linux/kernel/bpf
Hou Tao af66bfd3c8 bpf: Optimize the free of inner map
When removing the inner map from the outer map, the inner map will be
freed after one RCU grace period and one RCU tasks trace grace
period, so it is certain that the bpf program, which may access the
inner map, has exited before the inner map is freed.

However there is no need to wait for one RCU tasks trace grace period if
the outer map is only accessed by non-sleepable program. So adding
sleepable_refcnt in bpf_map and increasing sleepable_refcnt when adding
the outer map into env->used_maps for sleepable program. Although the
max number of bpf program is INT_MAX - 1, the number of bpf programs
which are being loaded may be greater than INT_MAX, so using atomic64_t
instead of atomic_t for sleepable_refcnt. When removing the inner map
from the outer map, using sleepable_refcnt to decide whether or not a
RCU tasks trace grace period is needed before freeing the inner map.

Signed-off-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20231204140425.1480317-6-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-12-04 17:50:26 -08:00
..
preload bpf: make preloaded map iterators to display map elements count 2023-07-06 12:42:25 -07:00
arraymap.c bpf: Set need_defer as false when clearing fd array during map free 2023-12-04 17:50:26 -08:00
bloom_filter.c bpf: Centralize permissions checks for all BPF map types 2023-06-19 14:04:04 +02:00
bpf_cgrp_storage.c bpf: Teach verifier that certain helpers accept NULL pointer. 2023-04-04 16:57:16 -07:00
bpf_inode_storage.c Networking changes for 6.4. 2023-04-26 16:07:23 -07:00
bpf_iter.c bpf: Add __bpf_kfunc_{start,end}_defs macros 2023-11-01 22:33:53 -07:00
bpf_local_storage.c bpf: bpf_sk_storage: Fix the missing uncharge in sk_omem_alloc 2023-09-06 11:08:14 +02:00
bpf_lru_list.c bpf: Address KCSAN report on bpf_lru_list 2023-05-12 12:01:03 -07:00
bpf_lru_list.h bpf: lru: Remove unused declaration bpf_lru_promote() 2023-08-08 17:21:42 -07:00
bpf_lsm.c bpf: Fix the kernel crash caused by bpf_setsockopt(). 2023-01-26 23:26:40 -08:00
bpf_struct_ops.c bpf: Charge modmem for struct_ops trampoline 2023-09-14 15:30:45 -07:00
bpf_struct_ops_types.h bpf: Add dummy BPF STRUCT_OPS for test purpose 2021-11-01 14:10:00 -07:00
bpf_task_storage.c bpf: Teach verifier that certain helpers accept NULL pointer. 2023-04-04 16:57:16 -07:00
btf.c bpf: Move GRAPH_{ROOT,NODE}_MASK macros into btf_field_type enum 2023-11-09 19:07:51 -08:00
cgroup.c for-6.7/io_uring-sockopt-2023-10-30 2023-11-01 11:16:34 -10:00
cgroup_iter.c bpf: Let verifier consider {task,cgroup} is trusted in bpf_iter_reg 2023-11-07 15:24:25 -08:00
core.c bpf: Optimize the free of inner map 2023-12-04 17:50:26 -08:00
cpumap.c net, bpf: Add a warning if NAPI cb missed xdp_do_flush(). 2023-10-17 15:02:03 +02:00
cpumask.c bpf: Add __bpf_kfunc_{start,end}_defs macros 2023-11-01 22:33:53 -07:00
devmap.c net, bpf: Add a warning if NAPI cb missed xdp_do_flush(). 2023-10-17 15:02:03 +02:00
disasm.c bpf: change bpf_alu_sign_string and bpf_movsx_string to static 2023-08-04 16:15:50 -07:00
disasm.h
dispatcher.c bpf: Synchronize dispatcher update with bpf_dispatcher_xdp_func 2022-12-14 12:02:14 -08:00
hashtab.c bpf: Add map and need_defer parameters to .map_fd_put_ptr() 2023-12-04 17:50:26 -08:00
helpers.c bpf: Check rcu_read_lock_trace_held() before calling bpf map helpers 2023-12-04 17:50:26 -08:00
inode.c bpf: convert to new timestamp accessors 2023-10-18 14:08:30 +02:00
Kconfig bpf: Add fd-based tcx multi-prog infra with link support 2023-07-19 10:07:27 -07:00
link_iter.c bpf: Add bpf_link iterator 2022-05-10 11:20:45 -07:00
local_storage.c cgroup changes for v6.4-rc1 2023-04-29 10:05:22 -07:00
log.c bpf: simplify tnum output if a fully known constant 2023-12-02 11:36:51 -08:00
lpm_trie.c bpf, lpm: Fix check prefixlen before walking trie 2023-11-09 19:07:38 -08:00
Makefile bpf: Add fd-based tcx multi-prog infra with link support 2023-07-19 10:07:27 -07:00
map_in_map.c bpf: Optimize the free of inner map 2023-12-04 17:50:26 -08:00
map_in_map.h bpf: Add map and need_defer parameters to .map_fd_put_ptr() 2023-12-04 17:50:26 -08:00
map_iter.c bpf: Add __bpf_kfunc_{start,end}_defs macros 2023-11-01 22:33:53 -07:00
memalloc.c bpf: Add missed allocation hint for bpf_mem_cache_alloc_flags() 2023-11-26 18:00:26 -08:00
mmap_unlock_work.h bpf: Introduce helper bpf_find_vma 2021-11-07 11:54:51 -08:00
mprog.c bpf: Handle bpf_mprog_query with NULL entry 2023-10-06 17:11:20 -07:00
net_namespace.c net: Add includes masked by netdevice.h including uapi/bpf.h 2021-12-29 20:03:05 -08:00
offload.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2023-09-21 21:49:45 +02:00
percpu_freelist.c bpf: Initialize same number of free nodes for each pcpu_freelist 2022-11-11 12:05:14 -08:00
percpu_freelist.h
prog_iter.c
queue_stack_maps.c bpf: Avoid deadlock when using queue and stack maps from NMI 2023-09-11 19:04:49 -07:00
reuseport_array.c bpf: Centralize permissions checks for all BPF map types 2023-06-19 14:04:04 +02:00
ringbuf.c bpf: Fold smp_mb__before_atomic() into atomic_set_release() 2023-10-24 14:26:07 +02:00
stackmap.c bpf: Add crosstask check to __bpf_get_stack 2023-11-10 11:06:10 -08:00
syscall.c bpf: Optimize the free of inner map 2023-12-04 17:50:26 -08:00
sysfs_btf.c
task_iter.c bpf: bpf_iter_task_next: use next_task(kit->task) rather than next_task(kit->pos) 2023-11-19 11:43:44 -08:00
tcx.c bpf, tcx: Get rid of tcx_link_const 2023-10-23 15:01:53 -07:00
tnum.c bpf: simplify tnum output if a fully known constant 2023-12-02 11:36:51 -08:00
trampoline.c bpf, x64: Fix tailcall infinite loop 2023-09-12 13:06:12 -07:00
verifier.c bpf: Optimize the free of inner map 2023-12-04 17:50:26 -08:00