From nobody Mon Dec 1 23:11:14 2025 Received: from out-178.mta0.migadu.com (out-178.mta0.migadu.com [91.218.175.178]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C99093081DF for ; Wed, 26 Nov 2025 14:51:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.178 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764168710; cv=none; b=cLsFdeepQfePsbVr9dRzMoaDy608/EbaTkBrxcAHxq5znGcq1rd6uIaMs5PRPQMWDkpm/OAyc1WSD1YognsuoaIT78W0fjG3fagr4max1P/hpmE6VUavkAtbJyY0/Ceh00PGgWEPYx1MvkI4ifLsqRvfGryeJNQrT+rCDe8Vu30= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764168710; c=relaxed/simple; bh=vE/JPMmNA+Dn2lRE547H5bvN6VnYzpVVr1Dc/xgSluc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=cJs+Ske1bYIYswQRlpqxWeOtb4s5skeN4uMP0tLfZoU5DEcDrstDHL7k9BrZtkkzO/EWtEoiBs02SvQvoAk7IhP9M0TxuV7xhjaViws1TpE2P/rXfDDC5iehF/AJ+9k4BbteTQVTwMOXPr6S+8OAWP977KgyGSDZ4w/673ZldRQ= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=U70W6NrU; arc=none smtp.client-ip=91.218.175.178 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="U70W6NrU" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1764168706; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=BizZbmxMylmDygcgp8y5D9NypN6p1cqZpSSMPgibyaE=; b=U70W6NrULrKFMH/7K2KoBcnZFFWgfNzxdobhqHPd1Dg1QKnj/ws38pJ9iS0/hN1ujE2kDT mOevFF3ZCDQE7828jw9NWECp7LYYM9pBi7kdACZSKVk4TKewnf9d4OtaaHyECgm4jteJEO Of3X7yUpZmHNRwJxhzHheIxvq2ceX4Y= From: Leon Hwang To: bpf@vger.kernel.org Cc: ast@kernel.org, andrii@kernel.org, daniel@iogearbox.net, jolsa@kernel.org, yonghong.song@linux.dev, song@kernel.org, eddyz87@gmail.com, dxu@dxuuu.xyz, deso@posteo.net, martin.lau@linux.dev, john.fastabend@gmail.com, kpsingh@kernel.org, sdf@fomichev.me, haoluo@google.com, shuah@kernel.org, kerneljasonxing@gmail.com, chen.dylane@linux.dev, willemb@google.com, paul.chaignon@gmail.com, a.s.protopopov@gmail.com, memxor@gmail.com, yatsenko@meta.com, tklauser@distanz.ch, leon.hwang@linux.dev, kernel-patches-bot@fb.com, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org Subject: [PATCH bpf-next v12 2/7] bpf: Add BPF_F_CPU and BPF_F_ALL_CPUS flags support for percpu_array maps Date: Wed, 26 Nov 2025 22:50:34 +0800 Message-ID: <20251126145039.15715-3-leon.hwang@linux.dev> In-Reply-To: <20251126145039.15715-1-leon.hwang@linux.dev> References: <20251126145039.15715-1-leon.hwang@linux.dev> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Migadu-Flow: FLOW_OUT Content-Type: text/plain; charset="utf-8" Introduce support for the BPF_F_ALL_CPUS flag in percpu_array maps to allow updating values for all CPUs with a single value for both update_elem and update_batch APIs. Introduce support for the BPF_F_CPU flag in percpu_array maps to allow: * update value for specified CPU for both update_elem and update_batch APIs. * lookup value for specified CPU for both lookup_elem and lookup_batch APIs. The BPF_F_CPU flag is passed via: * map_flags of lookup_elem and update_elem APIs along with embedded cpu info. * elem_flags of lookup_batch and update_batch APIs along with embedded cpu info. Signed-off-by: Leon Hwang --- include/linux/bpf.h | 9 +++++++-- kernel/bpf/arraymap.c | 29 +++++++++++++++++++++++------ kernel/bpf/syscall.c | 2 +- 3 files changed, 31 insertions(+), 9 deletions(-) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index d84af3719b59..01a99e3a3e51 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -2762,7 +2762,7 @@ int map_set_for_each_callback_args(struct bpf_verifie= r_env *env, struct bpf_func_state *callee); =20 int bpf_percpu_hash_copy(struct bpf_map *map, void *key, void *value); -int bpf_percpu_array_copy(struct bpf_map *map, void *key, void *value); +int bpf_percpu_array_copy(struct bpf_map *map, void *key, void *value, u64= flags); int bpf_percpu_hash_update(struct bpf_map *map, void *key, void *value, u64 flags); int bpf_percpu_array_update(struct bpf_map *map, void *key, void *value, @@ -3831,7 +3831,12 @@ bpf_prog_update_insn_ptrs(struct bpf_prog *prog, u32= *offsets, void *image) =20 static inline bool bpf_map_supports_cpu_flags(enum bpf_map_type map_type) { - return false; + switch (map_type) { + case BPF_MAP_TYPE_PERCPU_ARRAY: + return true; + default: + return false; + } } =20 static inline int bpf_map_check_op_flags(struct bpf_map *map, u64 flags, u= 64 allowed_flags) diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c index 1eeb31c5b317..67e9e811de3a 100644 --- a/kernel/bpf/arraymap.c +++ b/kernel/bpf/arraymap.c @@ -307,7 +307,7 @@ static void *percpu_array_map_lookup_percpu_elem(struct= bpf_map *map, void *key, return per_cpu_ptr(array->pptrs[index & array->index_mask], cpu); } =20 -int bpf_percpu_array_copy(struct bpf_map *map, void *key, void *value) +int bpf_percpu_array_copy(struct bpf_map *map, void *key, void *value, u64= map_flags) { struct bpf_array *array =3D container_of(map, struct bpf_array, map); u32 index =3D *(u32 *)key; @@ -325,11 +325,18 @@ int bpf_percpu_array_copy(struct bpf_map *map, void *= key, void *value) size =3D array->elem_size; rcu_read_lock(); pptr =3D array->pptrs[index & array->index_mask]; + if (map_flags & BPF_F_CPU) { + cpu =3D map_flags >> 32; + copy_map_value(map, value, per_cpu_ptr(pptr, cpu)); + check_and_init_map_value(map, value); + goto unlock; + } for_each_possible_cpu(cpu) { copy_map_value_long(map, value + off, per_cpu_ptr(pptr, cpu)); check_and_init_map_value(map, value + off); off +=3D size; } +unlock: rcu_read_unlock(); return 0; } @@ -398,10 +405,11 @@ int bpf_percpu_array_update(struct bpf_map *map, void= *key, void *value, struct bpf_array *array =3D container_of(map, struct bpf_array, map); u32 index =3D *(u32 *)key; void __percpu *pptr; - int cpu, off =3D 0; + void *ptr, *val; u32 size; + int cpu; =20 - if (unlikely(map_flags > BPF_EXIST)) + if (unlikely((map_flags & BPF_F_LOCK) || (u32)map_flags > BPF_F_ALL_CPUS)) /* unknown flags */ return -EINVAL; =20 @@ -422,11 +430,20 @@ int bpf_percpu_array_update(struct bpf_map *map, void= *key, void *value, size =3D array->elem_size; rcu_read_lock(); pptr =3D array->pptrs[index & array->index_mask]; + if (map_flags & BPF_F_CPU) { + cpu =3D map_flags >> 32; + ptr =3D per_cpu_ptr(pptr, cpu); + copy_map_value(map, ptr, value); + bpf_obj_free_fields(array->map.record, ptr); + goto unlock; + } for_each_possible_cpu(cpu) { - copy_map_value_long(map, per_cpu_ptr(pptr, cpu), value + off); - bpf_obj_free_fields(array->map.record, per_cpu_ptr(pptr, cpu)); - off +=3D size; + ptr =3D per_cpu_ptr(pptr, cpu); + val =3D (map_flags & BPF_F_ALL_CPUS) ? value : value + size * cpu; + copy_map_value(map, ptr, val); + bpf_obj_free_fields(array->map.record, ptr); } +unlock: rcu_read_unlock(); return 0; } diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 7a1d0ce8fa57..6aa98257fa3f 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -318,7 +318,7 @@ static int bpf_map_copy_value(struct bpf_map *map, void= *key, void *value, map->map_type =3D=3D BPF_MAP_TYPE_LRU_PERCPU_HASH) { err =3D bpf_percpu_hash_copy(map, key, value); } else if (map->map_type =3D=3D BPF_MAP_TYPE_PERCPU_ARRAY) { - err =3D bpf_percpu_array_copy(map, key, value); + err =3D bpf_percpu_array_copy(map, key, value, flags); } else if (map->map_type =3D=3D BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE) { err =3D bpf_percpu_cgroup_storage_copy(map, key, value); } else if (map->map_type =3D=3D BPF_MAP_TYPE_STACK_TRACE) { --=20 2.51.2