On Mon, 10 Nov 2025 16:19:54 -0500 Steven Rostedt <[email protected]> wrote:
> On Thu, 16 Oct 2025 16:46:19 +1100 > Balbir Singh <[email protected]> wrote: > > > Add tracepoints for debugging device migration flow in migrate_device.c. > > This is helpful in debugging how long migration took (time can be > > tracked backwards from migrate_device_finalize to migrate_vma_setup). > > > > A combination of these events along with existing thp:*, exceptions:* > > and migrate:* is very useful for debugging issues related to > > migration. > > > > ... > > > hmm-tests-855 [002] 50.042800: set_migration_pmd: > > addr=7f2908a00000, pmd=dfffffffd39ffe00 > > hmm-tests-855 [002] 50.062345: remove_migration_pmd: > > addr=7f2908a00000, pmd=efffffe00403fe00 > > Each TRACE_EVENT() is equivalent to: > > DECLARE_EVENT_CLASS(event, ...) > DEFINE_EVENT(event, event, ...) > > Where a class is around 4-5K in size, and the DEFINE_EVENT is between > 500 and 1k in size. > > By using a single DECLARE_EVENT_CLASS() for multiple events, you can save > several thousands of bytes of memory. Thanks for the detailed review. I'll drop this version of the patch.
