Thanks Alexei for your suggestion, I will try to do it. -----Original Message----- From: Alexei Starovoitov [mailto:alexei.starovoi...@gmail.com] Sent: Monday, October 12, 2020 9:21 AM To: tianxianting (RD) <tian.xiant...@h3c.com> Cc: Alexei Starovoitov <a...@kernel.org>; Daniel Borkmann <dan...@iogearbox.net>; David S. Miller <da...@davemloft.net>; Jakub Kicinski <k...@kernel.org>; Jesper Dangaard Brouer <h...@kernel.org>; John Fastabend <john.fastab...@gmail.com>; Martin KaFai Lau <ka...@fb.com>; Song Liu <songliubrav...@fb.com>; Yonghong Song <y...@fb.com>; Andrii Nakryiko <andr...@fb.com>; KP Singh <kpsi...@chromium.org>; Network Development <net...@vger.kernel.org>; bpf <b...@vger.kernel.org>; LKML <linux-kernel@vger.kernel.org> Subject: Re: [PATCH] bpf: Avoid allocing memory on memoryless numa node
On Sat, Oct 10, 2020 at 1:55 AM Xianting Tian <tian.xiant...@h3c.com> wrote: > > In architecture like powerpc, we can have cpus without any local > memory attached to it. In such cases the node does not have real memory. > > Use local_memory_node(), which is guaranteed to have memory. > local_memory_node is a noop in other architectures that does not > support memoryless nodes. ... > /* Have map->numa_node, but choose node of redirect target CPU */ > - numa = cpu_to_node(cpu); > + numa = local_memory_node(cpu_to_node(cpu)); There are so many calls to cpu_to_node() throughout the kernel. Are you going to convert all of them one patch at a time to the above sequence? Why not do this CONFIG_HAVE_MEMORYLESS_NODES in cpu_to_node() instead? and save the churn.
