“Grown-up” Chinese Jedi Elsa

Holy moly … CellSpex has the best, most eloquent (scathing) review of Disney’s live-action Mulan. Period. It starts with a hilariously satirical summary and goes on to dissect the maelstrom of bad decisions the film displays with its story adaptation (both from the folk tale as well as the Disney animated movie), characters, themes, style and production. I agree with each and every point.

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Tony Abbott and Tap Water

What could go wrong if-as a joke-your being asked if you could hack the former prime minister of Australia Tony Abbott? Well Alex Hope has documented it. Finding pictures of boarding pass he could log into the booking system of the airline (without additional authentication). Then he found out that the systems leaked sensitive information (passport number, telephone number, airline-internal comments about the passenger). He then went through the whole charade of finding someone in government responsible for concrete data security issues. 😵

There’s even an interesting section on when he finally gets through to Tony Abbot and they talk on a very personal level. Given the reason they were talking in the first place it also revolved about how complicated technology seems to be and how you learn how it works.

This lead Alex to reflect about how he started learning things and how you have to change your thinking when you are “hacking.” He gives a great example which he summarizes with:

In conclusion, to be a hacker u ask for tap water.


Usefulness of Swap Explained

Chris Down explains how swap’s main role is being the missing backing store for anonymous (i.e. allocated by malloc) pages. While all other kinds of data (e.g. paged-in files) can be reclaimed easily and later reloaded, because their “source of truth” is elsewhere. There’s no such source for anonymous pages hence these pages can “never” be reclaimed unless there’s swap space available (even if those pages aren’t “hot”).

Linux has historically had poor swap (and by extension OOM) handling with few and imprecise means for configuration. Chris describes the behavior of a machine with and without swap in different scenarios of memory contention. He thinks that poor swap performance is caused by having a poor measure of “memory pressure.” He explains how work on cgroups v2 might give the kernel (and thus admins) better measures for memory pressure and knobs for dealing with it.