Re: Can you run two instances of valgrind on separate nodes in a multi-core NUMA environment?

On Thu, 2024-07-18 at 07:17 +0200, Julian Seward wrote:
> On 18/07/2024 00:00, Tsiang Elaine Reisler wrote:
> > Yes, there is cross-thread synchronization via shared memory, but
> > not
> > cross-process. I am just running helgrind and drd on exactly the
> > same
> > stand-alone program.
> 
> What CPU are you running this on?
> 
> J
Epyc 7513.

I have done some more experiments. It seems the problem is not in
valgrind. Ordinarily I don't pay much attention to NUMA, just run with
whatever defaults. I can succeed in binding the separate valgrinds to
different nodes, but only by chance, if I start them from various
virtual terminals (same with system consoles). As far as what I want to
do at this point, that is a satisfactory solution.

However, trying to bind valgrind explicitly by numactl --cpunodebind
does not work. It starts and runs valgrind through the first segment.
Everyone sounds happy. But afterwards, that process never gets another
robin round. I have no idea - no search results.

Thanks,
Elaine

PS - apologies for the previous redundant post. I got a rejection
notice by sourceforge because I used a different reply-to address than
my send address. Without checking the list, I made another post.