From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-189.mta1.migadu.com (out-189.mta1.migadu.com [95.215.58.189]) (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 74C8542D76F for ; Thu, 16 Jul 2026 14:29:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.189 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784212197; cv=none; b=NaVBfHndeN3+B7f81fs+OVw3Km4/3ROll993Pr1sG7LzECwDycSy625vZyfZ5Z/UTjEOPggjBzlxoQxBLqpmfbh4gsB3lmQzHlwCC+U/vk55A2PuwZIbK0/fGS9nm92p/ovaXO0oZcETrDENtfsYHBovgBBXFdC/idU27l5wkp0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784212197; c=relaxed/simple; bh=BxxAqyrCeGCBpKdz8J5FEt2zbeWNR4gQoleYdcIgo9k=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ZFjiJ6s0ovw5K7hW9C+pvzJR7nGJ7MUSP91utLsXryxA+x3jY9QqlPobTpY//kExlbbDx6cHThtqr+0k5YN0wQgToMh6AorP6Vx8XnB4gYg3zOycegRWKrE1KHLMzf+SNri8CqehV/J6bNuI6FY31Vs8zd+JAsoM4jAPEdsMOXU= 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=Pg5jj6Xz; arc=none smtp.client-ip=95.215.58.189 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="Pg5jj6Xz" 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=1784212193; 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=plL3HlABGOEsUMf+ise3vo4iORw/dt9juCk3f8Huqvk=; b=Pg5jj6XzDHjqPeNr+qBMawEEos7qWCrpY7VZHl3OojDj4zI24sPWgb5tJjjaNreWc6VUJn 4v3abesDzHRftzcK8VyFrnNAhUMAwwo13lCXaHzrQ7OQLrjpOH5F1UhP27Xv2PIAvuC5ds 0wORqEe482fuWWcTRAv3dAWvp0XQvrM= From: Jiayuan Chen To: bpf@vger.kernel.org, memxor@gmail.com Cc: Jiayuan Chen , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Eduard Zingerman , Martin KaFai Lau , Song Liu , Yonghong Song , Jiri Olsa , Emil Tsalapatis , Shuah Khan , Woojin Ji , Puranjay Mohan , Saket Kumar Bhaskar , Ihor Solodrai , linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org Subject: [PATCH bpf-next 3/3] selftests/bpf: Add tests for memory usage for arena Date: Thu, 16 Jul 2026 22:25:00 +0800 Message-ID: <20260716142746.8794-3-jiayuan.chen@linux.dev> In-Reply-To: <20260716142746.8794-1-jiayuan.chen@linux.dev> References: <20260716142746.8794-1-jiayuan.chen@linux.dev> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT Allocate and free arena pages, both from BPF and via user-space fault-in, and check that the map's memlock in fdinfo tracks the number of pages that are actually populated. Like the other arena tests it runs serially. test: ./test_progs -a arena_mem_usage #5 arena_mem_usage:OK Summary: 1/0 PASSED, 0 SKIPPED, 0 FAILED Signed-off-by: Jiayuan Chen --- .../bpf/prog_tests/arena_mem_usage.c | 122 ++++++++++++++++++ .../selftests/bpf/progs/arena_mem_usage.c | 39 ++++++ 2 files changed, 161 insertions(+) create mode 100644 tools/testing/selftests/bpf/prog_tests/arena_mem_usage.c create mode 100644 tools/testing/selftests/bpf/progs/arena_mem_usage.c diff --git a/tools/testing/selftests/bpf/prog_tests/arena_mem_usage.c b/tools/testing/selftests/bpf/prog_tests/arena_mem_usage.c new file mode 100644 index 000000000000..14c2d1a1d673 --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/arena_mem_usage.c @@ -0,0 +1,122 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include +#include +#ifndef PAGE_SIZE /* on some archs it comes in sys/user.h */ +#include +#define PAGE_SIZE getpagesize() +#endif + +#include "arena_mem_usage.skel.h" + +/* + * arena_map_mem_usage() is surfaced to user space through the map's + * /proc//fdinfo/ "memlock:" line (the same value bpftool map show + * prints). Read it directly so the test has no external dependency. + */ +static long map_memlock(int map_fd) +{ + char path[64], line[128]; + long memlock = -1; + FILE *f; + + snprintf(path, sizeof(path), "/proc/self/fdinfo/%d", map_fd); + f = fopen(path, "r"); + if (!ASSERT_OK_PTR(f, "open_fdinfo")) + return -1; + while (fgets(line, sizeof(line), f)) { + if (sscanf(line, "memlock:\t%ld", &memlock) == 1) + break; + } + fclose(f); + ASSERT_NEQ(memlock, -1, "parse_memlock"); + return memlock; +} + +static int