On Mon, 2015-09-07 at 10:59 +0000, David Laight wrote: > From: Michal Sojka > > >> I think GCC uses memcpy() in well known situations like initialising > > >> structures or copying structures. > > >> Shouldn't we just avoid this kind of actions in the very few early init > > >> functions ? > > > Which are the "very few" early init functions? Can you make a list, for > > > 32-bit > > > and 64-bit? And can we keep it updated over time and not introduce > > > regressions? > > > > > If the code that runs without caches is concentrated in few files, we > > may either modify the buildsystem to check whether there is a call to > > memcpy from these files (e.g. by using nm) or these files can be > > "prelinked" with special version of memcpy that doesn't require caches. > > Would any of these be acceptable? > > What about run-time patching memcpy() after the caches are initialised?
Yeah, that's the solution we use on 64-bit. It also means you can have cpu specific optimisations, which can be patched in or out using the cpu feature patching. cheers _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
