Messages in this thread | | | Subject | Re: [PATCH v3 0/9] trace_uprobe: Support SDT markers having reference count (semaphore) | From | Ravi Bangoria <> | Date | Thu, 3 May 2018 14:02:00 +0530 |
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On 04/17/2018 10:02 AM, Ravi Bangoria wrote: > Userspace Statically Defined Tracepoints[1] are dtrace style markers > inside userspace applications. Applications like PostgreSQL, MySQL, > Pthread, Perl, Python, Java, Ruby, Node.js, libvirt, QEMU, glib etc > have these markers embedded in them. These markers are added by developer > at important places in the code. Each marker source expands to a single > nop instruction in the compiled code but there may be additional > overhead for computing the marker arguments which expands to couple of > instructions. In case the overhead is more, execution of it can be > omitted by runtime if() condition when no one is tracing on the marker: > > if (reference_counter > 0) { > Execute marker instructions; > } > > Default value of reference counter is 0. Tracer has to increment the > reference counter before tracing on a marker and decrement it when > done with the tracing.
Hi Oleg, Masami,
Can you please review this :) ?
Thanks.
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