This is a note to let you know that I've just added the patch titled
bpf: hardcode BPF_PROG_PACK_SIZE to 2MB * num_possible_nodes()
to the 6.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
bpf-hardcode-bpf_prog_pack_size-to-2mb-num_possible_.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 31a9e6b342f63e360a2a91478e78520bf92d7eea
Author: Puranjay Mohan <puranjay12@xxxxxxxxx>
Date: Mon Mar 11 12:27:22 2024 +0000
bpf: hardcode BPF_PROG_PACK_SIZE to 2MB * num_possible_nodes()
[ Upstream commit d6170e4aaf86424c24ce06e355b4573daa891b17 ]
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 size for allocations done through
the prog pack allocator. On most architectures, PMD_SIZE will be equal
to 2MB in case of 4KB pages and will be greater than 2MB for bigger page
sizes.
Fixes: ea2babac63d4 ("bpf: Simplify bpf_prog_pack_[size|mask]")
Reported-by: "kernelci.org bot" <bot@xxxxxxxxxxxx>
Closes: https://lore.kernel.org/all/7e216c88-77ee-47b8-becc-a0f780868d3c@xxxxxxxxxxxxx/
Reported-by: kernel test robot <lkp@xxxxxxxxx>
Closes: https://lore.kernel.org/oe-kbuild-all/202403092219.dhgcuz2G-lkp@xxxxxxxxx/
Suggested-by: Song Liu <song@xxxxxxxxxx>
Signed-off-by: Puranjay Mohan <puranjay12@xxxxxxxxx>
Message-ID: <20240311122722.86232-1-puranjay12@xxxxxxxxx>
Signed-off-by: Alexei Starovoitov <ast@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index 5d1efe5200ba3..1333273a71ded 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -863,7 +863,12 @@ static LIST_HEAD(pack_list);
* CONFIG_MMU=n. Use PAGE_SIZE in these cases.
*/
#ifdef PMD_SIZE
-#define BPF_PROG_PACK_SIZE (PMD_SIZE * num_possible_nodes())
+/* PMD_SIZE is really big for some archs. It doesn't make sense to
+ * reserve too much memory in one allocation. Hardcode BPF_PROG_PACK_SIZE to
+ * 2MiB * num_possible_nodes(). On most architectures PMD_SIZE will be
+ * greater than or equal to 2MB.
+ */
+#define BPF_PROG_PACK_SIZE (SZ_2M * num_possible_nodes())
#else
#define BPF_PROG_PACK_SIZE PAGE_SIZE
#endif
