@mwl after this change: https://github.com/freebsd/pkg/commit/83243c7894afd319f009cc9135cc461767deea35 and thanks to #valgrind's massif tool, in a reference jail I used with LOTS of packages (including many package with plenty of files) the maximum memory peak for a pkg upgrade went from 1.4GB down to 199MB!

#NetBSD peeps! There is a (mostly) working #Valgrind implementation for NetBSD at https://github.com/paulfloyd/valgrind-netbsd. It would be great if we could get a (binary) package for it!

I've done the first version of my slides for FOSDEM. Now I need to practise my speach and see how many of the slides fit in.

#valgrind #OpenBSD #NetBSD #dragonflybsd

Valgrind takes just over 24 hours to run through something in Darknet/YOLO.

Then it prompts once for every single issue it found. 7182 records:

==1747473== ---- Print suppression ? --- [Return/N/n/Y/y/C/c] ----

- Is there a difference between uppercase and lowercase?
- I can guess what "n" and "y" means, but what is "c"? Cancel? Continue?

This is not a time to start experimenting since it took me over 24 hours to get to this stage, and I cannot find the answer in the valgrind docs. #cpp #valgrind

Overhelming! All those tools around building software. #Jenkins, #Github actions, #Valgrind, #Docker, #Docross, #Qemu, and what the heck more. But unfortunately all of them waay too complex and feature-bloated for my taste. In addition, I'm absolutely NOT a fan of #SaaS. But what's the alternative then? ...

Read more:
https://hiddenalpha.ch/slnk/id/1-x0VwNWaFCdXy6kl3

#SelfHosting #Virtualization #BuildEnv #Qemu #Container #Linux #BuildServer

Today's bug is a minor `valgrind` build system bug: https://bugs.kde.org/show_bug.cgi?id=511972

There `valgrind` probed at `./configure` time presence of `-W${flag}` support in `gcc` and used `-Wno-${flag}` to disable it. And it worked until https://gcc.gnu.org/git/?p=gcc.git;a=commitdiff;h=5b276d38c2fdd7df3d167755940da2038e049308

`gcc-16` will not allow countering `-Walloc-size-larger-than=42` with `-Wno-alloc-size-larger-than=42` any more. It has to be spelled as `-Wno-alloc-size-larger-than`.

#bug #valgrind

The FUTO July 2023 Microgrants Picks: Valgrind, KeePassXC, Oobabooga, and Neovim!

https://peertube.futo.org/videos/watch/4fbdd1e1-6b0d-47f3-b6a9-a161e79c4a3a

This looks exciting. GO runtime: add valgrind instrumentation https://go-review.googlesource.com/c/go/+/674077

#valgrind

🎉 Wow, #Go added #Valgrind support! Now you can safely ignore memory leaks while you try to remember why you enabled #JavaScript just to read about it. 🙄🔍
https://go-review.googlesource.com/c/go/+/674077 #support #memoryleaks #HackerNews #HackerNews #ngated

Go has added Valgrind support

https://go-review.googlesource.com/c/go/+/674077

#HackerNews #Go #Valgrind #Support #GoLang #Development #SoftwareEngineering #Programming #Tools

the idris2 docs suggest that a char* returned from an FFI will be `free`'d right away after making another copy.

the #ChezScheme docs do not explicitly state that (and I think idris2 is relying on chez scheme to do this), and #valgrind seems to suggest not.

#Valgrind is such an important tool. Especially when working with c libraries. Great work on #ghostty getting #gtk actually function for it. 😅
https://mitchellh.com/writing/ghostty-gtk-rewrite

🌗 Ghostty GTK 應用程式重寫：擁抱 GObject 系統與 Valgrind 驗證
➤ Zig 與 GTK 的深度整合：一場關於記憶體安全與系統設計的實踐
✤ https://mitchellh.com/writing/ghostty-gtk-rewrite
本文詳述了 Ghostty 終端機模擬器 GTK 版本重寫的技術細節。作者 Mitchell Hashimoto 深入探討瞭如何運用 Zig 語言與 GObject 系統進行整合，並強調了使用 Valgrind 工具對整個應用程式進行徹底記憶體驗證的重要性。重寫後的 Ghostty 應用程式展現了更高的穩定性、功能豐富度與可維護性，並成功解決了先前版本中因 C ABI 封裝而產生的記憶體安全問題。
+ 很高興看到作者如此細緻地分享重寫過程中的技術挑戰與心得，特別是關於 GObject 系統與 Zig 的整合，這對許多跨語言開發者來說非常有啟發性。
+ Valgrind 在 GTK 應用程式中的應用確實是一項艱鉅的任務，但成果斐然。
#軟體開發 #終端機模擬器 #Zig #GTK #GObject #Valgrind

🚀 Wow, rewriting #Ghostty with #Zig and #GObject is like knitting a sweater with spaghetti - impressive, but why? 🤔 Meanwhile, using #Valgrind to verify memory is just a fancy way of saying "I found #bugs in my own code, again." 🍝💻
https://mitchellh.com/writing/ghostty-gtk-rewrite #programming #HackerNews #ngated

You also know you're making progress when valgrind output looks like this:

==32514== All heap blocks were freed -- no leaks are possible
==32514==
==32514== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0)

Stay tuned, later in the day I'll show you current project status 😉

#c #programming #cprogramming #valgrind

Say what you want but GDB and Valgrind are invaluable pieces of my c programming arsenal 😎

#gdb #valgrind #cprogramming #c #freesoftware #foss

#Valgrind https://valgrind.org not only tweaks your instruction stream it also wraps all your system calls so it knows all (memory) manipulation that goes on in your program (and to hide itself from the program it is running inside).

We integrated the #LTP https://linux-test-project.readthedocs.io syscalls testsuite with make ltpchecks

We are now down to ~50 failures https://builder.sourceware.org/testrun/fca661c30befd4e15b1b28e254a20c4d6420826a?amtestdir=ltp%2Ftests&filter_res=FAIL&perPage=50

All tracked in the meta bug dependency tree https://bugs.kde.org/showdependencytree.cgi?id=506971

Lets bring that count down to zarro boogs!

Next #swad release will still be a while. 😞

I *thought* I had the version with multiple #reactor #eventloop threads and quite some #lockfree stuff using #atomics finally crash free. I found that, while #valgrind doesn't help much, #clang's #thread #sanitizer is a very helpful debugging tool.

But I tested without #TLS (to be able to handle "massive load" which seemed necessary to trigger some of the more obscure data races). Also without the credential checkers that use child processes. Now I deployed the current state to my prod environment ... and saw a crash there (only after running a load test).

So, back to debugging. I hope the difference is not #TLS. This just doesn't work (for whatever reason) when enabling the address sanitizer, but I didn't check the thread sanitizer yet...

TIL: calling munmap() with wrong parameters can cause really strange occasional crashes in #AddressSanitizer or #Valgrind. Wrong parameters meaning in this case:
- passing wrong (too large) size,
- passing NULL,
- calling munmap() multiple times for the same pointer.

Debugging the crashes was painful. What helped in the end was "doing the boring right thing": adding error checking to all related system calls, adding debug logs, fixing code smells.

#softwareDevelopment #Linux #mmap