Re: [PATCH v2 1/3] bpf: allow zero-initializing hash map seed

On Thu, Oct 25, 2018 at 8:12 AM Lorenz Bauer [off-list ref] wrote:

On Tue, 9 Oct 2018 at 01:08, Song Liu [off-list ref] wrote:

quoted

quoted

--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h

@@ -253,6 +253,8 @@ enum bpf_attach_type {
 #define BPF_F_NO_COMMON_LRU    (1U << 1)
 /* Specify numa node during map creation */
 #define BPF_F_NUMA_NODE                (1U << 2)
+/* Zero-initialize hash function seed. This should only be used for testing. */
+#define BPF_F_ZERO_SEED                (1U << 6)

Please add this line after
#define BPF_F_STACK_BUILD_ID    (1U << 5)

I wanted to keep the flags for BPF_MAP_CREATE grouped together.
Maybe the correct value is (1U << 3)? It seemed like the other flags
were allocated to avoid
overlap between different BPF commands, however, so I tried to follow suit.

I think it should be (1U << 6). We probably should move BPF_F_QUERY_EFFECTIVE
to after BPF_F_STACK_BUILD_ID (and BPF_F_ZERO_SEED).

Also, please rebase against the latest bpf-next tree and resubmit the set.

Thanks,
Song