On Sat, Jan 28, 2012 at 8:58 AM, Ali Saidi <[email protected]> wrote: > > On Jan 28, 2012, at 3:00 AM, Gabe Black wrote: > > > > >>> My discussion of the general compile-time mechanism is just to > emphasize > >>> that the maintenance of this one aspect of the current SE/FS > difference is > >>> a stopgap replacement for this alternate ideal, not a perpetuation of > the > >>> now-meaningless distinction that Gabe has worked so hard to eradicate, > so > >>> that he doesn't accuse me of bitterly clinging to the past... > >> Ok, but I'd really hate to see this delay Gabe long enough that we > >> don't ever get it into the tree. Gabe, do you think it'd be easy to > >> cook up what Steve is talking about? (Or does it already work in your > >> tree?) > >> > > > > I'll try adding an option that leaves out the devices since I assume > > that's where the extra time is coming from. I'm thinking if you set > > NO_DEVICES on the scons command line it will leave the devices out of > > the build. That won't be set by default on anything since the same build > > is used for both SE and FS and it doesn't make sense as a default, but > > if you're using it for SE style stuff and build time is affected enough > > for you to find out about that option, then it'll be available. There > > may be complications so no promises. It may also not close recover the > > build time, but I expect it will. > I think that adding these sorts of things is going to create more > confusion that it's worth. We're going to have people who compile with > NO_DEVICE and don't understand why they can't run full-system code (or the > random error we're going to produce about not being able to create a > simobject) and we're going to have a group of people who don't know > NO_DEVICE exists and so they never use it. A 30% compile time increase the > first time you compile "SE" mode doesn't seem bad. The device models > shouldn't need re-compile, so any further development for SE activities > shouldn't effect them. This simples something that confuses a reasonable > fraction of users (What is SE and FS?) and speeds up compiles tremendously > for those of us who compile multiple binaries frequently.
If, as Gabe suggests, we maintain some of the SE conditional compilation flags as NO_DEVICES, but don't expose that flag directly by including it in any of the "official" named builds, then I expect that only people who know what they're doing will ever use it. So I don't see it adding to the confusion. Also, as I mentioned before, the argument about "it's only the first time you compile" only really cuts it if scons magically becomes both bug-free and omniscient. Steve _______________________________________________ gem5-dev mailing list [email protected] http://m5sim.org/mailman/listinfo/gem5-dev
