From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 7649C23D7DB for ; Wed, 31 Dec 2025 14:14:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767190484; cv=none; b=SnQKb3cURaREJ1KB+pRNgb7teUnIEnbJ9mVMSqmwHkCbHDkYEAml90rZoeHD9Q1NM38WFB6mQKUWBbTNsWWbyyjTInSIwzxiLZHOc/VLqQHlYekWWuiP6FqH3Zyb0BmZViww4gwWPypFzDsymf0A5MdIln0sRKrtEdVF/3YkNVI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767190484; c=relaxed/simple; bh=KdXTRQxgvOK76y13k27MzIaGCd6CHqTj8FkDxcFw4Ac=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=kJ1zVR2iBUCd+nepR8Qtq+ORJSIOl1vFf4nR1jdUpkTSFKH6Zt12SvTCcn9LlvZHOeSbP6Yj6GASJBdnU73WqFgHMLYaTyg19a4Pl6lPYehcpk3vhePywr+oH5ggTaoCg+VIxwJugo3rS9iOE3nSo3m8VvEXphxu59J2ZSOuiz8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=AHvMGKtE; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="AHvMGKtE" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9B662C113D0; Wed, 31 Dec 2025 14:14:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1767190483; bh=KdXTRQxgvOK76y13k27MzIaGCd6CHqTj8FkDxcFw4Ac=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=AHvMGKtEXJOBaGP7kztO2Pw5xybn2HTXYGjR1Ct3gxN0dUVK/Sjdl9EgCAmJwYdMC 8tRgO0KEcjljfgrUenhSWYmJBZJDMwYa52wfLIxPUaavlMcQjFETppqjqcxA3EsbaL aUPQvh/O52uqN7UGqPz/A/Krxi+sEL37I/OysPjD8dzKak+c+bJhbTWHpSGOftqik2 MpZp3YBN9SBUSzQKWZKDUlHpYmhTa8cDEHAcJU2WW1iGx+zwCS8lkmXCsIHkUsTlTD /s8ufScOq5HR/JlR9r8TUe/TPLCPKolP1XklzNHb6o5Dj8M+1aOL3UrRfW/Pe2LnoD KhE05FUzg854A== From: Puranjay Mohan To: bpf@vger.kernel.org Cc: Puranjay Mohan , Puranjay Mohan , Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann , Martin KaFai Lau , Eduard Zingerman , Kumar Kartikeya Dwivedi , kernel-team@meta.com Subject: [PATCH bpf-next v2 1/2] bpf: syscall: Introduce memcg enter/exit helpers Date: Wed, 31 Dec 2025 06:14:32 -0800 Message-ID: <20251231141434.3416822-2-puranjay@kernel.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20251231141434.3416822-1-puranjay@kernel.org> References: <20251231141434.3416822-1-puranjay@kernel.org> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Introduce bpf_map_memcg_enter() and bpf_map_memcg_exit() helpers to reduce code duplication in memcg context management. bpf_map_memcg_enter() gets the memcg from the map, sets it as active, and returns both the previous and the now active memcg. bpf_map_memcg_exit() restores the previous active memcg and releases the reference obtained during enter. Signed-off-by: Puranjay Mohan --- include/linux/bpf.h | 15 +++++++++++++ kernel/bpf/syscall.c | 50 +++++++++++++++++++++++--------------------- 2 files changed, 41 insertions(+), 24 deletions(-) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 4e7d72dfbcd4..24a32b1043d1 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -2608,6 +2608,10 @@ struct bpf_prog *bpf_prog_get_curr_or_next(u32 *id); int bpf_map_alloc_pages(const struct bpf_map *map, int nid, unsigned long nr_pages, struct page **page_array); #ifdef CONFIG_MEMCG +void bpf_map_memcg_enter(const struct bpf_map *map, struct mem_cgroup **old_memcg, + struct mem_cgroup **new_memcg); +void bpf_map_memcg_exit(struct mem_cgroup *old_memcg, + struct mem_cgroup *memcg); void *bpf_map_kmalloc_node(const struct bpf_map *map, size_t size, gfp_t flags, int node); void *bpf_map_kmalloc_nolock(const struct bpf_map *map, size_t size, gfp_t flags, @@ -2632,6 +2636,17 @@ void __percpu *bpf_map_alloc_percpu(const struct bpf_map *map, size_t size, kvcalloc(_n, _size, _flags) #define bpf_map_alloc_percpu(_map, _size, _align, _flags) \ __alloc_percpu_gfp(_size, _align, _flags) +static inline void bpf_map_memcg_enter(const struct