On Tue, 9 Feb 2021 14:55:31 -0500 Steven Rostedt <rostedt@xxxxxxxxxxx> wrote: > > [for-next][PATCH 2/2] tracing: Use temp buffer when filtering events > > https://lore.kernel.org/lkml/f16b14066317f6a926b6636df6974966@xxxxxxxxxxxxxx/ > > Note, that is only used when filtering happens, which doesn't appear to be > the case here. I was basing this off of the original commands, but the stack dump says otherwise. But it should still work. > > > > > It seems like we should still try to get that fixed somehow, even if > > the below change is fine on its own (it probably doesn't make sense to > > such a large amount of data via tracepoints). It would be unfortunate > > for next poor soul to hit the same issues, just because they wanted to > > dump a few KB. > > Yeah, it was a design decision to cap the max size of events to just under > PAGE_SIZE. The ring buffer is broken up into pages (for zero copy > transfers to file systems and the network). Thus, no event is allowed to be > bigger than a page (and actually a bit smaller) > > That said, it shouldn't have crashed, it should have just failed to record. > > I'll test it out and see why it crashed. Looking at the original report, I see: CPU: 1 PID: 141 Comm: kworker/u16:1 Not tainted 4.19.139 #162 Does this still crash on the latest kernel? -- Steve
