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    Monday, 04 June 2012

    Small children on long-haul flights...

    ...should be banned. On the flight back from Hong Kong to London, a collection of about half a dozen small children conspired to cry, shout, wail and shriek nigh-on constantly. For twelve hours. :-(

    I think it's incredibly selfish to take kids on planes when they're too young to understand what's going on, or to behave reliably. Children make noise, that's natural and expected. Forcing hundreds of other people around you to deal with that noise in an enclosed space for extended periods with no way to escape is just wrong, in my opinion.


    22:20 :: # :: /travel :: 21 comments

    Wandering around Hong Kong

    Jo and I flew in to HK a few days early for the Linaro conference, so we got some time to ourselves for doing touristy stuff. That was a good plan - we got to see quite a lot of Kowloon for a couple of days, then we wandered over to Hong Kong island itself for a day. Jo also had more time during the week while I was in the sessions at the conference.

    Hong Kong is a busy place, very densely packed at all times of day and night that we could see. The first impression we got on the taxi from the airport on day one was that it was a city full of tower blocks - huge numbers of apartments stacked very closely together for living space. That makes sense, I guess, with the large population in such a small space. There are houses around with more space for people to live, but they are understandably very expensive.

    Later on in Kowloon, we got to meet lots of the local street vendors, mostly offering us "Copy Rolex", "Fake handbag" and the like. Even "Sharp trousers" at one point. We decided not to try them out... :-) We saw lots and lots of very expensive shops downtown, crammed into huge shopping centres in the tourist area. As an antidote for all of that, we headed up to the "Golden Computer Arcade" to go browsing around the vast array of tiny technology stalls and shops there. Picked up some nice cheap laptop memory and some SD cards there. Yay!

    Across on Hong Kong island itself on Sunday, we found my grandfather's grave then rode around on the trams for a while to get a good view of the city, including a democracy protest that happened to be on that day! We had a quick look around Tin Hau Temple, where we found a very specific set of rules for visitors:

    temple rules

    I can only guess that they must have been terrified by gangs of kids racing their RC cars at one point!

    We finished the day by heading up to Victoria Peak for the sunset view and some dinner, then back to the hotel. Killing time in a shopping centre waiting for the bus to turn up, we found a truly astonishing little item on sale, a Solar Queen!

    solar queen

    Apparently this gift has a solar panel on the handbag to provide power to a little motor in the Queen's hand to make her wave to her subjects. We decided that we'd somehow have to live without such a delight in our lives... :-)

    HK was a cool place to visit. It still feels very British in some ways, as you'd expect from an ex-colony (power sockets are still the same as ours, driving on the left, everybody spoke English, etc.) but utterly alien in others (the climate, working public transport *grin*). I look forwards to heading out there again!

    22:12 :: # :: /travel :: 0 comments

    Linaro Connect in Hong Kong, 2012: Ruby bug squashed!

    Connect logoSometimes conferences can be dull and boring, but sometimes they can be just awesome in terms of finding the right people to collaborate with. Linaro Connect in Hong Kong last week was definitely one of the great ones!

    I chaired my my usual sessions (armhf status and cross-distro ARM) and we had some lively discussion in both. We're probably just about done with the armhf sessions, as most distros have accepted a hard-float ARMv7 port now and there's not so much specific work left there now that future sessions will be necessary. The cross-distro work for ARM ports is likely to continue into the future, but we're going to be concentrating on bootstrapping work for ARMv8 soon.

    Talking v8, there were a lot of meetings discussing the various work topics for this new 64-bit ARM architecture: kernel, toolchains, bootstrapping etc. More to come on that soon!

    On top of all this useful discussion and planning, we also found time during the week for some hacking. This was the highlight of the week for me, as I found some expert help to solve my long-standing Ruby on ARM bug (Debian bug #652674, ruby1.9.1: FTBFS on armhf: test suite segfaults). Ulrich Weigand (an IBM toolchain wizard seconded into the Linaro team) sat with me for a couple of hours while we worked through reproducing the problem, only to find that he could not reproduce it! The crash had looked very much like a pthreads locking bug, which was scaring me. After some digging, we worked out where the problem was, and how it was now fixed.

