Unfortunately, I had to remove the screensaver hack, because CoolReader became 7 times slower. Specifically, opening Plato's Dialogues (10M fb2 file, 2.8M zip --- don't unzip it!) from cache changed from 6 seconds to 42 seconds which is not tolerable. Of course I tested it properly, i.e. rebooted the Kindle before each open and I repeat --- these are opens from cache, not the FIRST time. I.e. this is the sequence of steps:
0. Install screensaver hack.
1. Open the Plato Dialogues (from litmir.net or any other VERY large fb2) file in CoolReader.
2. Open some other file in CoolReader (so Plato goes to the history list accessible by pressing "l").
3. Exit CoolReader
4. Reboot Kindle
5. Start CoolReader (it will open the small file as it was the last)
6. Press "l" and open Plato from history and measure the time it takes to get to the page.
7. Open some small file (so Plato goes to the history again)
8. Exit CoolReader
9. Reboot the Kindle.
10. Uninstall screensaver hack.
11. Reboot the Kindle again.
12. Go to step 5. above.
With screensaver hack installed the time is 42 seconds. Without it, the time is back to the usual 6 seconds.
I don't know what screensaver hack does (presumably binds some mount points to fool the framework into displaying custom images), but it seems to adversely affect the speed of reading files mapped in via mmap(2) system call (I assume CoolReader still mmaps cache files as it did a few years ago when I played with it while developing djvu viewer for Hanlin V3).
Anyway, something to think about for the brave hacker NiLuJe who wrote this hack.
In the meantime, I will say temporary goodbye to those beautiful pictures of Walther P-38 (my favourite gun) and try to make do with those "poissons" (fishes in french
and silly faces on the standard Amazon screensavers...
Oh btw, can I delete the "linkss" subdirectory in /mnt/us after uninstalling screensaver hack? It is left in there but I like my device clean and tidy with no unnecessary files...