On Wednesday 13 February 2008 03:35, Nicholas Nethercote wrote: > On Wed, 13 Feb 2008, Julian Seward wrote: > > In addition, I'd bet that most stack frames are a lot smaller > > than a page, so the caching is also spatially effective: if we > > know that this frame is safe to poke around in, then it's likely > > that the next frame is in the same page and so we don't even need > > to ask aspacem about its safety. > > Perhaps you could ask for the extent of the contiguous addressable memory > around the particular address?
Yes, that would I guess be a logical generalisation. It does however put the administrative burden more on the caller, since then the caller first has to ask how big is the accessible area in which address X lies; then keep track of when it has gone outside the area, in which case it needs to ask again, etc. Also, the caller(s) have no obvious way to know when any information they have cached, has gone stale. It would be simpler for the caller if all such trickery were pushed into the is-this-page-safe function and we took care to ensure that said function returned extremely quickly in the majority of cases. J ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ Valgrind-developers mailing list Valgrind-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/valgrind-developers
