From: Yury Norov <yury.norov@gmail.com>
To: linux-kernel@vger.kernel.org,
"David S. Miller" <davem@davemloft.net>,
Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
Barry Song <baohua@kernel.org>, Ben Segall <bsegall@google.com>,
Dietmar Eggemann <dietmar.eggemann@arm.com>,
Gal Pressman <gal@nvidia.com>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Haniel Bristot de Oliveira <bristot@redhat.com>,
Heiko Carstens <hca@linux.ibm.com>,
Ingo Molnar <mingo@redhat.com>,
Jacob Keller <jacob.e.keller@intel.com>,
Jakub Kicinski <kuba@kernel.org>,
Jason Gunthorpe <jgg@nvidia.com>,
Jesse Brandeburg <jesse.brandeburg@intel.com>,
Jonathan Cameron <Jonathan.Cameron@huawei.com>,
Juri Lelli <juri.lelli@redhat.com>,
Leon Romanovsky <leonro@nvidia.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Mel Gorman <mgorman@suse.de>, Peter Lafreniere <peter@n8pjl.ca>,
Peter Zijlstra <peterz@infradead.org>,
Rasmus Villemoes <linux@rasmusvillemoes.dk>,
Saeed Mahameed <saeedm@nvidia.com>,
Steven Rostedt <rostedt@goodmis.org>,
Tariq Toukan <tariqt@nvidia.com>,
Tariq Toukan <ttoukan.linux@gmail.com>,
Tony Luck <tony.luck@intel.com>,
Valentin Schneider <vschneid@redhat.com>,
Vincent Guittot <vincent.guittot@linaro.org>
Cc: Yury Norov <yury.norov@gmail.com>,
linux-crypto@vger.kernel.org, netdev@vger.kernel.org,
linux-rdma@vger.kernel.org
Subject: [PATCH 6/9] sched/topology: Introduce sched_numa_hop_mask()
Date: Fri, 20 Jan 2023 20:24:33 -0800 [thread overview]
Message-ID: <20230121042436.2661843-7-yury.norov@gmail.com> (raw)
In-Reply-To: <20230121042436.2661843-1-yury.norov@gmail.com>
From: Valentin Schneider <vschneid@redhat.com>
Tariq has pointed out that drivers allocating IRQ vectors would benefit
from having smarter NUMA-awareness - cpumask_local_spread() only knows
about the local node and everything outside is in the same bucket.
sched_domains_numa_masks is pretty much what we want to hand out (a cpumask
of CPUs reachable within a given distance budget), introduce
sched_numa_hop_mask() to export those cpumasks.
Link: http://lore.kernel.org/r/20220728191203.4055-1-tariqt@nvidia.com
Signed-off-by: Valentin Schneider <vschneid@redhat.com>
Reviewed-by: Yury Norov <yury.norov@gmail.com>
Signed-off-by: Yury Norov <yury.norov@gmail.com>
---
include/linux/topology.h | 7 +++++++
kernel/sched/topology.c | 33 +++++++++++++++++++++++++++++++++
2 files changed, 40 insertions(+)
diff --git a/include/linux/topology.h b/include/linux/topology.h
index 72f264575698..344c2362755a 100644
--- a/include/linux/topology.h
+++ b/include/linux/topology.h
@@ -247,11 +247,18 @@ static inline const struct cpumask *cpu_cpu_mask(int cpu)
#ifdef CONFIG_NUMA
int sched_numa_find_nth_cpu(const struct cpumask *cpus, int cpu, int node);
+extern const struct cpumask *sched_numa_hop_mask(unsigned int node, unsigned int hops);
#else
static __always_inline int sched_numa_find_nth_cpu(const struct cpumask *cpus, int cpu, int node)
{
return cpumask_nth(cpu, cpus);
}
+
+static inline const struct cpumask *
+sched_numa_hop_mask(unsigned int node, unsigned int hops)
+{
+ return ERR_PTR(-EOPNOTSUPP);
+}
#endif /* CONFIG_NUMA */
#endif /* _LINUX_TOPOLOGY_H */
diff --git a/kernel/sched/topology.c b/kernel/sched/topology.c
index 2bf89186a10f..1233affc106c 100644
--- a/kernel/sched/topology.c
+++ b/kernel/sched/topology.c
@@ -2124,6 +2124,39 @@ int sched_numa_find_nth_cpu(const struct cpumask *cpus, int cpu, int node)
return ret;
}
EXPORT_SYMBOL_GPL(sched_numa_find_nth_cpu);
+
+/**
+ * sched_numa_hop_mask() - Get the cpumask of CPUs at most @hops hops away from
+ * @node
+ * @node: The node to count hops from.
