From mboxrd@z Thu Jan 1 00:00:00 1970 From: Yafang Shao Subject: [PATCH bpf-next v2 07/12] bpf: Introduce new helpers bpf_ringbuf_pages_{alloc,free} Date: Thu, 18 Aug 2022 14:31:13 +0000 Message-ID: <20220818143118.17733-8-laoar.shao@gmail.com> References: <20220818143118.17733-1-laoar.shao@gmail.com> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc; bh=wfVdiCm3ki6hY+6umh5GbzZ8nNKi0kDY1+Bd1ej/jM8=; b=RUKuxfm9E43E5qFQxMfS7R7LCmH7AoY/Gxkx5z0NnN217RoW+idxLKZwqN214SOPzH R7piyA5YeKysCY6mM/eUv7rthB/rLsOzSkIiO6t4LEipXfMIXU3WwDO0ARd+SR3DQWU1 tkAyiSTiSkiobEoeVQCt/ZI9GvL1pe3bJtnh8JJxazxASGrh8rnB1apZ+QqSExE7b2kC qD5Wc/SjTr44YPyHd3iQ7qvxVOILbekjFOJ7t7XHJTssYPcUuTdvujBMfI6eyq6W+J+q KvIEc61DmQwriVen4GenWzpC5f0TiuwN6owAG2711o9IGRTeXtqEAn03bgqrgWggFrhR pVPw== In-Reply-To: <20220818143118.17733-1-laoar.shao-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> List-ID: Content-Type: text/plain; charset="us-ascii" To: ast-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, daniel-FeC+5ew28dpmcu3hnIyYJQ@public.gmane.org, andrii-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, kafai-b10kYP2dOMg@public.gmane.org, songliubraving-b10kYP2dOMg@public.gmane.org, yhs-b10kYP2dOMg@public.gmane.org, john.fastabend-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, kpsingh-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, sdf-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org, haoluo-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org, jolsa-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, hannes-druUgvl0LCNAfugRpC6u6w@public.gmane.org, mhocko-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, roman.gushchin-fxUVXftIFDnyG1zEObXtfA@public.gmane.org, shakeelb-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org, songmuchun-EC8Uxl6Npydl57MIdRCFDg@public.gmane.org, akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org, tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, lizefan.x-EC8Uxl6Npydl57MIdRCFDg@public.gmane.org Cc: cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, netdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, bpf-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, Yafang Shao , Andrii Nakryiko Allocate pages related memory into the new helper bpf_ringbuf_pages_alloc(), then it can be handled as a single unit. Suggested-by: Andrii Nakryiko Signed-off-by: Yafang Shao --- kernel/bpf/ringbuf.c | 80 ++++++++++++++++++++++++++++++++++++---------------- 1 file changed, 56 insertions(+), 24 deletions(-) diff --git a/kernel/bpf/ringbuf.c b/kernel/bpf/ringbuf.c index 5eb7820..1e7284c 100644 --- a/kernel/bpf/ringbuf.c +++ b/kernel/bpf/ringbuf.c @@ -59,6 +59,57 @@ struct bpf_ringbuf_hdr { u32 pg_off; }; +static void bpf_ringbuf_pages_free(struct page **pages, int nr_pages) +{ + int i; + + for (i = 0; i < nr_pages; i++) + __free_page(pages[i]); + bpf_map_area_free(pages, NULL); +} + +static struct page **bpf_ringbuf_pages_alloc(struct bpf_map *map, + int nr_meta_pages, + int nr_data_pages, + int numa_node, + const gfp_t flags) +{ + int nr_pages = nr_meta_pages + nr_data_pages; + struct mem_cgroup *memcg, *old_memcg; + struct page **pages, *page; + int array_size; + int i; + + memcg = bpf_map_get_memcg(map); + old_memcg = set_active_memcg(memcg); + array_size = (nr_meta_pages + 2 * nr_data_pages) * sizeof(*pages); + pages = bpf_map_area_alloc(array_size, numa_node, NULL); + if (!pages) + goto err; + + for (i = 0; i < nr_pages; i++) { + page = alloc_pages_node(numa_node, flags, 0); + if (!page) { + nr_pages = i; + goto err_free_pages; + } + pages[i] = page; + if (i >= nr_meta_pages) + pages[nr_data_pages + i] = page; + } + set_active_memcg(old_memcg); + bpf_map_put_memcg(memcg); + + return pages; + +err_free_pages: + bpf_ringbuf_pages_free(pages, nr_pages); +err: + set_active_memcg(old_memcg); + bpf_map_put_memcg(memcg); + return NULL; +} + static struct bpf_ringbuf *bpf_ringbuf_area_alloc(size_t data_sz, int numa_node, struct bpf_map *map) { @@ -67,10 +118,8 @@ static struct bpf_ringbuf *bpf_ringbuf_area_alloc(size_t data_sz, int numa_node, int nr_meta_pages = RINGBUF_PGOFF + RINGBUF_POS_PAGES; int nr_data_pages = data_sz >> PAGE_SHIFT; int nr_pages = nr_meta_pages + nr_data_pages; - struct page **pages, *page; struct bpf_ringbuf *rb; - size_t array_size; - int i; + struct page **pages; /* Each data page is mapped twice to allow "virtual" * continuous read of samples wrapping around the end of ring @@ -89,22 +138,11 @@ static struct bpf_ringbuf *bpf_ringbuf_area_alloc(size_t data_sz, int numa_node, * when mmap()'ed in user-space, simplifying both kernel and * user-space implementations significantly. */ - array_size = (nr_meta_pages + 2 * nr_data_pages) * sizeof(*pages); - pages = bpf_map_area_alloc(array_size, numa_node, map); + pages = bpf_ringbuf_pages_alloc(map, nr_meta_pages, nr_data_pages, + numa_node, flags); if (!pages) return NULL; - for (i = 0; i < nr_pages; i++) { - page = alloc_pages_node(numa_node, flags, 0); - if (!page) { - nr_pages = i; - goto err_free_pages; - } - pages[i] = page; - if (i >= nr_meta_pages) - pages[nr_data_pages + i] = page; - } - rb = vmap(pages, nr_meta_pages + 2 * nr_data_pages, VM_MAP | VM_USERMAP, PAGE_KERNEL); if (rb) { @@ -114,10 +152,6 @@ static struct bpf_ringbuf *bpf_ringbuf_area_alloc(size_t data_sz, int numa_node, return rb; } -err_free_pages: - for (i = 0; i < nr_pages; i++) - __free_page(pages[i]); - bpf_map_area_free(pages, NULL); return NULL; } @@ -188,12 +222,10 @@ static void bpf_ringbuf_free(struct bpf_ringbuf *rb) * to unmap rb itself with vunmap() below */ struct page **pages = rb->pages; - int i, nr_pages = rb->nr_pages; + int nr_pages = rb->nr_pages; vunmap(rb); - for (i = 0; i < nr_pages; i++) - __free_page(pages[i]); - bpf_map_area_free(pages, NULL); + bpf_ringbuf_pages_free(pages, nr_pages); } static void ringbuf_map_free(struct bpf_map *map) -- 1.8.3.1