Messages in this thread | | | Date | Fri, 25 Sep 2020 12:08:05 -0700 | Subject | [RFC PATCH 0/1] tracing: support dynamic string field types for synthetic events | From | Axel Rasmussen <> |
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Hi Steven and Tom,
In this thread: https://lkml.org/lkml/2020/9/17/1015 we discussed how to plumb dynamic strings into synthetic events. Tom, you proposed adding a new dynamic string type to synthetic event definition like "char foo[]".
I'm sending this patch because it may be simpler than implementing that (I'm not too familiar with the tracing infrastructure, apologies if this is not true), and in my testing it seems sufficient to address my use case. I tested both setting up a synthetic event as Steven described in the other thread, as well as doing an analogous thing with a small bpftrace program, and both work as expected with this patch.
This is because I happen to know there's an upper bound on the length of the string in question, so I can just define a "char memcg_path[256]" in the synthetic event, and I can be sure the string won't be truncated.
Let me know what you think. Happy to drop this and wait for Tom's suggested approach instead.
Axel Rasmussen (1): tracing: support dynamic string field types for synthetic events
kernel/trace/trace_events_hist.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-)
-- 2.28.0.681.g6f77f65b4e-goog
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