From 0f8e4bd8a1fc8c4185f1630061d0a1f2d197a475 Mon Sep 17 00:00:00 2001 From: Alexei Starovoitov Date: Thu, 13 Nov 2014 17:36:45 -0800 Subject: bpf: add hashtable type of eBPF maps add new map type BPF_MAP_TYPE_HASH and its implementation - maps are created/destroyed by userspace. Both userspace and eBPF programs can lookup/update/delete elements from the map - eBPF programs can be called in_irq(), so use spin_lock_irqsave() mechanism for concurrent updates - key/value are opaque range of bytes (aligned to 8 bytes) - user space provides 3 configuration attributes via BPF syscall: key_size, value_size, max_entries - map takes care of allocating/freeing key/value pairs - map_update_elem() must fail to insert new element when max_entries limit is reached to make sure that eBPF programs cannot exhaust memory - map_update_elem() replaces elements in an atomic way - optimized for speed of lookup() which can be called multiple times from eBPF program which itself is triggered by high volume of events . in the future JIT compiler may recognize lookup() call and optimize it further, since key_size is constant for life of eBPF program Signed-off-by: Alexei Starovoitov Signed-off-by: David S. Miller --- kernel/bpf/Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel/bpf/Makefile') diff --git a/kernel/bpf/Makefile b/kernel/bpf/Makefile index 0daf7f6ae7df..2c0ec7f9da78 100644 --- a/kernel/bpf/Makefile +++ b/kernel/bpf/Makefile @@ -1,5 +1,5 @@ obj-y := core.o -obj-$(CONFIG_BPF_SYSCALL) += syscall.o verifier.o +obj-$(CONFIG_BPF_SYSCALL) += syscall.o verifier.o hashtab.o ifdef CONFIG_TEST_BPF obj-$(CONFIG_BPF_SYSCALL) += test_stub.o endif -- cgit v1.2.3