Re: [dpdk-dev] [PATCH] examples/vm_power: fix app to respect max cpus

[Thomas Monjalon <thomas@monjalon.net>]

31/10/2018 12:50, David Hunt:
> The vm_power_manager app was not respecting the POWER_MGR_MAX_CPUS
> during initialisation, so if there were more CPUs than this value (64),
> it would lead to buffer overruns of there were more then 64 cores in
> the system.
> 
> Added in a check during init and un-init to only initialise up to
> lcore_id 63.
> 
> This raises the question as to why not simply increase the value of
> POWER_MGR_MAX_CPUS. Well, it's not that simple, as many of the APIs take
> a uint64_t as a parameter for the core mask, and this will not work for
> cores greater than 63. So some work needs to be done in the future to
> remove this limitation. For now we'll fix the memory corruption.
> 
> Also, the patch that this fixes says "allow greater than 64 cores" but
> that's not across the entire application, it's only for the out-of-band
> monitoring. I'll add a notice for an API change in the next release to
> clean this up, i.e. depricate any API calls that use masks.
> 
> Fixes: 6453b9284b64 ("examples/vm_power: allow greater than 64 cores")
> 
> Signed-off-by: David Hunt <david.hunt@intel.com>

+ Cc: stable@dpdk.org

Applied, thanks