bpf_map *map, struct mem_cgroup **old_memcg, + struct mem_cgroup **new_memcg) +{ + *new_memcg = NULL; + *old_memcg = NULL; +} + +static inline void bpf_map_memcg_exit(struct mem_cgroup *old_memcg, + struct mem_cgroup *memcg) +{ +} #endif static inline int diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index a4d38272d8bc..63849a06518b 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -505,17 +505,29 @@ static struct mem_cgroup *bpf_map_get_memcg(const struct bpf_map *map) return root_mem_cgroup; } +void bpf_map_memcg_enter(const struct bpf_map *map, struct mem_cgroup **old_memcg, + struct mem_cgroup **new_memcg) +{ + *new_memcg = bpf_map_get_memcg(map); + *old_memcg = set_active_memcg(*new_memcg); +} + +void bpf_map_memcg_exit(struct mem_cgroup *old_memcg, + struct mem_cgroup *new_memcg) +{ + set_active_memcg(old_memcg); + mem_cgroup_put(new_memcg); +} + void *bpf_map_kmalloc_node(const struct bpf_map *map, size_t size, gfp_t flags, int node) { struct mem_cgroup *memcg, *old_memcg; void *ptr; - memcg = bpf_map_get_memcg(map); - old_memcg = set_active_memcg(memcg); + bpf_map_memcg_enter(map, &old_memcg, &memcg); ptr = kmalloc_node(size, flags | __GFP_ACCOUNT, node); - set_active_memcg(old_memcg); - mem_cgroup_put(memcg); + bpf_map_memcg_exit(old_memcg, memcg); return ptr; } @@ -526,11 +538,9 @@ void *bpf_map_kmalloc_nolock(const struct bpf_map *map, size_t size, gfp_t flags struct mem_cgroup *memcg, *old_memcg; void *ptr; - memcg = bpf_map_get_memcg(map); - old_memcg = set_active_memcg(memcg); + bpf_map_memcg_enter(map, &old_memcg, &memcg); ptr = kmalloc_nolock(size, flags | __GFP_ACCOUNT, node); - set_active_memcg(old_memcg); - mem_cgroup_put(memcg); + bpf_map_memcg_exit(old_memcg, memcg); return ptr; } @@ -540,11 +550,9 @@ void *bpf_map_kzalloc(const struct bpf_map *map, size_t size, gfp_t flags) struct mem_cgroup *memcg, *old_memcg; void *ptr; - memcg = bpf_map_get_memcg(map); - old_memcg = set_active_memcg(memcg); + bpf_map_memcg_enter(map, &old_memcg, &memcg); ptr = kzalloc(size, flags | __GFP_ACCOUNT); - set_active_memcg(old_memcg); - mem_cgroup_put(memcg); + bpf_map_memcg_exit(old_memcg, memcg); return ptr; } @@ -555,11 +563,9 @@ void *bpf_map_kvcalloc(struct bpf_map *map, size_t n, size_t size, struct mem_cgroup *memcg, *old_memcg; void *ptr; - memcg = bpf_map_get_memcg(map); - old_memcg = set_active_memcg(memcg); + bpf_map_memcg_enter(map, &old_memcg, &memcg); ptr = kvcalloc(n, size, flags | __GFP_ACCOUNT); - set_active_memcg(old_memcg); - mem_cgroup_put(memcg); + bpf_map_memcg_exit(old_memcg, memcg); return ptr; } @@ -570,11 +576,9 @@ void __percpu *bpf_map_alloc_percpu(const struct bpf_map *map, size_t size, struct mem_cgroup *memcg, *old_memcg; void __percpu *ptr; - memcg = bpf_map_get_memcg(map); - old_memcg = set_active_memcg(memcg); + bpf_map_memcg_enter(map, &old_memcg, &memcg); ptr = __alloc_percpu_gfp(size, align, flags | __GFP_ACCOUNT); - set_active_memcg(old_memcg); - mem_cgroup_put(memcg); + bpf_map_memcg_exit(old_memcg, memcg); return ptr; } @@ -615,8 +619,7 @@ int bpf_map_alloc_pages(const struct bpf_map *map, int nid, #ifdef CONFIG_MEMCG struct mem_cgroup *memcg, *old_memcg; - memcg = bpf_map_get_memcg(map); - old_memcg = set_active_memcg(memcg); + bpf_map_memcg_enter(map, &old_memcg, &memcg); #endif for (i = 0; i < nr_pages; i++) { pg = __bpf_alloc_page(nid); @@ -632,8 +635,7 @@ int bpf_map_alloc_pages(const struct bpf_map *map, int nid, } #ifdef CONFIG_MEMCG - set_active_memcg(old_memcg); - mem_cgroup_put(memcg); + bpf_map_memcg_exit(old_memcg, memcg); #endif return ret; } -- 2.47.3