[vox-tech] lame question on memory allocation

[Peter Jay Salzman]

you'd think by now i'd know stuff like this.  i'm embarrased to have to
ask this, but here it goes.

i'm reading the man page for electric fence, and i'm not fully
understanding the sections on EF_ALIGNMENT and "WORD-ALIGNMENT AND
OVERRUN DETECTION".   i feel like i "almost" understand them.

i think i understand the concept of memory page as being the minimum
chunk of memory the kernel handles internally (8192 bytes minimum
allocation of memory on x86) and alignment, but i guess i don't know
what a word is.

for example, the man page says that malloc() may be required to return
word aligned memory pages, so in the diagram:


         1 page allocated by malloc()
x       ------------
x+1     |          |
x+2     | 8192     |
        | bytes on |
        |   x86    |
        |          |
        ------------

i guess that places a restriction on what "x" is, but because i don't
know what a word is, i don't know what that restriction is.

what's a word?  :)

or does it mean that there's a restriction on *size* of the page and not
the starting point?

pete

-- 
First they ignore you, then they laugh at you, then they fight you,
then you win. -- Gandhi, being prophetic about Linux.

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