A while ago, I mused on how network latency affects my email usage - one other cause of slowness in my mail client has been GPG key verification. Occasionally, when Evolution wants to check a signature, gpg takes 30 seconds or more to run, and the text of the message is not displayed until the end. The reason gpg runs so slowly is that it sometimes checks its trust database to make sure it's up to date. However, it does not make sense to run this at the time you are trying to verify an email - it will just slow you down. Fortunately, this is very easy to fix - add 'no-auto-check-trustdb' to gnupg.conf, and set up a nightly cronjob to run 'gpg --batch --check-trustdb'. Ensure that you have 'anacron' installed if your system is not always on. ...

Just over a year ago, Greg Kroah-Hartman announced the Linux Driver Project - companies could get Linux drivers written for their hardware free of charge, if they provided specifications (possibly under NDA). There is now an April 2008 Status Report for the project - they are short of companies and hardware to write drivers for. This is probably because Linux hardware support is excellent in all but a few specific areas - there is some interesting discussion of the efforts being made to support wireless devices and graphics cards later on in the thread. (If you're looking to get involved with Linux kernel development, cleaning up greg's LDP git tree would be a good place to start.) ...

I spent my weekend in Cambridge at the Debian bug squashing party. It was good seeing people again. I even squashed a bug, but then spent Saturday forwarding non-RC bugs upstream, and kernel hacking today. :) Walked back to Cambridge station - about 40 minutes, along the river for part of the way, and it was a nice evening. Living where I do, I don't walk as much as I used to... perhaps I should do more at weekends. ...

June 30 - "That's the last day when large computer makers — the Dells, HPs and Lenovos of the world — will be allowed to preinstall Windows XP on new PCs." -- Computerworld story What caught my eye about this was the fact that OEM manufacturers actually won't be allowed to continue installing XP. This seems quite odd to someone used to distributions of GNU/Linux - sure, security support from the distribution might end, and you might well be hard-pushed to find someone to support your seven year-old software, but if your customers want the older, faster version of the operating system, you will always be allowed to sell it.

Lamby reckoned I wouldn't be able to resist using the DebConf8 blog sticker thing. And he was right. My horrendously expensive plane tickets arrived last week.

Yesterday, I was at the first ever PostgreSQL UK conference, in Birmingham. The venue was familiar from various events last year, such as GUADEC and PyCon UK - the Conservatoire is becoming quite established as a relatively cheap, central UK venue for technical events. I gave a talk about monitoring PostgreSQL databases on behalf of credativ. (Slides for all the talks are available on the PostgreSQL wiki.) I got a reasonable level of comments and feedback afterwards, and perhaps those will help with the development of some better monitoring solutions. The act of preparing the talk also let me discover a few different monitoring tools that look useful - perhaps I'll get the chance to look at them at some point. ...

Following up on Saturday's post and various other blog entries about bash. While arguing with Anton about bash being slow, I discovered that /etc/bash_completion was sourced twice when starting a shell on my laptop; once in /etc/bash.bashrc, and once in ~/.bashrc. This is Debian bug #430501 - the suggestion there is that /etc/skel/.bashrc should change to check whether /etc/bash_completion had already been included. So, that saves 0.27 seconds. tim@regulus:~$ time bash -i -c exit exit real 0m0.270s user 0m0.240s sys 0m0.032s ...

Beginning last night, I reinstalled my laptop. Normally, if it were just to clean up some packages, I wouldn't do this - the aim was more to try out removing the disk encryption that I was using, and the effect has been quite dramatic. I worked out a while ago that the device-mapper encryption was slowing down disk access - with it gone, boot times are much shorter (and I don't have to type in a LUKS passphrase). GNOME loads a lot faster. Additionally, bash starts a lot quicker than it did. I suspect loading the bash completion routines takes quite a bit of disk access. Update: No, I just didn't have the bash-completion package installed. Bash is still slow. GNOME is still faster, though... for now. ...

So, a benchmark. tim@regulus:~$ time zsh -i -c exit real 0m0.064s user 0m0.048s sys 0m0.008s tim@regulus:~$ time bash -i -c exit exit real 0m0.540s user 0m0.436s sys 0m0.100s Both shells had their respective completion systems enabled. (Without them turned on, bash actually beats zsh... but the times are small enough that it doesn't matter.) These times are with a warm disk cache - the first time through both shells were slower. And the numbers stay roughly the same when repeating.

Yesterday evening, I finally found the patch for a bug in mono-addins that had been affecting f-spot extensions for a while - rebuilding the f-spot Debian package with no changes and reinstalling would cause the built-in extensions to disappear. In the end, the patch was just two lines long, and had been applied in mono-addins SVN (and in the copy of mono-addins that f-spot bundles). One less RC bug for lenny. ...