On Sun, 16 Nov 2008 16:56:09 +0100 Bernhard Walle <bwalle@xxxxxxx> wrote: > > > While the original submission of CONFIG_STRICT_DEVMEM mentions > > > that the option has been in RHEL and Fedora for 4 years without > > > problems, that's only a half of the story. The truth is that at > > > least RHEL has /dev/crash exactly to circumvent that /dev/mem > > > restriction. Don't tell me that this is better than having that > > > sysctl entry. ;-) > > > > I assume /dev/crash is read only > > I don't know. But if that matters, why can't we make /dev/mem > write-only for certain areas and read-only for the rest ...? > > > You either want this at compile time or you don't want it at all. > > Why? You don't write something about my arguments (as Alan does, even > though I disagree), you only write that you "nak" it. It's very simple: if you want the strict form you really want the strict form, not some half "oh but it's one line to turn off" form. (Note: your usecase is in trouble in general already with PAT used by modern video drivers: the requirement is that all mappings of the same physical page are mapped with the same cachability semantics. mmaping random parts of physical real memory via /dev/mem makes that a way too complex issue and will likely turn the crash utility in what it's name says ;-) -- Arjan van de Ven Intel Open Source Technology Centre For development, discussion and tips for power savings, visit http://www.lesswatts.org -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
