performance issues – Part 1 Work flow of diagnosing memory performance issues – Part 2 I wanted to describe what I do to diagnose memory perf issues, or rather the common part of various work flows of doing such diagnostics

Helping Customers Effectively

March 30th, 2020

I have to put a disclaimer here since this is not the usual type of blog posts I write. I’m by no means a master at communication. This is just what I thought that seemed to work well. YMMV of course. But I’d be very happy if they help you in some way ‘cause many of us work with customers. And I welcome your thoughts and suggestions. I

Balancing work on GC threads

March 28th, 2020

In Server GC, each GC thread will work on its heap in parallel (that's a simplistic view and is not necessarily true for all phases but on the high level it's exact the idea of a parallel GC). So that alone means work is already split between GC threads. But because GC work for some stages can only proceed after all threads are done with their

Provisional Mode

February 27th, 2020

A coworker asked me what this “PMFullGC” trigger reason he’s seeing in GCStats means. I thought it’d be useful to share the info here.PM stands for Provisional Mode which means after a GC starts, it can change its mind about the kind of GC it’s doing. But what does that mean exactly? So normally when we start a GC, the first things w

Garbage Collection at Food Courts

February 8th, 2020

When I first started working on the GC, my predecessor was explaining the GC tuning to me. I told him that I thought it sounded like how I saw janitors work at food courts (I frequented food courts at the time 😀). And he concurred. What I said was if you observe at a food court, in order to be productive, the janitor tries to collect a siz

GC Handles

February 6th, 2020

A customer asked me about analyzing perf related to GC handles. I feel like aside from pinned handles in general handles are not talked about much so this topic warrants some explanation, especially since this is a user facing feature. For some background info, GC handles are indeed generational so when we are doing ephemeral GCs we only need

GC Perf Infrastructure – Part 1

December 9th, 2019

We open sourced our new GC Perf Infrastructure! It’s now part of the dotnet performance repo. I’ve been meaning to write about it ‘cause some curious minds had been asking when they could use it after I blogged about it last time but didn’t get around to it till now. First of all, let me point out that the target audience of this infr

The history of the GC configs

November 2nd, 2019

Recently, Nick from Stack Overflow tweeted about his experience of using the .NET Core GC configs – he seemed quite happy with them (minus the fact they are not documented well which is something I’m talking to our doc folks about). I thought it’d be fun to tell you about the history of the GC configs ‘cause it’s almost the weekend a