Hello, I'm not aware of the context of this patch, but please note that the amount of overhead from non-empty LD_AUDIT is currently extremely high in all released Glibc versions. The forced high overhead is, as I understand, misaligned with LTTng's aim to provide low-overhead tracing.
Non-empty LD_AUDIT behaves as if one of auditing libraries provided PLT hooks. This causes the dynamic linker to install register save-restore helpers for each PLT call, even if they are not needed (if no PLT hooks were in fact provided). Here's the Glibc bug that shows a ~19x slowdown on a microbenchmark that repeatedly calls sqrt() from libm.so. The proposed patch was not accepted, with the review suggesting a different approach. https://sourceware.org/bugzilla/show_bug.cgi?id=15533 Could you explain the problem your patch aims to solve? Sorry if it was already explained elsewhere; please point me to the discussion in that case. Alexander _______________________________________________ lttng-dev mailing list [email protected] http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev
