On 06/17/2011 08:11 AM, Andy Green wrote: > On 06/17/2011 01:10 PM, Somebody in the thread at some point said: > > Hi - > >> I've recently become aware that a few packages are causing alignment >> faults on ARM, and are relying on the alignment fixup emulation code in >> the kernel in order to work. > > Just a FYI a lot of later ARM chips are solving alignment fixups in > hardware in the Bus Interface Unit, so the problems won't show up in > kernel stats. > >> Such faults are very expensive in terms of CPU cycles, and can generally >> only result from wrong code (for example, C/C++ code which violates the >> relevant language standards, assembler which makes invalid assumptions, >> or functions called with misaligned pointers due to other bugs). > > Agreed it's usually evidence of something broken and / or evil in the code. > > There is still going to be a small cost even in hardware fixup so this > is very much worth solving despite it's "becoming invisible" because the > chips are hiding / solving it already. >
But I believe that h/w feature is turned off in Linux by default. You have to add noalign to the kernel command line to enable. Rob -- To UNSUBSCRIBE, email to debian-arm-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/4dfba830.8040...@gmail.com