run(struct bpf_program *prog, const char *name) +{ + LIBBPF_OPTS(bpf_test_run_opts, opts); + int err = bpf_prog_test_run_opts(bpf_program__fd(prog), &opts); + + if (!ASSERT_OK(err, name)) + return -1; + if (!ASSERT_OK(opts.retval, name)) + return -1; + return 0; +} + +void serial_test_arena_mem_usage(void) +{ + struct arena_mem_usage *skel; + const long ps = PAGE_SIZE; + char *base; + size_t sz; + int fd, i; + + skel = arena_mem_usage__open_and_load(); + if (!ASSERT_OK_PTR(skel, "open_load")) + return; + fd = bpf_map__fd(skel->maps.arena); + + /* Fresh arena: no data pages, and the scratch page is not counted. */ + ASSERT_EQ(map_memlock(fd), 0, "initial"); + + /* BPF-side allocation of 17 pages. */ + skel->bss->alloc_cnt = 17; + if (run(skel->progs.alloc, "alloc")) + goto out; + /* + * A NULL ptr means bpf_arena_alloc_pages() itself failed (e.g. the host + * is under memory pressure), not a miscount -- flag it distinctly so a + * red CI run is not mistaken for a counting bug. + */ + if (!ASSERT_OK_PTR(skel->bss->ptr, "arena_alloc_pages")) + goto out; + ASSERT_EQ(map_memlock(fd), 17 * ps, "after_alloc"); + + /* Free a single page (arena_free_pages page_cnt==1 path). */ + skel->bss->free_byte_off = 0; + skel->bss->free_cnt = 1; + if (run(skel->progs.free_pages, "free_one")) + goto out; + ASSERT_EQ(map_memlock(fd), 16 * ps, "after_free_one"); + + /* Free ten pages in one call (bulk path); only the freed pages count. */ + skel->bss->free_byte_off = 1 * ps; + skel->bss->free_cnt = 10; + if (run(skel->progs.free_pages, "free_bulk")) + goto out; + ASSERT_EQ(map_memlock(fd), 6 * ps, "after_free_bulk"); + + /* Free the remaining six -> arena empty again. */ + skel->bss->free_byte_off = 11 * ps; + skel->bss->free_cnt = 6; + if (run(skel->progs.free_pages, "free_rest")) + goto out; + ASSERT_EQ(map_memlock(fd), 0, "after_free_rest"); + + /* + * User-space fault-in: touching unallocated arena pages allocates them + * through arena_vm_fault(). libbpf mmap()s the arena at map_extra during + * load, so bpf_map__initial_value() hands back that base. + */ + base = bpf_map__initial_value(skel->maps.arena, &sz); + if (!ASSERT_OK_PTR(base, "arena_base")) + goto out; + for (i = 0; i < 8; i++) + base[i * ps] = 1; + ASSERT_EQ(map_memlock(fd), 8 * ps, "after_faultin"); + + /* + * Free the faulted-in pages from BPF. They are mapped into the user vma + * (elevated refcount), so this also exercises the zap path. + */ + skel->bss->ptr = base; + skel->bss->free_byte_off = 0; + skel->bss->free_cnt = 8; + if (run(skel->progs.free_pages, "free_faulted")) + goto out; + ASSERT_EQ(map_memlock(fd), 0, "after_free_faulted"); +out: + arena_mem_usage__destroy(skel); +} diff --git a/tools/testing/selftests/bpf/progs/arena_mem_usage.c b/tools/testing/selftests/bpf/progs/arena_mem_usage.c new file mode 100644 index 000000000000..50d9d6ac86f6 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/arena_mem_usage.c @@ -0,0 +1,39 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include +#include +#include "bpf_arena_common.h" + +struct { + __uint(type, BPF_MAP_TYPE_ARENA); + __uint(map_flags, BPF_F_MMAPABLE); + __uint(max_entries, 1000); /* number of pages */ +#ifdef __TARGET_ARCH_arm64 + __ulong(map_extra, 0x1ull << 32); /* start of mmap() region */ +#else + __ulong(map_extra, 0x1ull << 44); /* start of mmap() region */ +#endif +} arena SEC(".maps"); + +void __arena *ptr; +int alloc_cnt; /* in: pages to allocate */ +long free_byte_off; /* in: byte offset within ptr to start freeing */ +int free_cnt; /* in: pages to free */ + +SEC("syscall") +int alloc(void *ctx) +{ + ptr = bpf_arena_alloc_pages(&arena, NULL, alloc_cnt, NUMA_NO_NODE, 0); + return ptr ? 0 : 1; +} + +SEC("syscall") +int free_pages(void *ctx) +{ + if (!ptr) + return 1; + bpf_arena_free_pages(&arena, (char __arena *)ptr + free_byte_off, free_cnt); + return 0; +} + +char _license[] SEC("license") = "GPL"; -- 2.43.0