Hi Axel, On Wed, 2020-09-30 at 15:45 -0700, Axel Rasmussen wrote: > I still get the same WARN_ON behavior when trying to use bpftrace. > But, I spent some time today reading through that call path, and at > this point I'm convinced that it's the version of bpftrace I'm using > which is slightly broken, not the kernel in this case. (To be fair, > I'm trying to use some unreleased tip-of-tree version of it, with > some > not-yet-merged patches, and some extra hacks on top of all that, so > it's not particularly surprising...) > > In my experiments with just the synthetic event + histogram triggers, > this patchset works as expected for my use case. > > So (for the whole series, not just this one patch): > > Tested-by: Axel Rasmussen <axelrasmus...@google.com>
Thanks! Tom > > On Wed, Sep 30, 2020 at 11:41 AM Tom Zanussi <zanu...@kernel.org> > wrote: > > > > 32 is too small for this value, and anyway it makes more sense to > > use > > MAX_FILTER_STR_VAL, as this is also the value used for variable- > > length > > __strings. > > > > Signed-off-by: Tom Zanussi <zanu...@kernel.org> > > --- > > kernel/trace/trace_synth.h | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/kernel/trace/trace_synth.h > > b/kernel/trace/trace_synth.h > > index ac35c45207c4..5166705d1556 100644 > > --- a/kernel/trace/trace_synth.h > > +++ b/kernel/trace/trace_synth.h > > @@ -7,7 +7,7 @@ > > #define SYNTH_SYSTEM "synthetic" > > #define SYNTH_FIELDS_MAX 32 > > > > -#define STR_VAR_LEN_MAX 32 /* must be multiple of > > sizeof(u64) */ > > +#define STR_VAR_LEN_MAX MAX_FILTER_STR_VAL /* must > > be multiple of sizeof(u64) */ > > > > struct synth_field { > > char *type; > > -- > > 2.17.1 > >