af-alg stressor triggers modprobe throttling
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
Stress-ng |
Fix Released
|
Medium
|
Colin Ian King | ||
linux (Ubuntu) |
Incomplete
|
Low
|
Unassigned |
Bug Description
Due to the combination of high core counts and perhaps a lack of available hash/crypto hardware acceleration drivers, arm64 server platforms generate a lot of noisy modprobe throttling messages when running the af-alg stressor. This appears to be partially mitigated in master by disabling hashes/ciphers once they are found to be not present. But, w/ 96 cores/hogs, we presumably still hit the kernel with 96 * (nr_hashes + nr_ciphers) before that mitigation takes effect, and that is sufficient to cause the kernel to emit throttling messages.
$ sudo dmesg -c > /dev/null ; ./stress-ng --af-alg 0 --af-alg-
stress-ng: info: [76141] defaulting to a 86400 second (1 day, 0.00 secs) run per stressor
stress-ng: info: [76141] dispatching hogs: 96 af-alg
stress-ng: info: [76141] successful run completed in 0.40s
[ 5808.489046] __request_module: 25 callbacks suppressed
[ 5808.489050] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-ghash, throttling...
[ 5808.489503] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-ghash, throttling...
[ 5808.489724] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-ghash, throttling...
[ 5808.489731] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-ghash, throttling...
[ 5808.490092] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-xor-all, throttling...
[ 5808.490235] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-ghash-all, throttling...
[ 5808.490308] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-ghash, throttling...
[ 5808.490367] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-ghash, throttling...
[ 5808.490597] request_module: kmod_concurrent_max (0) close to 0 (max_modprobes: 50), for module crypto-ghash, throttling...
Changed in stress-ng: | |
assignee: | nobody → Colin Ian King (colin-king) |
importance: | Undecided → Medium |
status: | New → In Progress |
Changed in linux (Ubuntu): | |
importance: | Undecided → Low |
Changed in stress-ng: | |
status: | Fix Committed → Fix Released |
I'm not sure this really is a stress-ng issue, the purpose of stress-ng is to force out kernel problems like this. Isn't this a kernel issue instead?