Messages in this thread | | | Date | Thu, 28 Mar 1996 10:43:34 -0700 | From | Nelson Minar <> | Subject | Re: Kernel errors in 1.3.78 |
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Rani Chouha <rani@smartec.com> writes: >Hi, I just upgraded my kernel to 1.3.78 and whenever I type 'ps ux' >or 'top' I get the error: Floating point exception. >Any idea why?
Yeah, this is the latest memory optimization in Linux. It used to be that when you allocated memory, you had to either use the whole byte or none of it. But that wastes crucial storage! So now, Linux memory management includes the ability to only use fractional bytes. For example, my X server right now is taking up 49163253.375 bytes of memory. The .375 is an extra 3 bits it needs.
The really cool thing is that if you write your code correctly, you can even use fractional bits. For instance my new ray tracer is using something like 132935.5416666666... bytes right now. The fractional component indicates I'm using 4 and 1/3 bits. This is very valuable: the other 3 and 2/3 bits are available to the kernel for allocation as cache, to other processes, etc.
There are still some bugs in the process (hey, this is a new kernel feature, afterall). The floating point exceptions are actually occurring in the kernel but somehow are passing outside to ps.
Could someone put this answer in the FAQ please? Thanks.
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