2023-06-10 04:33:05

by David Vernet

[permalink] [raw]
Subject: [PATCH bpf-next 1/5] bpf: Add bpf_cpumask_first_and() kfunc

We currently provide bpf_cpumask_first(), bpf_cpumask_any(), and
bpf_cpumask_any_and() kfuncs. bpf_cpumask_any() and
bpf_cpumask_any_and() are confusing misnomers in that they actually just
call cpumask_first() and cpumask_first_and() respectively.

We'll replace them with bpf_cpumask_any_distribute() and
bpf_cpumask_any_distribute_and() kfuncs in a subsequent patch, so let's
ensure feature parity by adding a bpf_cpumask_first_and() kfunc to
account for bpf_cpumask_any_and() being removed.

Signed-off-by: David Vernet <[email protected]>
---
kernel/bpf/cpumask.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)

diff --git a/kernel/bpf/cpumask.c b/kernel/bpf/cpumask.c
index 7efdf5d770ca..9416c8ac8a04 100644
--- a/kernel/bpf/cpumask.c
+++ b/kernel/bpf/cpumask.c
@@ -131,6 +131,21 @@ __bpf_kfunc u32 bpf_cpumask_first_zero(const struct cpumask *cpumask)
return cpumask_first_zero(cpumask);
}

+/**
+ * bpf_cpumask_first_and() - Return the index of the first nonzero bit from the
+ * AND of two cpumasks.
+ * @src1: The first cpumask.
+ * @src2: The second cpumask.
+ *
+ * Find the index of the first nonzero bit of the AND of two cpumasks.
+ * struct bpf_cpumask pointers may be safely passed to @src1 and @src2.
+ */
+__bpf_kfunc u32 bpf_cpumask_first_and(const struct cpumask *src1,
+ const struct cpumask *src2)
+{
+ return cpumask_first_and(src1, src2);
+}
+
/**
* bpf_cpumask_set_cpu() - Set a bit for a CPU in a BPF cpumask.
* @cpu: The CPU to be set in the cpumask.
@@ -406,6 +421,7 @@ BTF_ID_FLAGS(func, bpf_cpumask_release, KF_RELEASE)
BTF_ID_FLAGS(func, bpf_cpumask_acquire, KF_ACQUIRE | KF_TRUSTED_ARGS)
BTF_ID_FLAGS(func, bpf_cpumask_first, KF_RCU)
BTF_ID_FLAGS(func, bpf_cpumask_first_zero, KF_RCU)
+BTF_ID_FLAGS(func, bpf_cpumask_first_and, KF_RCU)
BTF_ID_FLAGS(func, bpf_cpumask_set_cpu, KF_RCU)
BTF_ID_FLAGS(func, bpf_cpumask_clear_cpu, KF_RCU)
BTF_ID_FLAGS(func, bpf_cpumask_test_cpu, KF_RCU)
--
2.40.1



2023-06-10 06:16:19

by David Vernet

[permalink] [raw]
Subject: [PATCH bpf-next 2/5] selftests/bpf: Add test for new bpf_cpumask_first_and() kfunc

A prior patch added a new kfunc called bpf_cpumask_first_and() which
wraps cpumask_first_and(). This patch adds a selftest to validate its
behavior.

Signed-off-by: David Vernet <[email protected]>
---
.../selftests/bpf/prog_tests/cpumask.c | 1 +
.../selftests/bpf/progs/cpumask_common.h | 2 ++
.../selftests/bpf/progs/cpumask_success.c | 32 +++++++++++++++++++
3 files changed, 35 insertions(+)

diff --git a/tools/testing/selftests/bpf/prog_tests/cpumask.c b/tools/testing/selftests/bpf/prog_tests/cpumask.c
index d89191440fb1..756ea8b590b6 100644
--- a/tools/testing/selftests/bpf/prog_tests/cpumask.c
+++ b/tools/testing/selftests/bpf/prog_tests/cpumask.c
@@ -10,6 +10,7 @@ static const char * const cpumask_success_testcases[] = {
"test_set_clear_cpu",
"test_setall_clear_cpu",
"test_first_firstzero_cpu",
+ "test_firstand_nocpu",
"test_test_and_set_clear",
"test_and_or_xor",
"test_intersects_subset",
diff --git a/tools/testing/selftests/bpf/progs/cpumask_common.h b/tools/testing/selftests/bpf/progs/cpumask_common.h
index 0c5b785a93e4..b3493d5d263e 100644
--- a/tools/testing/selftests/bpf/progs/cpumask_common.h
+++ b/tools/testing/selftests/bpf/progs/cpumask_common.h
@@ -28,6 +28,8 @@ void bpf_cpumask_release(struct bpf_cpumask *cpumask) __ksym;
struct bpf_cpumask *bpf_cpumask_acquire(struct bpf_cpumask *cpumask) __ksym;
u32 bpf_cpumask_first(const struct cpumask *cpumask) __ksym;
u32 bpf_cpumask_first_zero(const struct cpumask *cpumask) __ksym;
+u32 bpf_cpumask_first_and(const struct cpumask *src1,
+ const struct cpumask *src2) __ksym;
void bpf_cpumask_set_cpu(u32 cpu, struct bpf_cpumask *cpumask) __ksym;
void bpf_cpumask_clear_cpu(u32 cpu, struct bpf_cpumask *cpumask) __ksym;
bool bpf_cpumask_test_cpu(u32 cpu, const struct cpumask *cpumask) __ksym;
diff --git a/tools/testing/selftests/bpf/progs/cpumask_success.c b/tools/testing/selftests/bpf/progs/cpumask_success.c
index 602a88b03dbc..fbaf510f4ab5 100644
--- a/tools/testing/selftests/bpf/progs/cpumask_success.c
+++ b/tools/testing/selftests/bpf/progs/cpumask_success.c
@@ -175,6 +175,38 @@ int BPF_PROG(test_first_firstzero_cpu, struct task_struct *task, u64 clone_flags
return 0;
}

