Kevin Gosse
@kevingosse.net
Principal engineer at JetBrains, passionate about .NET, performance, and debugging. Microsoft MVP. Co-author of Pro .NET Memory Management (2nd edition)
Today I ran into a deadlock in VS2026. I debugged it, and it turned out to be a common issue you may run into when writing a profiler.
I wrote a short article about it: minidump.net/investigatin...
I wrote a short article about it: minidump.net/investigatin...
Investigating a deadlock in Visual Studio
A short investigation that showcases one of the most common problem faced when writing a profiler.
minidump.net
December 17, 2025 at 5:55 PM
Today I ran into a deadlock in VS2026. I debugged it, and it turned out to be a common issue you may run into when writing a profiler.
I wrote a short article about it: minidump.net/investigatin...
I wrote a short article about it: minidump.net/investigatin...
Visual Studio 2026 18.1.1 has been released. I strongly recommend upgrading if you're using ReSharper, as it fixes an issue that was making startup significantly slower.
Thanks a lot to the VS team for their reactivity!
Thanks a lot to the VS team for their reactivity!
December 17, 2025 at 9:05 AM
Visual Studio 2026 18.1.1 has been released. I strongly recommend upgrading if you're using ReSharper, as it fixes an issue that was making startup significantly slower.
Thanks a lot to the VS team for their reactivity!
Thanks a lot to the VS team for their reactivity!
Reposted by Kevin Gosse
Blogged: Creating a .NET CLR profiler using C# and NativeAOT with Silhouette
andrewlock.net/creating-a-d...
In this post I look at how to create a simple .NET profiler. But instead of using C++, the profiler uses C# and NativeAOT with @kevingosse.net's Silhouette library
#dotnet
andrewlock.net/creating-a-d...
In this post I look at how to create a simple .NET profiler. But instead of using C++, the profiler uses C# and NativeAOT with @kevingosse.net's Silhouette library
#dotnet
Creating a .NET CLR profiler using C# and NativeAOT with Silhouette
In this post I look at how to create a simple .NET profiler. But instead of using C++, the profiler uses C# and NativeAOT with the Silhouette library
andrewlock.net
December 16, 2025 at 6:10 PM
Blogged: Creating a .NET CLR profiler using C# and NativeAOT with Silhouette
andrewlock.net/creating-a-d...
In this post I look at how to create a simple .NET profiler. But instead of using C++, the profiler uses C# and NativeAOT with @kevingosse.net's Silhouette library
#dotnet
andrewlock.net/creating-a-d...
In this post I look at how to create a simple .NET profiler. But instead of using C++, the profiler uses C# and NativeAOT with @kevingosse.net's Silhouette library
#dotnet
I like the peace of mind that @backblaze.bsky.social
is offering, especially after my recent SSD crash. But god, their support is beyond bad. I've contacted them twice, and both times I had to solve the issue myself after a completely unhelpful exchange.
is offering, especially after my recent SSD crash. But god, their support is beyond bad. I've contacted them twice, and both times I had to solve the issue myself after a completely unhelpful exchange.
December 11, 2025 at 8:17 AM
I like the peace of mind that @backblaze.bsky.social
is offering, especially after my recent SSD crash. But god, their support is beyond bad. I've contacted them twice, and both times I had to solve the issue myself after a completely unhelpful exchange.
is offering, especially after my recent SSD crash. But god, their support is beyond bad. I've contacted them twice, and both times I had to solve the issue myself after a completely unhelpful exchange.
There are Mondays, and then there are "the computer doesn't recognize the dev SSD anymore" Mondays.
Samsung 990 Pro 2TB. I tried pretty much everything I could think of, including moving it to a different M2 slot. Suggestions are welcome. The drive doesn't appear in the bios.
Samsung 990 Pro 2TB. I tried pretty much everything I could think of, including moving it to a different M2 slot. Suggestions are welcome. The drive doesn't appear in the bios.
December 8, 2025 at 9:04 AM
There are Mondays, and then there are "the computer doesn't recognize the dev SSD anymore" Mondays.
Samsung 990 Pro 2TB. I tried pretty much everything I could think of, including moving it to a different M2 slot. Suggestions are welcome. The drive doesn't appear in the bios.
