Alexei Starovoitov 15a07b3381 bpf: add lookup/update support for per-cpu hash and array maps ... The functions bpf_map_lookup_elem(map, key, value) and bpf_map_update_elem(map, key, value, flags) need to get/set values from all-cpus for per-cpu hash and array maps, so that user space can aggregate/update them as necessary. Example of single counter aggregation in user space: unsigned int nr_cpus = sysconf(_SC_NPROCESSORS_CONF); long values[nr_cpus]; long value = 0; bpf_lookup_elem(fd, key, values); for (i = 0; i < nr_cpus; i++) value += values[i]; The user space must provide round_up(value_size, 8) * nr_cpus array to get/set values, since kernel will use 'long' copy of per-cpu values to try to copy good counters atomically. It's a best-effort, since bpf programs and user space are racing to access the same memory. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>		2016-02-06 03:34:36 -05:00
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arraymap.c	bpf: add lookup/update support for per-cpu hash and array maps	2016-02-06 03:34:36 -05:00
core.c	bpf: move clearing of A/X into classic to eBPF migration prologue	2015-12-18 16:04:51 -05:00
hashtab.c	bpf: add lookup/update support for per-cpu hash and array maps	2016-02-06 03:34:36 -05:00
helpers.c	bpf: split state from prandom_u32() and consolidate {c, e}BPF prngs	2015-10-08 05:26:39 -07:00
inode.c	bpf, inode: allow for rename and link ops	2015-12-12 18:44:23 -05:00
Makefile	bpf: add support for persistent maps/progs	2015-11-02 22:48:39 -05:00
syscall.c	bpf: add lookup/update support for per-cpu hash and array maps	2016-02-06 03:34:36 -05:00
verifier.c	net: bpf: reject invalid shifts	2016-01-12 17:06:53 -05:00