Mark Hemment wrote:
>
> The original idea behind offset was for objects with a "hot" area
> greater than a single L1 cache line. By using offset correctly (and to my
> knowledge it has never been used anywhere in the Linux kernel), a SLAB
> cache creator (caller of kmem_cache_create()) could ask the SLAB for more
> than one colour (space/L1 cache lines) offset between objects.
>
What's the difference between this definition of 'offset' and alignment?
alignment means that (addr%alignment==0)
offset means that (addr1-addr2 == n*offset)
Isn't the only difference the alignment of the first object in a slab?
> As no one uses the feature it could well be broken, but is that a reason
> to change its meaning?
>
Some hardware drivers use HW_CACHEALIGN and assume certain byte
alignments, and arm needs 1024 byte aligned blocks.
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This archive was generated by hypermail 2b29 : Wed Mar 07 2001 - 21:00:10 EST