From 52dbd67dff5d050e99301100e2cac578eef9b2e9 Mon Sep 17 00:00:00 2001 From: "Jose E. Marchesi" Date: Thu, 8 Feb 2024 21:36:12 +0100 Subject: bpf: Abstract loop unrolling pragmas in BPF selftests [Changes from V1: - Avoid conflict by rebasing with latest master.] Some BPF tests use loop unrolling compiler pragmas that are clang specific and not supported by GCC. These pragmas, along with their GCC equivalences are: #pragma clang loop unroll_count(N) #pragma GCC unroll N #pragma clang loop unroll(full) #pragma GCC unroll 65534 #pragma clang loop unroll(disable) #pragma GCC unroll 1 #pragma unroll [aka #pragma clang loop unroll(enable)] There is no GCC equivalence to this pragma. It enables unrolling on loops that the compiler would not ordinarily unroll even with -O2|-funroll-loops, but it is not equivalent to full unrolling either. This patch adds a new header progs/bpf_compiler.h that defines the following macros, which correspond to each pair of compiler-specific pragmas above: __pragma_loop_unroll_count(N) __pragma_loop_unroll_full __pragma_loop_no_unroll __pragma_loop_unroll The selftests using loop unrolling pragmas are then changed to include the header and use these macros in place of the explicit pragmas. Tested in bpf-next master. No regressions. Signed-off-by: Jose E. Marchesi Signed-off-by: Andrii Nakryiko Acked-by: Yonghong Song Link: https://lore.kernel.org/bpf/20240208203612.29611-1-jose.marchesi@oracle.com --- tools/testing/selftests/bpf/progs/test_sysctl_prog.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'tools/testing/selftests/bpf/progs/test_sysctl_prog.c') diff --git a/tools/testing/selftests/bpf/progs/test_sysctl_prog.c b/tools/testing/selftests/bpf/progs/test_sysctl_prog.c index 5489823c83fc..efc3c61f7852 100644 --- a/tools/testing/selftests/bpf/progs/test_sysctl_prog.c +++ b/tools/testing/selftests/bpf/progs/test_sysctl_prog.c @@ -9,6 +9,8 @@ #include +#include "bpf_compiler.h" + /* Max supported length of a string with unsigned long in base 10 (pow2 - 1). */ #define MAX_ULONG_STR_LEN 0xF @@ -31,7 +33,7 @@ static __always_inline int is_tcp_mem(struct bpf_sysctl *ctx) if (ret < 0 || ret != sizeof(tcp_mem_name) - 1) return 0; -#pragma clang loop unroll(full) + __pragma_loop_unroll_full for (i = 0; i < sizeof(tcp_mem_name); ++i) if (name[i] != tcp_mem_name[i]) return 0; @@ -57,7 +59,7 @@ int sysctl_tcp_mem(struct bpf_sysctl *ctx) if (ret < 0 || ret >= MAX_VALUE_STR_LEN) return 0; -#pragma clang loop unroll(full) + __pragma_loop_unroll_full for (i = 0; i < ARRAY_SIZE(tcp_mem); ++i) { ret = bpf_strtoul(value + off, MAX_ULONG_STR_LEN, 0, tcp_mem + i); -- cgit v1.2.3