Samsung 990 Pro 2TB. I tried pretty much everything I could think of, including moving it to a different M2 slot. Suggestions are welcome. The drive doesn't appear in the bios.
I was investigating a crash, and pasted my windbg output to ChatGPT to see if it could come up with any lead.
It noticed something that I completely missed, a memory area that I dumped in binary was actually a string (even though it's not supposed to be). That's really nice and unexpected.
It noticed something that I completely missed, a memory area that I dumped in binary was actually a string (even though it's not supposed to be). That's really nice and unexpected.
December 2, 2025 at 8:47 AM
I was investigating a crash, and pasted my windbg output to ChatGPT to see if it could come up with any lead.
It noticed something that I completely missed, a memory area that I dumped in binary was actually a string (even though it's not supposed to be). That's really nice and unexpected.
It noticed something that I completely missed, a memory area that I dumped in binary was actually a string (even though it's not supposed to be). That's really nice and unexpected.
Focusing on the Rust Unwrap in the CloudFlare outage is really the scalability equivalent of "When a sage points to the moon, all the fool sees is the finger".
At that scale, failures *will* happen. Programming error are unavoidable. What's interesting is why it took down the entire system.
At that scale, failures *will* happen. Programming error are unavoidable. What's interesting is why it took down the entire system.
November 19, 2025 at 10:56 AM
Focusing on the Rust Unwrap in the CloudFlare outage is really the scalability equivalent of "When a sage points to the moon, all the fool sees is the finger".
At that scale, failures *will* happen. Programming error are unavoidable. What's interesting is why it took down the entire system.
At that scale, failures *will* happen. Programming error are unavoidable. What's interesting is why it took down the entire system.
Fun fact: you can't use print screen to capture a screenshot of a crash of SnippingTool
November 6, 2025 at 8:31 AM
Fun fact: you can't use print screen to capture a screenshot of a crash of SnippingTool
Reposted by Kevin Gosse
#UCP25 | Kevin Gosse - The Hidden Life of Method Calls
Kevin reveals in his session what really happens when your code runs:
➡️ calling conventions
➡️ stack frames
➡️ JIT compilation
➡️ virtual dispatch
➡️ CPU-level mechanics
➡️ prague.updateconf.net
#DotNet #Performance @kevingosse.net @woodruff.dev
Kevin reveals in his session what really happens when your code runs:
➡️ calling conventions
➡️ stack frames
➡️ JIT compilation
➡️ virtual dispatch
➡️ CPU-level mechanics
➡️ prague.updateconf.net
#DotNet #Performance @kevingosse.net @woodruff.dev
November 6, 2025 at 8:11 AM
#UCP25 | Kevin Gosse - The Hidden Life of Method Calls
Kevin reveals in his session what really happens when your code runs:
➡️ calling conventions
➡️ stack frames
➡️ JIT compilation
➡️ virtual dispatch
➡️ CPU-level mechanics
➡️ prague.updateconf.net
#DotNet #Performance @kevingosse.net @woodruff.dev
Kevin reveals in his session what really happens when your code runs:
➡️ calling conventions
➡️ stack frames
➡️ JIT compilation
➡️ virtual dispatch
➡️ CPU-level mechanics
➡️ prague.updateconf.net
#DotNet #Performance @kevingosse.net @woodruff.dev
I had a ton of fun at Techorama NL. It's not everyday that you get a chance to debug variadic .NET functions on a giant movie theater screen.
November 1, 2025 at 9:35 AM
I had a ton of fun at Techorama NL. It's not everyday that you get a chance to debug variadic .NET functions on a giant movie theater screen.
We are getting closer to the release of Resharper 2025.3 , so I ran some performance tests to see how much we improved compared to 2025.2.
For this iteration, I focused my effort mainly on the huge Datadog.Trace solution, available on the DataDog/dd-trace-dotnet repository.
Results below 👇
For this iteration, I focused my effort mainly on the huge Datadog.Trace solution, available on the DataDog/dd-trace-dotnet repository.
Results below 👇
October 30, 2025 at 7:04 PM
We are getting closer to the release of Resharper 2025.3 , so I ran some performance tests to see how much we improved compared to 2025.2.
For this iteration, I focused my effort mainly on the huge Datadog.Trace solution, available on the DataDog/dd-trace-dotnet repository.
