Committed Code – Page 36 – DragonFly BSD Digest

2011/04/022011/04/02

Double buffering in Hammer usually useful

Enabling the vfs.hammer.double_buffer=1 sysctl will greatly improve Hammer performance when you’ve exceeded your memory cache (at a possible slight penalty when you have not) and also speed things up when using live deduplication.

Update: Venkatesh Srinivas says:

“double_buffer makes sense when: 1) you want all CRCs to be checked on reads. 2) you’re running live dedup and care about dedup performance rather than say read-heavy performance; 3) you have swapcache but are often running into the vnode limit in what you can cache.”

So, not always useful.

2011/04/02

binutils, Hammer updates

Sascha Wildner has updated the default version of binutils in DragonFly from 2.17 to 2.21. You’ll want to do a full buildworld on your next upgrade, if you’re running DragonFly 2.9.

Also, Matthew Dillon has made version 6 the default version of Hammer in DragonFly 2.9. Version 6 has improved handling of directory names in some circumstances. Just don’t ask me which, cause I lost track. It’s been a hard day!

2011/03/302011/03/29

Fairq enhancements

If you’re using pf to control how your bandwidth is used, you may want to look at the recent fairq updates from Matthew Dillon. It should perform better now in situations where one traffic group is saturating its available bandwidth. Here’s a handy link that explains this sort of problem, yoinked from IRC.

2011/03/28

Native binutils support for DragonFly

John Marino’s work on getting support for DragonFly ‘natively’ into binutils, upstream, has been successful. Thanks, John!

2011/03/26

Binutils 2.21 added, still optional

Sascha Wildner has added in binutils version 2.21, replacing 2.20. Note that both 2.20 and 2.21 are ‘optional’, so you have to set BINUTILSVER to use them. Otherwise the system defaults to the also-installed binutils 2.17.

2011/03/24

More memoryallocators manpage material

Venkatesh Srinivas has added a new memoryallocators(9) man page, to describe the various memory allocation schemes in DragonFly. It gives descriptions of each and leads off to more man pages.

2011/03/24

libiberty goes byebye

This is the BSD-licensed version of libiberty, which was removed because it didn’t ever actually make it to being a replacement.

2011/03/072011/03/07

pkgsrc current and 2.9, plus shallow pulls

There’s two recent changes for pkgsrc and DragonFly:

DragonFly-current (2.9) now pulls the most recent pkgsrc quarterly release (2010Q4) by default, instead of pkgsrc-current. This means more packages will be working with the default setup, plus pkg_radd and other tools will be pulling the same ‘generation’ of software.
The DragonFly/git version of pkgsrc can now be created as a shallow clone. This means less file history, but also means a much faster download.

2011/03/04

gcc 4.4 now default

Sascha Wildner has changed the default compiler to gcc 4.4. See his commit notes for some details. To my knowledge, we’re the only BSD using this recent a version.

A full buildworld/buildkernel is probably the best strategy. I’ll be rebuilding all the pkgsrc packages for 2.9 using gcc 4.4… This will take at least a week.

2011/02/242011/02/25

Bridge building better

Matthew Dillon’s improved bridging to the point where you can now modify the MAC address of the bridge and most everything, including ARP, will come from it correctly. It’s even possible to bond 2 or more interfaces together, with the side effect of dragonflybsd.org having a lot more bandwidth.

Update: the config for his bonded interfaces has been posted as an example.

Update 2: More notes here.

2011/02/23

Better bridge built

Matthew Dillon has continued his bridge work, with another commit adding various features. Go, read.

2011/02/19

Transparent bridging added

Matthew Dillon has added transparent bridging, mostly to overcome issues with the AT&T DSL modem he’s using. With this non-default feature, IP packets retain the original MAC address when retransmitted through a new interface.

2011/02/15

tmpfs loses the locks

The tmpfs(5) filesystem now runs without multiprocessor locks. Yay! Another hurdle down.

2011/02/152011/02/21

New ps option

ps now has a new option: -R. This lists processes in order by parent/child status, and indents to make it visually clear. It looks like this. I wish someone had done this 15 years ago.

2011/02/14

Assume it’s multiprocessor-safe

As Matthew Dillon notes in a recent post, procedures are now assumed to be MPSAFE (i.e. without the Giant Lock) by default. Any new work should follow this idea, and it doesn’t have to be documented specially. The inverse used to be true, where the code that happened to work without the Lock was rare, and therefore needed to be pointed out. Now, the good result is the norm.

2011/02/12

fork and exit more mpsafe

Matthew Dillon’s made fork() and exit() (mostly) multiprocessor-safe. It’s only two calls, but both are very frequently used. One more step closer to removing the Giant Lock…

2011/02/11

Scheduler updates

Matthew Dillon’s made some scheduler changes, which blogbench tests are showing give the default scheduler better performance under heavy load. It’s a pretty technical writeup, so I’ll just point you at it rather than attempt to summarize.

2011/02/062011/02/06

More Google Code-In work arrives

Samuel J. Greear committed some more code that happened to come from DragonFly/Google Code-In projects. There’s a surprising large amount of code that came from those projects…

2011/02/03

Good news for people with excess memory

Matthew Dillon’s made some changes that will speed up the booting process for people with a ridiculous amount of memory, like 64G. This is x86_64 only, but that should not be a surprise if you think about it.

2011/01/31

Fixes for rxvt, milter-greylist

In case you are using either of those programs, there’s fixes for building/using them.