fprobe: use rhashtable for fprobe_ip_table #9504
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For now, all the kernel functions who are hooked by the fprobe will be added to the hash table "fprobe_ip_table". The key of it is the function address, and the value of it is "struct fprobe_hlist_node". The budget of the hash table is FPROBE_IP_TABLE_SIZE, which is 256. And this means the overhead of the hash table lookup will grow linearly if the count of the functions in the fprobe more than 256. When we try to hook all the kernel functions, the overhead will be huge. Therefore, replace the hash table with rhltable to reduce the overhead. Signed-off-by: Menglong Dong <[email protected]>
We need to get all the kernel function that can be traced sometimes, so we move the get_syms() and get_addrs() in kprobe_multi_test.c to trace_helpers.c and rename it to bpf_get_ksyms() and bpf_get_addrs(). Signed-off-by: Menglong Dong <[email protected]>
Some functions is recursive for the kprobe_multi and impact the benchmark results. So just skip them. Signed-off-by: Menglong Dong <[email protected]>
For now, the benchmark for kprobe-multi is single, which means there is only 1 function is hooked during testing. Add the testing "kprobe-multi-all", which will hook all the kernel functions during the benchmark. And the "kretprobe-multi-all" is added too. Signed-off-by: Menglong Dong <[email protected]>
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Upstream branch: 3ec8560 |
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Pull request for series with
subject: fprobe: use rhashtable for fprobe_ip_table
version: 5
url: https://patchwork.kernel.org/project/netdevbpf/list/?series=992227