On 6/15/20 4:48 PM, Keller, Jacob E wrote: > >> -----Original Message----- >> From: Nitesh Narayan Lal <[email protected]> >> Sent: Monday, June 15, 2020 1:21 PM >> To: [email protected]; [email protected]; [email protected]; >> [email protected]; Kirsher, Jeffrey T <[email protected]>; >> Keller, >> Jacob E <[email protected]>; [email protected] >> Subject: [Patch v1] i40e: limit the msix vectors based on housekeeping CPUs >> >> In a realtime environment, it is essential to isolate >> unwanted IRQs from isolated CPUs to prevent latency overheads. >> Creating MSIX vectors only based on the online CPUs could lead >> to a potential issue on an RT setup that has several isolated >> CPUs but a very few housekeeping CPUs. This is because in these >> kinds of setups an attempt to move the IRQs to the limited >> housekeeping CPUs from isolated CPUs might fail due to the per >> CPU vector limit. This could eventually result in latency spikes >> because of the IRQ threads that we fail to move from isolated >> CPUs. This patch prevents i40e to add vectors only based on >> available online CPUs by using housekeeping_cpumask() to derive >> the number of available housekeeping CPUs. >> >> Signed-off-by: Nitesh Narayan Lal <[email protected]> >> --- > Ok, so the idea is that "housekeeping" CPUs are to be used for general > purpose configuration, and thus is a subset of online CPUs. By reducing the > limit to just housekeeping CPUs, we ensure that we do not overload the system > with more queues than can be handled by the general purpose CPUs?
Yes. General purpose or the housekeeping CPUs or the non-isolated CPUs. > > Thanks, > Jake > -- Nitesh
signature.asc
Description: OpenPGP digital signature
