== kernel-side TODO == * --(Rename s/vmtrace/pgtrace/g)-- * Support for multi-process tracing instead of by user uid (discuss) * Add versioning to "struct pgtrace_entry"! (discuss) * Use dcache cookies to transform inode+bdev into path (much easier to work with). At the moment, if files get deleted during the workload you're doomed, having no way to identify deleted inode numbers. * Measure the impact of tracing (relayfs transmission at fault/find_get_page paths, capture daemon, pte unmapping). * Timing: current kptecleaner unmap period is "HZ/2" (but HZ in practice since timer is jiffy clocked). * Alternatives to timer: * "active PTE FIFO". This approach is used by S.F.Kaplan's "vmtrace" tool. Have a FIFO of mapped pte's. Clamp it a certain N size, not allowing more than N pte's to be mapped. Requires unmapping at fault path (touch pte flags, flush TLB). * SMP support: * add CPUID field to entry * one kptecleaner thread per CPU. How to synchronize them? == userspace tools TODO == * Create a Makefile! * vmtrace-split currently splits in per "inode+bdev" type only, should work on uid, pid, pwd, etc. From [[http://nptltracetool.sourceforge.net/|NPTL trace tool]]: * Trace cut : it is possible to work only on a part of the trace selected with a temporal or a numeric criteria. * Trace split : it is possible to split the trace into several files to get either one file per process or one file per thread. * Trace filtering : it is possible to filter the trace on various criteria such as event name, object name, kind of object or pid. * Log levels : it is possible to switch dynamically from a light trace to a richer or full trace. * Large volume of traces : the tool handles large trace files (more than 16 Go). * Continuous recording : the tool can keep only the last traces of the execution. * vmtrace-split opens an unlimited amount of files, it should cap at 1024 open fd's and reuse those on demand. * vmtrace-phase: recognize and classify common access patterns. * Generate visual information such as avg.IRF histograms, address versus time graphs, etc, etc.