+SEC("tp_btf/task_newtask")
+int BPF_PROG(test_firstand_nocpu, struct task_struct *task, u64 clone_flags)
+{
+ struct bpf_cpumask *mask1, *mask2;
+ u32 first;
+
+ if (!is_test_task())
+ return 0;
+
+ mask1 = create_cpumask();
+ if (!mask1)
+ return 0;
+
+ mask2 = create_cpumask();
+ if (!mask2)
+ goto release_exit;
+
+ bpf_cpumask_set_cpu(0, mask1);
+ bpf_cpumask_set_cpu(1, mask2);
+
+ first = bpf_cpumask_first_and(cast(mask1), cast(mask2));
+ if (first <= 1)
+ err = 3;
+
+release_exit:
+ if (mask1)
+ bpf_cpumask_release(mask1);
+ if (mask2)
+ bpf_cpumask_release(mask2);
+ return 0;
+}
+
SEC("tp_btf/task_newtask")
int BPF_PROG(test_test_and_set_clear, struct task_struct *task, u64 clone_flags)
{
--
2.40.1


2023-06-12 15:52:34

by Yonghong Song

[permalink] [raw]
Subject: Re: [PATCH bpf-next 1/5] bpf: Add bpf_cpumask_first_and() kfunc



On 6/9/23 8:50 PM, David Vernet wrote:
> We currently provide bpf_cpumask_first(), bpf_cpumask_any(), and
> bpf_cpumask_any_and() kfuncs. bpf_cpumask_any() and
> bpf_cpumask_any_and() are confusing misnomers in that they actually just
> call cpumask_first() and cpumask_first_and() respectively.
>
> We'll replace them with bpf_cpumask_any_distribute() and
> bpf_cpumask_any_distribute_and() kfuncs in a subsequent patch, so let's
> ensure feature parity by adding a bpf_cpumask_first_and() kfunc to
> account for bpf_cpumask_any_and() being removed.
>
> Signed-off-by: David Vernet <[email protected]>

Acked-by: Yonghong Song <[email protected]>

2023-06-12 15:55:52

by Yonghong Song

[permalink] [raw]
Subject: Re: [PATCH bpf-next 2/5] selftests/bpf: Add test for new bpf_cpumask_first_and() kfunc



On 6/9/23 8:50 PM, David Vernet wrote:
> A prior patch added a new kfunc called bpf_cpumask_first_and() which
> wraps cpumask_first_and(). This patch adds a selftest to validate its
> behavior.
>
> Signed-off-by: David Vernet <[email protected]>

Acked-by: Yonghong Song <[email protected]>

2023-06-12 22:41:51

by patchwork-bot+netdevbpf

[permalink] [raw]
Subject: Re: [PATCH bpf-next 1/5] bpf: Add bpf_cpumask_first_and() kfunc

Hello:

This series was applied to bpf/bpf-next.git (master)
by Alexei Starovoitov <[email protected]>:

On Fri, 9 Jun 2023 22:50:49 -0500 you wrote:
> We currently provide bpf_cpumask_first(), bpf_cpumask_any(), and
> bpf_cpumask_any_and() kfuncs. bpf_cpumask_any() and
> bpf_cpumask_any_and() are confusing misnomers in that they actually just
> call cpumask_first() and cpumask_first_and() respectively.
>
> We'll replace them with bpf_cpumask_any_distribute() and
> bpf_cpumask_any_distribute_and() kfuncs in a subsequent patch, so let's
> ensure feature parity by adding a bpf_cpumask_first_and() kfunc to
> account for bpf_cpumask_any_and() being removed.
>
> [...]

Here is the summary with links:
- [bpf-next,1/5] bpf: Add bpf_cpumask_first_and() kfunc
https://git.kernel.org/bpf/bpf-next/c/5ba3a7a851e3
- [bpf-next,2/5] selftests/bpf: Add test for new bpf_cpumask_first_and() kfunc
https://git.kernel.org/bpf/bpf-next/c/58476d8a24bd
- [bpf-next,3/5] bpf: Replace bpf_cpumask_any* with bpf_cpumask_any_distribute*
https://git.kernel.org/bpf/bpf-next/c/f983be917332
- [bpf-next,4/5] selftests/bpf: Update bpf_cpumask_any* tests to use bpf_cpumask_any_distribute*
https://git.kernel.org/bpf/bpf-next/c/5a73efc7d1b4
- [bpf-next,5/5] bpf/docs: Update documentation for new cpumask kfuncs
https://git.kernel.org/bpf/bpf-next/c/25085b4e9251

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