Category: Committed Code

the md5(1) utility on DragonFly now does SHA512 checksums, thanks to Rimvydas Jasinskas.  You can see it as a separate ‘sha512’ binary in /sbin, but it’s a hard link back to the original md5, if I’m reading the commit right.

If you run ‘top -M‘, CPU states are reported on a per-CPU basis.  It turns out that having over 110 CPUs will cause a segmentation fault – but not any longer!  I wish I had a screenshot for this.

If your DragonFly-current system was built between December 6th and 10th, you should upgrade.  There’s a memory corruption bug that may bite you otherwise – but it only existed for those 4 days.

This is not as catastrophic as it may seem.  I did not know this, but there’s a utility called dm(8), for Dungeon Master, used to control game access on a BSD system.  It’s now gone on DragonFly, since its controls aren’t needed, and its setuid ability definitely isn’t needed.

Thanks to Rimvydas Jasinskas, it’s possible to ‘make NOSHARED=yes buildworld‘ and build a complete DragonFly world without shared libraries.

If you happen to be running an old version of DragonFly, you may need to do an intermediate upgrade to move to releases after 5.0.  This is in part because of commits to support C++14.  This only applies to version of DragonFly before 4.4.

There’s several ‘lockmgr’ test programs in DragonFly that can be used to test locking performance.  Matthew Dillon used them recently to test some locking optimizations.

Welcome new DragonFly committer, Peeter Must!

Do you have a terabyte or more of RAM?  You can boot DragonFly.  In theory over 32 terabytes will require changes – but oh, to have such problems…

rdist has been removed.  Does anyone mind?  I don’t think so.

sys_pipe has been modified to avoid contention on DragonFly, which means better performance as tasks get handed between processors.  See the commit message for details.

Matthew Dillon has added KVABIO, an API for avoiding the need to sync the TLB across all CPUs before continuing.  What’s this mean?  The more CPUs you are dealing with, the longer it takes to make sure all of them have the same cached view of the virtual memory.   There’s a tradeoff – caching that view speeds up memory access, but the time cost of the synchronization can erase those benefits.

This API is now supported for NVMe and swap, HAMMER2, and tmpfs.  Note that those last two links show a huge drop in IPI messaging.  In the real world, this showed about a 5% improvement in performance for CPU-intensive work like complete synth builds.  (Based on IRC conversations.)

The ppp kernel module has been removed.   It’s still possible to run ppp(8) in userland, with tun(4), so it’s only a change in strategy, not result.

This is a bugfix release, adding HAMMER2 support in initrd, among other cleanup commits.  The tag message lists the changes.  There’s no huge changes, but it’s only a bugfix release.

I’ve got a long backlog of things to link to, so here’s the start: ifconfig now has an ‘lscan’ option, to show long SSIDs.  “Long” means 14+ characters, in this case.

(Can you use emoji to create a SSID?  That breaks character count and it’s just plain hard to read.  Hmm.)