On Mon, Oct 16, 2017 at 12:19:28PM +0200, Jesper Dangaard Brouer wrote: > The 'cpumap' is primarily used as a backend map for XDP BPF helper > call bpf_redirect_map() and XDP_REDIRECT action, like 'devmap'. > > This patch implement the main part of the map. It is not connected to > the XDP redirect system yet, and no SKB allocation are done yet. > > The main concern in this patch is to ensure the datapath can run > without any locking. This adds complexity to the setup and tear-down > procedure, which assumptions are extra carefully documented in the > code comments. > > V2: > - make sure array isn't larger than NR_CPUS > - make sure CPUs added is a valid possible CPU > > V3: fix nitpicks from Jakub Kicinski <kubak...@wp.pl> > > V5: > - Restrict map allocation to root / CAP_SYS_ADMIN > - WARN_ON_ONCE if queue is not empty on tear-down > - Return -EPERM on memlock limit instead of -ENOMEM > - Error code in __cpu_map_entry_alloc() also handle ptr_ring_cleanup() > - Moved cpu_map_enqueue() to next patch > > V6: all notice by Daniel Borkmann > - Fix err return code in cpu_map_alloc() introduced in V5 > - Move cpu_possible() check after max_entries boundary check > - Forbid usage initially in check_map_func_compatibility() > > V7: > - Fix alloc error path spotted by Daniel Borkmann > - Did stress test adding+removing CPUs from the map concurrently > - Fixed refcnt issue on cpu_map_entry, kthread started too soon > - Make sure packets are flushed during tear-down, involved use of > rcu_barrier() and kthread_run only exit after queue is empty > - Fix alloc error path in __cpu_map_entry_alloc() for ptr_ring > > V8: > - Nitpicking comments and gramma by Edward Cree > - Fix missing semi-colon introduced in V7 due to rebasing > - Move struct bpf_cpu_map_entry members cpu+map_id to tracepoint patch > > Signed-off-by: Jesper Dangaard Brouer <bro...@redhat.com> > --- > include/linux/bpf_types.h | 1 > include/uapi/linux/bpf.h | 1 > kernel/bpf/Makefile | 1 > kernel/bpf/cpumap.c | 560 > ++++++++++++++++++++++++++++++++++++++++ > kernel/bpf/syscall.c | 8 + > kernel/bpf/verifier.c | 5 > tools/include/uapi/linux/bpf.h | 1 > 7 files changed, 576 insertions(+), 1 deletion(-) > create mode 100644 kernel/bpf/cpumap.c
Looks good to me I like the idea of running networking stack from kthread and hope adding GRO won't change the api. Acked-by: Alexei Starovoitov <a...@kernel.org>
