| Message ID | 20191207.160457.297470232945357742.davem@davemloft.net |
|---|---|
| State | RFC |
| Delegated to: | BPF Maintainers |
| Headers | show |
| Series | bpf: Make RT friendly. | expand |
diff --git a/kernel/bpf/stackmap.c b/kernel/bpf/stackmap.c index caca752ee5e6..d49b5f184082 100644 --- a/kernel/bpf/stackmap.c +++ b/kernel/bpf/stackmap.c @@ -288,10 +288,17 @@ static void stack_map_get_build_id_offset(struct bpf_stack_build_id *id_offs, struct stack_map_irq_work *work = NULL; if (irqs_disabled()) { +#ifdef CONFIG_PREEMPT_RT_FULL + /* We cannot use the up_read_non_owner() interface in RT + * kernels, so just force reporting of IPs. + */ + irq_work_busy = true; +#else work = this_cpu_ptr(&up_read_work); if (work->irq_work.flags & IRQ_WORK_BUSY) /* cannot queue more up_read, fallback */ irq_work_busy = true; +#endif } /*
In the RT kernel we can't use up_read_non_owner(). So in such a configuration, simply elide the annotated stackmap and just report the raw IPs. In the longer term, we can make atomic friendly versions of the page cache traversal which will at least provide the info if the pages are resident and don't need to be paged in. Signed-off-by: David S. Miller <davem@davemloft.net> --- kernel/bpf/stackmap.c | 7 +++++++ 1 file changed, 7 insertions(+)