Re: [PATCH net-next 1/2] net: remove NET_LL_RX_POLL config menue

From: Eliezer Tamir
Date: Wed Jun 12 2013 - 22:13:45 EST

On 13/06/2013 05:01, Stephen Hemminger wrote:
On Wed, 12 Jun 2013 15:12:05 -0700 (PDT)
David Miller <davem@xxxxxxxxxxxxx> wrote:

From: Eliezer Tamir <eliezer.tamir@xxxxxxxxxxxxxxx>
Date: Tue, 11 Jun 2013 17:24:28 +0300

depends on X86_TSC

Wait a second, I didn't notice this before. There needs to be a better
way to test for the accuracy you need, or if the issue is lack of a proper
API for cycle counter reading, fix that rather than add ugly arch
specific dependencies to generic networking code.

This should be sched_clock(), rather than direct TSC access.
Also any code using TSC or sched_clock has to be carefully audited to deal with
clocks running at different rates on different CPU's. Basically value is only
meaning full on same CPU.


If we covert to sched_clock(), would adding a define such as HAVE_HIGH_PRECISION_CLOCK to architectures that have both a high precision clock and a 64 bit cycles_t be a good solution?

(if not any other suggestion?)

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