On Thu, Sep 01, 2022 at 09:05:36AM +0200, Peter Zijlstra wrote: > On Wed, Aug 31, 2022 at 11:59:41AM -0400, Kent Overstreet wrote: > > > Also, ftrace can drop events. Not really ideal if under system load your memory > > accounting numbers start to drift. > > You could attach custom handlers to tracepoints. If you were to replace > these unconditional code hooks of yours with tracepoints then you could > conditionally (say at boot) register custom handlers that do the > accounting you want. > > Nobody is mandating you use the ftrace ringbuffer to consume tracepoints. > Many people these days attach eBPF scripts to them and do whatever they > want. Look at kernel/trace/blktrace.c for a fine in-kernel !BFP example of this.