Results below 👇
For this iteration, I focused my effort mainly on the huge Datadog.Trace solution, available on the DataDog/dd-trace-dotnet repository.
Results below 👇
I just published a new article: Using profiler function hooks in .NET with Silhouette.
In the process, we also learn how to use static linking with NativeAOT.
minidump.net/using-functi...
In the process, we also learn how to use static linking with NativeAOT.
minidump.net/using-functi...
Using profiler function hooks in .NET with Silhouette
In this article, we see what are function hooks, and how to use them in .NET with Silhouette. We also learn how to statically link a library with NativeAOT.
minidump.net
October 21, 2025 at 11:49 AM
I just published a new article: Using profiler function hooks in .NET with Silhouette.
In the process, we also learn how to use static linking with NativeAOT.
minidump.net/using-functi...
In the process, we also learn how to use static linking with NativeAOT.
minidump.net/using-functi...
Reposted by Kevin Gosse
New blog post:
In 2021 I found an invisible memory leak in a tool (VS Code) that I have never used. Impossible? Easy:
randomascii.wordpress.com/2025/10/09/f...
In 2021 I found an invisible memory leak in a tool (VS Code) that I have never used. Impossible? Easy:
randomascii.wordpress.com/2025/10/09/f...
Finding a VS Code Memory Leak
In 2021 I found a huge memory leak in VS code, totalling around 64 GB when I first saw it, but with no actual limit on how high it could go. I found this leak despite two obstacles that should have…
randomascii.wordpress.com
October 9, 2025 at 8:27 PM
New blog post:
In 2021 I found an invisible memory leak in a tool (VS Code) that I have never used. Impossible? Easy:
randomascii.wordpress.com/2025/10/09/f...
In 2021 I found an invisible memory leak in a tool (VS Code) that I have never used. Impossible? Easy:
randomascii.wordpress.com/2025/10/09/f...
There's an even more adverse effect to the way closures are allocated:
sharplab.io#v2:EYLgxg9gT...
Because the same closure is reused for different calls, you can end up extending the lifetime of some of your objects without realizing it.
sharplab.io#v2:EYLgxg9gT...
Because the same closure is reused for different calls, you can end up extending the lifetime of some of your objects without realizing it.
September 26, 2025 at 1:28 PM
There's an even more adverse effect to the way closures are allocated:
sharplab.io#v2:EYLgxg9gT...
Because the same closure is reused for different calls, you can end up extending the lifetime of some of your objects without realizing it.
sharplab.io#v2:EYLgxg9gT...
Because the same closure is reused for different calls, you can end up extending the lifetime of some of your objects without realizing it.
Top thing I wish I had known earlier as a software engineer: before leaving a company, make sure to download your favorite slack emojis, so you don't have to frenetically look for them on the web when you realize they're missing from the new slack.
September 24, 2025 at 7:18 AM
Top thing I wish I had known earlier as a software engineer: before leaving a company, make sure to download your favorite slack emojis, so you don't have to frenetically look for them on the web when you realize they're missing from the new slack.
Worked at Datadog, encountered crashes because of mysterious race-conditions in .NET writeable metadata: github.com/dotnet/runti...
Moved to JetBrains, encountered crashes because of mysterious race-conditions in .NET writeable metadata: github.com/dotnet/runti...
I think I'm cursed.
Moved to JetBrains, encountered crashes because of mysterious race-conditions in .NET writeable metadata: github.com/dotnet/runti...
I think I'm cursed.
September 22, 2025 at 3:14 PM
Worked at Datadog, encountered crashes because of mysterious race-conditions in .NET writeable metadata: github.com/dotnet/runti...
Moved to JetBrains, encountered crashes because of mysterious race-conditions in .NET writeable metadata: github.com/dotnet/runti...
I think I'm cursed.
Moved to JetBrains, encountered crashes because of mysterious race-conditions in .NET writeable metadata: github.com/dotnet/runti...
I think I'm cursed.
As requested, I published an article about how the UI profiler works: minidump.net/measuring-ui...
It allows me to measure the responsiveness of Visual Studio when running with ReSharper, in various conditions.
I also made the source code available on github: github.com/kevingosse/U...
It allows me to measure the responsiveness of Visual Studio when running with ReSharper, in various conditions.
