F16 unusable while writing to pendrive

[Marko Vojinovic]

On Saturday 17 December 2011 19:41:38 Patrick O'Callaghan wrote:
> This looks like a regression. Under F15 when I wrote large files to a
> pendrive, the system would become a little sluggish. Now it essentially
> freezes until the write terminates. What I mean is that the UI is almost
> completely unresponsive; even clicking between two terminal windows is
> so slow that you can see the window contents refresh, followed several
> seconds later by the frame.
> 
> Fully updated F16 with KDE, Intel Core 2 Dual, 4GB RAM, Intel onboard
> graphics. The pendrive is an 8GB Patriot Xporter (a year or two old)
> under USB-2 with no intervening hub.

Oh yes, this is one of my favourities... :-D

There's a very good article at LWN discussing precisely this issue:

   http://lwn.net/Articles/467328/

You wouldn't believe how complicated these things can get... ;-) One would 
naively think "yes, the USB drive is slow, but that shouldn't stop the rest of 
the system from running smoothly". However, when you put into the mix the 
hugemem page allocation, memory fragmentation, contradictory points of view on 
how the kernel should be optimized, etc., it seems that it is quite natural 
that your typical fast 3GHz system with 4GB of RAM grinds to a complete halt 
during a simple write-to-USB-drive operation... :-D

OTOH, it is actually completely outrageous in this day and age, but... ;-)

Best, :-)
Marko