Re: [PATCH v2 2/3] Documentation, ABI: Add a document entry for cache id

From: Ingo Molnar
Date: Fri Jul 08 2016 - 14:08:00 EST

* Luck, Tony <tony.luck@xxxxxxxxx> wrote:

> > It means one cache's id is unique in all caches with same cache index number.
> > For example, in all caches with index3 (i.e. level3), cache id 0 is unique to identify
> > a L3 cache. But in caches with index 0 (i.e. Level0), there is also a cache id 0.
> > So cache id is unique in one index. But not unique in two different index.
> > Does that make sense? I hope I express that correctly.
> We use "index" rather than "level" because that is the terminology used
> in /sys/devices/system/cpu/cpu*/cache/index*

Who can we ... thank for that nonsensical naming? :-/

> E.g. on most Intel cpus you'll typically find "index0" is the L1-data cache,
> "index1" is the L1-instruction cache, "index3" is the L2-unified cache and
> "index4" is the L3-unified cache.

Crazy. What was wrong with using 'level' or 'depth'?