From 09718f4ecdb13fd6a3fcffc8933d02300cc106c7 Mon Sep 17 00:00:00 2001 From: Song Liu Date: Wed, 30 Sep 2020 15:49:26 -0700 Subject: [PATCH] bpf: Introduce BPF_F_PRESERVE_ELEMS for perf event array Currently, perf event in perf event array is removed from the array when the map fd used to add the event is closed. This behavior makes it difficult to the share perf events with perf event array. Introduce perf event map that keeps the perf event open with a new flag BPF_F_PRESERVE_ELEMS. With this flag set, perf events in the array are not removed when the original map fd is closed. Instead, the perf event will stay in the map until 1) it is explicitly removed from the array; or 2) the array is freed. Signed-off-by: Song Liu Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20200930224927.1936644-2-songliubraving@fb.com --- include/uapi/linux/bpf.h | 3 +++ 1 file changed, 3 insertions(+) diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 1f17c67..4f556cf 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -414,6 +414,9 @@ enum { /* Enable memory-mapping BPF map */ BPF_F_MMAPABLE = (1U << 10), + +/* Share perf_event among processes */ + BPF_F_PRESERVE_ELEMS = (1U << 11), }; /* Flags for BPF_PROG_QUERY. */