+ * @hops: Include CPUs up to that many hops away. 0 means local node.
+ *
+ * Return: On success, a pointer to a cpumask of CPUs at most @hops away from
+ * @node, an error value otherwise.
+ *
+ * Requires rcu_lock to be held. Returned cpumask is only valid within that
+ * read-side section, copy it if required beyond that.
+ *
+ * Note that not all hops are equal in distance; see sched_init_numa() for how
+ * distances and masks are handled.
+ * Also note that this is a reflection of sched_domains_numa_masks, which may change
+ * during the lifetime of the system (offline nodes are taken out of the masks).
+ */
+const struct cpumask *sched_numa_hop_mask(unsigned int node, unsigned int hops)
+{
+ struct cpumask ***masks;
+
+ if (node >= nr_node_ids || hops >= sched_domains_numa_levels)
+ return ERR_PTR(-EINVAL);
+
+ masks = rcu_dereference(sched_domains_numa_masks);
+ if (!masks)
+ return ERR_PTR(-EBUSY);
+
+ return masks[hops][node];
+}
+EXPORT_SYMBOL_GPL(sched_numa_hop_mask);
+
#endif /* CONFIG_NUMA */
static int __sdt_alloc(const struct cpumask *cpu_map)
--
2.34.1
next prev parent reply other threads:[~2023-01-21 4:25 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-21 4:24 [PATCH RESEND 0/9] sched: cpumask: improve on cpumask_local_spread() locality Yury Norov
2023-01-21 4:24 ` [PATCH 1/9] lib/find: introduce find_nth_and_andnot_bit Yury Norov
2023-01-21 4:24 ` [PATCH 2/9] cpumask: introduce cpumask_nth_and_andnot Yury Norov
2023-01-21 4:24 ` [PATCH 3/9] sched: add sched_numa_find_nth_cpu() Yury Norov
2023-02-03 0:58 ` Chen Yu
2023-02-07 5:09 ` Jakub Kicinski
2023-02-07 10:29 ` Valentin Schneider
2023-02-17 1:39 ` Yury Norov
2023-02-17 11:11 ` Andy Shevchenko
2023-02-20 19:46 ` Jakub Kicinski
2023-01-21 4:24 ` [PATCH 4/9] cpumask: improve on cpumask_local_spread() locality Yury Norov
2023-01-21 4:24 ` [PATCH 5/9] lib/cpumask: reorganize cpumask_local_spread() logic Yury Norov
2023-01-21 4:24 ` Yury Norov [this message]
2023-01-21 4:24 ` [PATCH 7/9] sched/topology: Introduce for_each_numa_hop_mask() Yury Norov
2023-01-21 4:24 ` [PATCH 8/9] net/mlx5e: Improve remote NUMA preferences used for the IRQ affinity hints Yury Norov
2023-01-21 4:24 ` [PATCH 9/9] lib/cpumask: update comment for cpumask_local_spread() Yury Norov
2023-01-22 12:57 ` [PATCH RESEND 0/9] sched: cpumask: improve on cpumask_local_spread() locality Tariq Toukan
2023-01-23 9:57 ` Valentin Schneider
2023-01-29 8:07 ` Tariq Toukan
2023-01-30 20:22 ` Jakub Kicinski
2023-02-02 17:33 ` Jakub Kicinski
2023-02-02 17:37 ` Yury Norov
2023-02-08 2:25 ` Jakub Kicinski
2023-02-08 4:20 ` patchwork-bot+netdevbpf
2023-02-08 15:39 ` [PATCH 1/1] ice: Change assigning method of the CPU affinity masks Pawel Chmielewski
[not found] ` <CAH-L+nO+KyzPSX_F0fh+9i=0rW1hoBPFTGbXc1EX+4MGYOR1kA@mail.gmail.com>
2023-02-08 16:08 ` Andy Shevchenko
2023-02-08 16:39 ` Yury Norov
2023-02-08 16:58 ` Andy Shevchenko
2023-02-08 19:11 ` kernel test robot
2023-02-09 2:41 ` Philip Li
2023-02-08 19:22 ` kernel test robot
2023-02-08 23:21 ` Jakub Kicinski
2023-02-09 5:14 ` kernel test robot
2023-02-16 14:54 ` [PATCH v2 " Pawel Chmielewski
2023-02-16 15:14 ` Andy Shevchenko
2023-02-16 15:16 ` Andy Shevchenko
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