Re: [PATCH 1/2] perf: Add closing sibling events' file descriptors

[Alexey Budankov]

On 10.08.2020 23:36, Peter Zijlstra wrote:
> On Mon, Aug 10, 2020 at 07:45:18AM -0700, Andi Kleen wrote:
> 
>> Unfortunately we're kind of stuck with the old NFILE=1024 default
>> even though it makes little sense on modern servers.
> 
> Why can't that be changed? It seems to me all of userspace changes all
> the time; heck that system-doofus thing flushed 20+ years of sysadmin
> experience down the drain, just cause. Why can't we up a file limit?
> 

If you asked me I would say that
Intel VTune HW micro architecture analysis would also be unblocked
by pushing RLIMIT_NOFILE limit beyond its current 1K default.

Currently rule of thumb for VTune users is to set the limit to
value == #cores X # events. The recommended value is 64K [1].

BR,
Alexei

[1] https://software.intel.com/content/www/us/en/develop/documentation/vtune-cookbook/top/configuration-recipes/profiling-hardware-without-sampling-drivers.html