Re: [PATCH] percpu: add optimized generic percpu accessors

From: David Miller
Date: Wed Jan 21 2009 - 15:34:29 EST


From: Stephen Hemminger <shemminger@xxxxxxxxxx>
Date: Wed, 21 Jan 2009 23:45:01 +1100

> This is crap. only a small fraction of these SNMP counters are
> close enough to the hot path to deserve per-cpu treatment.

Only if your router/firewall/webserver isn't hitting that code path
which bumps the counters you think aren't hot path.

It's a micro-DoS waiting to happen if we start trying to split
counters up into groups which matter for hot path processing
(and thus use per-cpu stuff) and those which don't (and thus
use atomics or whatever your idea is).
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