bpf.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Puranjay Mohan <puranjay12@gmail.com>
To: Alexei Starovoitov <ast@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>,
	John Fastabend <john.fastabend@gmail.com>,
	Andrii Nakryiko <andrii@kernel.org>,
	Martin KaFai Lau <martin.lau@linux.dev>,
	Eduard Zingerman <eddyz87@gmail.com>, Song Liu <song@kernel.org>,
	Yonghong Song <yonghong.song@linux.dev>,
	KP Singh <kpsingh@kernel.org>,
	Stanislav Fomichev <sdf@google.com>, Hao Luo <haoluo@google.com>,
	Jiri Olsa <jolsa@kernel.org>,
	bpf@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: puranjay12@gmail.com
Subject: [PATCH bpf-next] bpf: cap BPF_PROG_PACK_SIZE to 2MB * num_possible_nodes()
Date: Fri,  8 Mar 2024 12:07:12 +0000	[thread overview]
Message-ID: <20240308120712.88122-1-puranjay12@gmail.com> (raw)

On some architectures like ARM64, PMD_SIZE can be really large in some
configurations. Like with CONFIG_ARM64_64K_PAGES=y the PMD_SIZE is
512MB.

Use 2MB * num_possible_nodes() as the upper limit for allocations done
through the prog pack allocator.

Fixes: ea2babac63d4 ("bpf: Simplify bpf_prog_pack_[size|mask]")
Reported-by: "kernelci.org bot" <bot@kernelci.org>
Closes: https://lore.kernel.org/all/7e216c88-77ee-47b8-becc-a0f780868d3c@sirena.org.uk/
Suggested-by: Song Liu <song@kernel.org>
Signed-off-by: Puranjay Mohan <puranjay12@gmail.com>
---
 kernel/bpf/core.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index 134b7979f537..83a3b6964e54 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -893,8 +893,17 @@ static LIST_HEAD(pack_list);
  * CONFIG_MMU=n. Use PAGE_SIZE in these cases.
  */
 #ifdef PMD_SIZE
+/*
+ * PMD_SIZE is really big for some archs. It doesn't make sense to
+ * reserve too much memory in one allocation. Cap BPF_PROG_PACK_SIZE to
+ * 2MiB * num_possible_nodes().
+ */
+#if PMD_SIZE <= (1 << 21)
 #define BPF_PROG_PACK_SIZE (PMD_SIZE * num_possible_nodes())
 #else
+#define BPF_PROG_PACK_SIZE ((1 << 21) * num_possible_nodes())
+#endif
+#else
 #define BPF_PROG_PACK_SIZE PAGE_SIZE
 #endif
 
-- 
2.40.1


             reply	other threads:[~2024-03-08 12:07 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-03-08 12:07 Puranjay Mohan [this message]
2024-03-08 16:55 ` [PATCH bpf-next] bpf: cap BPF_PROG_PACK_SIZE to 2MB * num_possible_nodes() Song Liu
2024-03-08 23:08   ` Alexei Starovoitov

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20240308120712.88122-1-puranjay12@gmail.com \
    --to=puranjay12@gmail.com \
    --cc=andrii@kernel.org \
    --cc=ast@kernel.org \
    --cc=bpf@vger.kernel.org \
    --cc=daniel@iogearbox.net \
    --cc=eddyz87@gmail.com \
    --cc=haoluo@google.com \
    --cc=john.fastabend@gmail.com \
    --cc=jolsa@kernel.org \
    --cc=kpsingh@kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=martin.lau@linux.dev \
    --cc=sdf@google.com \
    --cc=song@kernel.org \
    --cc=yonghong.song@linux.dev \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).