Messages in this thread | | | Subject | Re: ftrace introduces instability into kernel 2.6.27(-rc2,-rc3) | From | Benjamin Herrenschmidt <> | Date | Wed, 20 Aug 2008 11:17:28 +1000 |
| |
On Tue, 2008-08-19 at 16:58 -0700, Jeremy Fitzhardinge wrote: > Benjamin Herrenschmidt wrote: > >> Ok, there are two cases where it's ok : > >> > >> 1 - in stop_machine, considering we are not touching code executed in > >> NMI handlers. > >> 2 - when using my replace_instruction_safe() which uses a temporary > >> breakpoint when doing the instruction replacement. > >> > >> In those cases you could use text_poke_early(). > >> > > > > Note that vmap/vunmap will be very slow. > > > > Don't we have Nick's speedups now?
Not sure what speedups this is, but it's stlil not something you want to do a lot ... setting up and tearing down MMU mappings isn't something I'd like to see happening on a per-mcount basis.
Ben
| |