From: Tianxianting <tian.xianting@h3c.com>
To: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
"David S. Miller" <davem@davemloft.net>,
"Jakub Kicinski" <kuba@kernel.org>,
Jesper Dangaard Brouer <hawk@kernel.org>,
"John Fastabend" <john.fastabend@gmail.com>,
Martin KaFai Lau <kafai@fb.com>,
"Song Liu" <songliubraving@fb.com>, Yonghong Song <yhs@fb.com>,
Andrii Nakryiko <andriin@fb.com>, KP Singh <kpsingh@chromium.org>,
Network Development <netdev@vger.kernel.org>,
bpf <bpf@vger.kernel.org>, LKML <linux-kernel@vger.kernel.org>
Subject: RE: [PATCH] bpf: Avoid allocing memory on memoryless numa node
Date: Mon, 12 Oct 2020 01:26:01 +0000 [thread overview]
Message-ID: <21cff6313475470e9b316911c748f890@h3c.com> (raw)
In-Reply-To: <CAADnVQJUL7BynGMD_nGu8y=D1yv6TybOxeSh03TrkD7kS0aOrA@mail.gmail.com>
Thanks Alexei for your suggestion,
I will try to do it.
-----Original Message-----
From: Alexei Starovoitov [mailto:alexei.starovoitov@gmail.com]
Sent: Monday, October 12, 2020 9:21 AM
To: tianxianting (RD) <tian.xianting@h3c.com>
Cc: Alexei Starovoitov <ast@kernel.org>; Daniel Borkmann <daniel@iogearbox.net>; David S. Miller <davem@davemloft.net>; Jakub Kicinski <kuba@kernel.org>; Jesper Dangaard Brouer <hawk@kernel.org>; John Fastabend <john.fastabend@gmail.com>; Martin KaFai Lau <kafai@fb.com>; Song Liu <songliubraving@fb.com>; Yonghong Song <yhs@fb.com>; Andrii Nakryiko <andriin@fb.com>; KP Singh <kpsingh@chromium.org>; Network Development <netdev@vger.kernel.org>; bpf <bpf@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.xianting@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.
prev parent reply other threads:[~2020-10-12 1:26 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-10 8:44 [PATCH] bpf: Avoid allocing memory on memoryless numa node Xianting Tian
2020-10-12 1:21 ` Alexei Starovoitov
2020-10-12 1:26 ` Tianxianting [this message]
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