On Wed, Jan 30, 2019 at 11:32:43AM -0800, Alexei Starovoitov wrote:
> On Wed, Jan 30, 2019 at 11:10:58AM +0100, Peter Zijlstra wrote:
> >
> > Why do you say this is not possible? All you need is 3 CPUs, one doing a
> > CPU online, one doing a perf ioctl() and one doing that
> > bpf_probe_register(
On Wed, Jan 30, 2019 at 11:10:58AM +0100, Peter Zijlstra wrote:
>
> Why do you say this is not possible? All you need is 3 CPUs, one doing a
> CPU online, one doing a perf ioctl() and one doing that
> bpf_probe_register().
yeah. indeed. I'm impressed that lockdep figured it out
while I missed it
On Wed, Jan 30, 2019 at 11:10:58AM +0100, Peter Zijlstra wrote:
> On Tue, Jan 29, 2019 at 08:04:57PM -0800, Alexei Starovoitov wrote:
> > Lockdep warns about false positive:
>
> The report reads like:
>
> tracepoint_probe_register()
> #0 mutex_lock(&tracepoint_mutex)
> tracepoi
On Tue, Jan 29, 2019 at 08:04:57PM -0800, Alexei Starovoitov wrote:
> Lockdep warns about false positive:
The report reads like:
tracepoint_probe_register()
#0mutex_lock(&tracepoint_mutex)
tracepoint_add_func()
static_key_slow_inc()
#1cpus_read_lo
Lockdep warns about false positive:
[ 13.007000] WARNING: possible circular locking dependency detected
[ 13.007587] 5.0.0-rc3-00018-g2fa53f892422-dirty #477 Not tainted
[ 13.008124] --
[ 13.008624] test_progs/246 is trying to acquire lock
