From mboxrd@z Thu Jan 1 00:00:00 1970 From: Frederic Weisbecker Date: Thu, 24 Sep 2020 14:09:57 +0200 Subject: [Intel-wired-lan] [PATCH v2 1/4] sched/isolation: API to get housekeeping online CPUs In-Reply-To: <20200924084029.GC1362448@hirez.programming.kicks-ass.net> References: <20200923181126.223766-1-nitesh@redhat.com> <20200923181126.223766-2-nitesh@redhat.com> <20200924084029.GC1362448@hirez.programming.kicks-ass.net> Message-ID: <20200924120956.GA19346@lenoir> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: intel-wired-lan@osuosl.org List-ID: On Thu, Sep 24, 2020 at 10:40:29AM +0200, peterz at infradead.org wrote: > On Wed, Sep 23, 2020 at 02:11:23PM -0400, Nitesh Narayan Lal wrote: > > Introduce a new API hk_num_online_cpus(), that can be used to > > retrieve the number of online housekeeping CPUs that are meant to handle > > managed IRQ jobs. > > > > This API is introduced for the drivers that were previously relying only > > on num_online_cpus() to determine the number of MSIX vectors to create. > > In an RT environment with large isolated but fewer housekeeping CPUs this > > was leading to a situation where an attempt to move all of the vectors > > corresponding to isolated CPUs to housekeeping CPUs were failing due to > > per CPU vector limit. > > > > Signed-off-by: Nitesh Narayan Lal > > --- > > include/linux/sched/isolation.h | 13 +++++++++++++ > > 1 file changed, 13 insertions(+) > > > > diff --git a/include/linux/sched/isolation.h b/include/linux/sched/isolation.h > > index cc9f393e2a70..2e96b626e02e 100644 > > --- a/include/linux/sched/isolation.h > > +++ b/include/linux/sched/isolation.h > > @@ -57,4 +57,17 @@ static inline bool housekeeping_cpu(int cpu, enum hk_flags flags) > > return true; > > } > > > > +static inline unsigned int hk_num_online_cpus(void) > > This breaks with the established naming of that header. I guess we can make it housekeeping_num_online_cpus() ?