    For a long time on ARM, the Linux getcontext/setcontext system calls have never been implemented; apparently nobody really missed them, so they have never been a priority. In Ruby 1.9.x, the implementation of the new "fiber" primitive wanted to use getcontext/setcontext to control stack state etc. in different threads of control. In cases where they are not available or known not to work well, Ruby has fallback code to implement similar functionality. It seems that fallback code is buggy. Maybe it was correct at some point and has bit-rotted due to not being exercised, or maybe it was buggy as written, but it clearly does not work correctly for us now. In the last few months, getcontext/setcontext have finally been implemented for ARM in glibc trunk (by Michael Hope, also in the Linaro toolchain team!) and backported into current Debian and Ubuntu eglibc versions. Re-running configure and rebuilding Ruby against the most recent code in both Sid and Precise fixed the test suite crash we were seeing earlier. Yay! We could also provoke the bug again at will by quickly hacking around the Ruby source to force it to switch back to the fallback code, thereby verifying the fix.

    Why does this matter? As we're expecting ARM servers to enter the market soon, web apps written in Ruby on Rails are going to be an important part of the software stack that customers will want to run. Broken fibers and threading would not help here!

    It's great to meet up and work with talented folks like this; Linaro Connect is an excellent event for getting stuff done!

    20:22 :: # :: /linaro :: 0 comments

    Visiting my grandfather in Hong Kong

    I never met my father's father, as he died many years before I was born. He was a soldier in the British Army and was killed in an accident in Burma in the 1950s. I'm told that back then the Army did not repatriate casualties as a matter of course like they do today, so none of the family got to see his funeral or even visit the grave. Like many of the military casualties in the Far East, he was buried in the Colonial Cemetery in Hong Kong. A few photographs were sent to my grandmother of the ceremony and the headstone, but that's all we ever saw.


    Fast forward to 2012. I travelled to Hong Kong for a conference (Linaro Connect, more about that later...). I looked up the details of where grandad was laid to rest, and found a major coincidence. He was killed on 27th May 1952, almost exactly 60 years ago! I resolved to go to find him on 27th May 2012 to make the most of this lucky anniversary. Wikipedia told me that in the intervening years the Colonial Cemetery had been renamed to Happy Valley Cemetery, then simply Hong Kong Cemetery, and repurposed from military to civilian use.

    Jo and I bought some flowers and headed over to Happy Valley on Hong Kong Island on Sunday afternoon. We found a very large cemetery with a helpful map posted to show the different sections, but nothing to tell us where we should be looking. One of the attendants at the office on site looked at the details we had and shrugged to say "sorry, can't help". Ah well, nobody said this was going to be very easy... What we found after a few minutes was that the graves weren't laid out in any obviously logical fashion. In any given small area, you'd find people buried from roughly the same period, but people for any given period could (and would) be scattered across multiple sections at all corners of the site. Great, time for an exhaustive search then. I started combing the site, checking all the markers I could find that looked anything like the tiny grainy black and white photo we had of grandad's headstone.


    Almost two hours later, I eventually found him. Two hours of heavy work: the cemetery is built on the side of quite a steep hill, and the prevailing weather was very hot with 100% humidity. But, I forgot all that as we eventually stumbled across the correct grave in (no exaggeration!) the very last part of the last section of the site, 20a.


    I was relieved at this point: as things had taken so long, I had started to worry that maybe the grave had been moved or the headstone damaged and lost. But no, I found the man who had gone off to war leaving my dad and aunt as small children. We took some photos and took note of where we had found the final resting place of Sergeant William Alexander McIntyre of the Royal Signals, a man I never met in life but clearly a very important member of our family.

    19:07 :: # :: /misc :: 4 comments