> But, I have a naive question. Should this be integrated in > some way with the hwpmc work of Joseph Koshy since I think it > could be useful for DTRace to get information from the CPU as > well. Disclaimer: I've only just started reading about DTrace. There appear to be two ways to integrate hwpmc and DTrace: - Augment the D virtual machine with a primitive that can read PMC values (e.g.- using RDPMC or RDMSR instructions on x86 CPUs). Make this primitive available to scripts for allocating and reading from PMCs (say a "pmcread()" builtin function). This approach would work well with counting mode PMCs (both process and system-mode counting PMCs) and would allow PMCs to be read at arbitrary points of time. We'll need a way of allocating system-wide & process-mode PMCs; this could be done in userland (in dtrace(8)). - hwpmc(4) can be augmented to be a 'DTrace provider' allowing D scripts to be run, say when a PC sample is recorded. -- FreeBSD Developer, http://people.freebsd.org/~jkoshyReceived on Fri May 26 2006 - 13:18:56 UTC
This archive was generated by hypermail 2.4.0 : Wed May 19 2021 - 11:38:56 UTC