Kernel code: executing once on each CPU?

[Martin Cracauer]

Is there a facility in FreeBSD that allows me to have a piece of code
executed on each processor, then return to the original thread when
that has been completed?

I need to collect some data that's local to the individual CPUs/cores.

In Linux there is/was smp_call_function(func, ...).

Martin
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Martin Cracauer <crac...@cons.org> http://www.cons.org/cracauer/
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[Julian Elischer]

Martin Cracauer wrote:
> Is there a facility in FreeBSD that allows me to have a piece of code
> executed on each processor, then return to the original thread when
> that has been completed?
>
> I need to collect some data that's local to the individual CPUs/cores.
>
> In Linux there is/was smp_call_function(func, ...).

no, though it might be useful.

the rmlock facility does this in order to do its work (from memory)
and it would be a useful thing..
I'd even suggest that it take a bitmask of required CPUs.
that can be used in conjuction with the cpu set stuff.

>
> Martin

[Kostik Belousov]

On Tue, Feb 03, 2009 at 12:57:28PM -0500, Martin Cracauer wrote:
> Is there a facility in FreeBSD that allows me to have a piece of code
> executed on each processor, then return to the original thread when
> that has been completed?
>
> I need to collect some data that's local to the individual CPUs/cores.
>
> In Linux there is/was smp_call_function(func, ...).

Look at the smp_rendezvous() in the subr_smp.c. Note that the functions
are called in quite restricted context.