❦ 6 décembre 2013 10:05 CET, Ondřej Surý <ond...@sury.org> : > could you please elaborate more? What benefits would that have to > general users and is there any performance (or any other) drawbacks in > enabling this?
Such a support allows a user to answers questions like: - how many time do we hit this function? - how long a request whose URI starts with /api takes? - is this function still used? - what is the repartition of request times for my webserver? And all this on production systems with a very low overhead. When the user is not using tracing at all, there is zero impact on performance because it expands to a NOP instruction. Only when a user is requesting to put a probe in action, the NOP will be turned into an appropriate instruction to be trapped by the kernel. See: https://sourceware.org/systemtap/wiki/UserSpaceProbeImplementation -- Make sure comments and code agree. - The Elements of Programming Style (Kernighan & Plauger)
signature.asc
Description: PGP signature