I also made the source code available on github: github.com/kevingosse/U...
September 18, 2025 at 12:54 PM
As requested, I published an article about how the UI profiler works: minidump.net/measuring-ui...
It allows me to measure the responsiveness of Visual Studio when running with ReSharper, in various conditions.
I also made the source code available on github: github.com/kevingosse/U...
It allows me to measure the responsiveness of Visual Studio when running with ReSharper, in various conditions.
I also made the source code available on github: github.com/kevingosse/U...
Congrats to Microsoft on this new release, I've been using it for a few weeks now and it really feels great.
Note that Resharper is already compatible, if you want to try it!
Note that Resharper is already compatible, if you want to try it!
September 10, 2025 at 7:01 AM
Congrats to Microsoft on this new release, I've been using it for a few weeks now and it really feels great.
Note that Resharper is already compatible, if you want to try it!
Note that Resharper is already compatible, if you want to try it!
Not entirely sure what I'm going to do with all that money.
September 3, 2025 at 10:02 AM
Not entirely sure what I'm going to do with all that money.
I just discovered that whenever you create a closure in a generic C# method, the closure is also generic even when it's not needed.
This is very frustrating to me because generics cause performance issues in Resharper (see bsky.app/profile/kevi...)
sharplab.io#v2:EYLgxg9gT...
This is very frustrating to me because generics cause performance issues in Resharper (see bsky.app/profile/kevi...)
sharplab.io#v2:EYLgxg9gT...
September 1, 2025 at 2:55 PM
I just discovered that whenever you create a closure in a generic C# method, the closure is also generic even when it's not needed.
This is very frustrating to me because generics cause performance issues in Resharper (see bsky.app/profile/kevi...)
sharplab.io#v2:EYLgxg9gT...
This is very frustrating to me because generics cause performance issues in Resharper (see bsky.app/profile/kevi...)
sharplab.io#v2:EYLgxg9gT...
I can't recommend strongly enough to use an unlimited online backup service (I use @backblaze.bsky.social). Backup your whole disk and forget about it.
Just today, I realized I lost some code I wrote months ago (~2 days of work). Painlessly restored it from the automatic backup.
Just today, I realized I lost some code I wrote months ago (~2 days of work). Painlessly restored it from the automatic backup.
August 28, 2025 at 3:14 PM
I can't recommend strongly enough to use an unlimited online backup service (I use @backblaze.bsky.social). Backup your whole disk and forget about it.
Just today, I realized I lost some code I wrote months ago (~2 days of work). Painlessly restored it from the automatic backup.
Just today, I realized I lost some code I wrote months ago (~2 days of work). Painlessly restored it from the automatic backup.
To help reduce the number of UI freezes caused by Resharper, I built an internal tool to measure UI responsiveness.
Here, you can see the improvement between the current 2025.1 version (on the left) and the upcoming 2025.2 version (on the right) with out-of-process enabled.
Here, you can see the improvement between the current 2025.1 version (on the left) and the upcoming 2025.2 version (on the right) with out-of-process enabled.
July 28, 2025 at 12:58 PM
To help reduce the number of UI freezes caused by Resharper, I built an internal tool to measure UI responsiveness.
Here, you can see the improvement between the current 2025.1 version (on the left) and the upcoming 2025.2 version (on the right) with out-of-process enabled.
Here, you can see the improvement between the current 2025.1 version (on the left) and the upcoming 2025.2 version (on the right) with out-of-process enabled.
As I work on Resharper performance, I learn about limitations of .NET (at least, .NET Framework) that I wasn't aware of. Here, I shaved 1 second of CPU time on startup by... removing a call to Array.Empty<T>.
July 23, 2025 at 10:31 AM
As I work on Resharper performance, I learn about limitations of .NET (at least, .NET Framework) that I wasn't aware of. Here, I shaved 1 second of CPU time on startup by... removing a call to Array.Empty<T>.
Working on performance, it's a lot of time wasted on dead-ends and getting the impression of making no progress, and then suddenly managing to shave 10 seconds of CPU time off R# startup.
July 18, 2025 at 3:21 PM
Working on performance, it's a lot of time wasted on dead-ends and getting the impression of making no progress, and then suddenly managing to shave 10 seconds of CPU time off R# startup.