codel_dump_stats() only runs with RTNL held,
reading fields that can be changed in qdisc fast path.
Add READ_ONCE()/WRITE_ONCE() annotations.
Alternative would be to acquire the qdisc spinlock, but our long-term
goal is to make qdisc dump operations lockless as much as we can.
tc_codel_xstats fields don't need to be latched atomically,
otherwise this bug would have been caught earlier.
No change in kernel size:
$ scripts/bloat-o-meter -t vmlinux.0 vmlinux
add/remove: 0/0 grow/shrink: 1/1 up/down: 3/-1 (2)
Function old new delta
codel_qdisc_dequeue 2462 2465 +3
codel_dump_stats 250 249 -1
Total: Before=29739919, After=29739921, chg +0.00%
Fixes:
|
||
|---|---|---|
| .. | ||
| acpi | ||
| asm-generic | ||
| clocksource | ||
| crypto | ||
| cxl | ||
| drm | ||
| dt-bindings | ||
| hyperv | ||
| keys | ||
| kunit | ||
| kvm | ||
| linux | ||
| math-emu | ||
| media | ||
| memory | ||
| misc | ||
| net | ||
| pcmcia | ||
| ras | ||
| rdma | ||
| rv | ||
| scsi | ||
| soc | ||
| sound | ||
| target | ||
| trace | ||
| uapi | ||
| ufs | ||
| vdso | ||
| video | ||
| xen | ||
| Kbuild | ||