A while back while developing some #SPDK code, I was sorely missing the ability to:

ASSERT(MUTEX_HELD(...))

The more I dug into the intersection of pthread mutexes and SPDK's concurrency model, the more I realized that there was a lot of room for improvement. This all led to SPDK's new spinlock implementation. A blog post with the details is at https://spdk.io/spdk_spinlock/2023/01/04/spdk_lock/.

Much of the new behavior is inspired by #Solaris mutexes.

@parvXm There's some great work done here, which is sorely needed. Having been working on #spdk for a while, I wonder how much benefit there may be message passing such that IO for a particular dataset is always done by the same CPU thread or a very small group of them if that's too much work for one. I'd need to refresh my memory of #zfs internals, but I think this could reduce lock contention and perhaps eliminate some locks.

@b0rk's threads about debuggers made me nostalgic for #mdb on Solaris and illumos. Currently I'm working on #SPDK, which seems to be only supported on Linux and #FreeBSD . Ever so hopeful, I tried:

[mgerdts@freebsd ~/spdk]$ mdb ./test/unit/lib/bdev/bdev.c/bdev_ut
mdb: no target ctor: No error: 0

😦

That's probably a pretty big hint that there is much #yakShaving to do to get the to level of functionality I'd want. Prolly better to write some gdb commands in python.

Huh. Somehow I’m first on the list of speakers at the SPDK Virtual Summit 2022. The pressure! If you are interested in #SPDK this is the place to be in a couple weeks.

https://web.cvent.com/event/62e99886-2706-4bf8-96d8-6a20fe9822ae/websitePage:a0ada8a8-dce5-4918-af1a-b135cf661092

What better #introduction to #fosstodon than a look at what I think was my first #foss contribution. I’d like to apologize now for the unbounded memory allocation bug I introduced. Oops.

https://github.com/php/php-src/commit/72f675be5005f09c048155b85b5d6efd7341f6e0

Since then I’ve done a bunch of #sysadmin work (mostly #Solaris) followed by OS (#solaris #illumos #smartos #zfs) development and more recently various storage stuff (#nvme #nvmeof #roce #spdk #bluefield #dpu #smb).

I love #hiking through the #wilderness and other natural areas.